home Tests What is acetylcholine? The effect of acetylcholine. Biochemistry and Molecular Biology: Textbook

What is acetylcholine? The effect of acetylcholine. Biochemistry and Molecular Biology: Textbook

Irreversible inhibition of cholinesterase causes death. Cholinesterase inhibitors are organophosphorus compounds (chlorophos, dichlorvos, tabun, sarin, soman, binary poisons). These substances bind covalently to serine at the active site of the enzyme. Some of them are synthesized as insecticides, and some as CWAs (nerve poisons). Death occurs as a result of respiratory arrest.

Reversible cholinesterase inhibitors are used as therapeutic drugs. For example, in the treatment of glaucoma and intestinal atony.

CATECHOLAMINES: norepinephrine and dopamine.

Adrenergic synapses are found in postganglionic fibers, in the fibers of the sympathetic nervous system, in various parts of the brain. Catecholamines in nervous tissue are synthesized according to common mechanism from tyrosine. The key enzyme in the synthesis is tyrosine hydroxylase, which is inhibited by end products.

NORADRENALIN is a mediator in the postganglionic fibers of the sympathetic and in various parts of the central nervous system.

DOPAMINE is a mediator of pathways, the bodies of neurons of which are located in the part of the brain that is responsible for controlling voluntary movements. Therefore, when dopaminergic transmission is disturbed, the disease parkinsonism occurs.

Catecholamines, like acetylcholine, accumulate in synaptic vesicles and are also released into the synaptic cleft upon admission. nerve impulse. But the regulation in the adrenergic receptor occurs differently. In the presynaptic membrane there is a special regulatory protein - alpha-achromogranin (Mm = 77 kDa), which, in response to an increase in the concentration of the mediator in the synaptic cleft, binds the already released mediator and stops its further exocytosis. There is no enzyme that destroys the neurotransmitter in adrenergic synapses. After the momentum is transferred, the mediator molecule is pumped by a special transport system by active transport with the participation of ATP back through the presynaptic membrane and is included again in the vesicles. In the presynaptic nerve ending, the excess of the mediator can be inactivated by MAO, as well as by catecholamine-O-methyltransferase by methylation at the hydroxy group. Cocaine inhibits the active transport of catecholamines.

Signal transmission in adrenergic synapses proceeds according to the mechanism known to you from the lectures on the topic “Biochemistry of hormones” with the participation of the adenylate cyclase system. The binding of the mediator to the postsynaptic receptor almost instantly causes an increase in the concentration of cAMP, which leads to rapid phosphorylation of the proteins of the postsynaptic membrane. As a result, the generation of nerve impulses by the postsynaptic membrane changes (it is inhibited). In some cases, the direct cause of this is an increase in the permeability of the postsynaptic membrane for potassium, or a decrease in conductivity for sodium (these events lead to hyperpolarization).

Acetylcholinesterase an enzyme that breaks down a neurotransmitter acetylcholine.

Acetylcholine is released from the presynapse into the synaptic cleft and binds to a receptor on the postsynapse, thus effecting signal transmission between nerve cells. To transmit a new signal, it is necessary to remove the "spent" acetylcholine from the synaptic cleft. Acetylcholinesterase catalyzes the hydrolysis of acetylcholine to choline and acetic acid. From choline, a new acetylcholine is subsequently synthesized.

Disruption of the cholinergic systems is associated with various neurodegenerative diseases. Blocking acetylcholinesterase leads to the accumulation of acetylcholine and, consequently, increased transmission of excitation, which makes this enzyme a promising therapeutic target in drug development. Acetylcholinesterase inhibitor donepezil, used in the treatment of Alzheimer's disease, helps to reduce the symptoms of the disease.

Irreversible blocking of acetylcholinesterase underlies the mechanism of action of deadly poisonous substances: sarin, some snake venoms, organophosphate insecticides, V-gases.

Molecule models of acetylcholinesterase and its inhibitor donepezil

Formed in the body (endogenous) acetylcholine plays an important role in life processes: it promotes the transmission nervous excitement in the central nervous system, autonomic ganglia, endings of parasympathetic (motor) nerves. Acetylcholine is a chemical transmitter (mediator) of nervous excitation; the endings of the nerve fibers for which it serves as a mediator are called cholinergic, and the receptors that interact with it are called cholinergic receptors. Cholinergic receptors are complex protein molecules (nucleoproteins) of a tetrameric structure, localized on the outer side of the postsynaptic (plasma) membrane. By nature, they are heterogeneous. Cholinergic receptors located in the area of postganglionic cholinergic nerves (heart, smooth muscles, glands) are designated as m-cholinergic receptors (muscarinic-sensitive), and located in the area of ganglionic synapses and in somatic neuromuscular synapses - as n-cholinergic receptors (nicotine-sensitive) (S. V . Anichkov). This division is associated with the peculiarities of the reactions that occur during the interaction of acetylcholine with these biochemical systems, muscarine-like (lowering blood pressure, bradycardia, increased secretion of the salivary, lacrimal, gastric and other exogenous glands, constriction of the pupils, etc.) in the first case and nicotine-like ( contraction of skeletal muscles, etc.) in the second. M- and n-cholinergic receptors are localized in various organs and systems of the body, including the central nervous system. Muscarinic receptors have been divided in recent years into a number of subgroups (m1, m2, m3, m4, m5). The localization and role of m1 and m2 receptors is currently the most studied. Acetylcholine does not have a strictly selective effect on various cholinergic receptors. To one degree or another, it affects m- and n-cholinergic receptors and subgroups of m-cholinergic receptors. The peripheral muscarine-like action of acetylcholine is manifested in slowing heart rate, dilating peripheral blood vessels and lowering blood pressure, activating the peristalsis of the stomach and intestines, contracting the muscles of the bronchi, uterus, gallbladder and bladder, increasing the secretion of the digestive, bronchial, sweat and lacrimal glands, constriction of the pupils ( miosis). The latter effect is associated with increased contraction of the circular muscle of the iris, which is innervated by postganglionic cholinergic fibers of the oculomotor nerve (n. oculomotorius). At the same time, as a result of the contraction of the ciliary muscle and the relaxation of the ligament of the ciliary girdle, a spasm of accommodation occurs. Pupil constriction due to the action of acetylcholine is usually accompanied by a decrease in intraocular pressure. This effect is partly explained by pupil dilation and flattening of the iris of the Schlemm's canal (venous sinus of the sclera) and fountain spaces (iriocorneal angle spaces), thereby improving the outflow of fluid from the internal media of the eye. It is possible, however, that other mechanisms are also involved in the reduction of intraocular pressure. Due to their ability to reduce intraocular pressure, substances that act like acetylcholine (cholinomimetics, anticholinesterase drugs) are widely used to treat glaucoma1. The peripheral nicotine-like effect of acetylcholine is associated with its participation in the transmission of nerve impulses from preganglionic fibers to postganglionic fibers in the autonomic nodes, as well as from motor nerves to striated muscles. In small doses, it is a physiological transmitter of nervous excitation, in large doses it can cause persistent depolarization in the synapse region and block the transmission of excitation. Acetylcholine also plays an important role as a mediator in the central nervous system. It is involved in the transmission of impulses in different parts of the brain, while in small concentrations it facilitates, and in large concentrations it inhibits synaptic transmission. Changes in the metabolism of acetylcholine can lead to impaired brain function. Some of its centrally acting antagonists are psychotropic drugs. An overdose of acetylcholine antagonists can cause disturbances in higher nervous activity (hallucinogenic effect, etc.). Acetylcholine chloride (Acetylcholini chloridum) is produced for use in medical practice and experimental studies.

at cholinergic synapses (parasympathetic nerves, preganglionic sympathetic fibers, ganglia, all somatic) the transmission of excitation is carried out by the mediator acetylcholine. Acetylcholine is formed from choline and acetylchoenzyme A in the cytoplasm of cholinergic nerve endings.

Cholinergic receptors, excited by acetylcholine, have unequal sensitivity to certain pharmacological agents. This is the basis for the selection of the so-called: 1) muscarine-sensitive and 2) nicotine sensitive cholinergic receptors, that is, M- and H- cholinergic receptors. M - X olinoreceptors are located in the postsynaptic membrane of cells of effector organs at the endings postganglionic cholinergic (parasympathetic) fibers, as well as in the central nervous system (cortex, reticular formation). H - X olinoreceptors are located in the postsynaptic membrane of ganglion cells at the endings of all preganglionic fibers (in the sympathetic and parasympathetic ganglia), the adrenal medulla, the carotid sinus zone, the end plates of skeletal muscles and the central nervous system (in the neurohypophysis, Renshaw cells, etc.). Sensitivity to pharmacological substances of various N-cholinergic receptors is not the same, which makes it possible to distinguish N-cholinergic receptors ganglia and N-cholinergic receptors skeletal muscles.

MECHANISM OF ACTION OF ACETYLCHOLINE. Interacting with cholinergic receptors and by changing their conformation, Tilcholine changes the permeability of the postsynaptic membrane. With the excitatory effect of acetylcholine, Na ions penetrate into the cell, leading to depolarization of the postsynaptic membrane. This is manifested by a local synaptic potential, which, having reached a certain value, generates an action potential. Local excitation, limited to the synaptic region, spreads throughout the cell membrane (secondary messenger - cyclic guanosine monophosphate- cGMP).

The action of acetylcholine is very short-lived, it is destroyed (hydrolyzed) by the enzyme acetylcholinesterase.

Medicinal substances can affect the following stages of synaptic transmission: 1) the synthesis of acetylcholine; 2) the mediator release process; 3) interaction of acetylcholine with cholinergic receptors; 4) enzymatic hydrolysis of acetylcholine;

5) capture presynapric endings of choline formed during the hydrolysis of acetylcholine.

CLASSIFICATION OF CHOLINERGICS

I. M-, N-cholinomimetic agents

Acetylcholine - carbocholine

II. M-cholinomimetic agents (anticholinesterase agents, AChE)

a) reversible

- prozerin - galantamine - physostigmine - oxazil - edrophonium - pyridostigmine b) irreversible action - phosphakol - armin - insecticides (chlorophos, karbofos, dichlorvos) - fungicides (pesticides, defoliants) - chemical warfare agents (sarin, zaman, tabun)

III. M-cholinomimetics

Pilocarpine - aceclidine - muscarine

IV. M- anticholinergics (drugs of the atropine group)

a) non-selective - atropine - scopolamine - platifillin - metacin

b) selective ( M-anticholinergics)pirenzipine (gastrocepin)

v. N-cholinomimetics - cytiton - lobelin - nicotine

VI. N-anticholinergics a) ganglion blockers- benzohexonium - pyrylene - hygronium - arfonad - pentamine

b) muscle relaxants - tubocurarine - pancuronium - anatruxonium - dithylin

Let us analyze the group of means related to M-, N-cholinomimetics. To means directly stimulating M- and N-cholinergic receptors(M-, N-cholinomimetics) include acetylcholine and its analogues (carbacholine). Acetylcholine, is a mediator in cholinergic synapses, is an ester of choline and acetic acid and belongs to monoquaternary ammonium compounds.

As a drug, it is practically not used, since it acts sharply, quickly, almost instantly, very briefly (minutes). When taken orally, it is ineffective, since hydrolyzed. In the form of chloride, acetylcholine is used in experimental physiology and pharmacology.

Acetylcholine has a direct stimulating effect on M- and H- cholinergic receptors. With the systemic action of acetylcholine (in / in the introduction is unacceptable, since the blood pressure drops sharply), M-cholinomimetic effects prevail: bradycardia, vasodilation, increased tone and contractile activity of the muscles of the bronchi, gastrointestinal tract. These effects are similar to those observed when the corresponding cholinergic (parasympathetic) nerves are irritated. The stimulating effect of acetylcholine on N-cholinergic receptors autonomic ganglia also takes place, but it is masked M-cholinomimetic action. Acetylchline has a stimulating effect on N-cholinergic receptors skeletal muscles.

In connection with the above, in the future we will focus on anticholinesterase agents. Anticholinesterase drugs (AChE) are drugs that exert their effect by inhibiting, blocking acetylcholinesterase. Inhibition of the enzyme is accompanied by the accumulation of the mediator acetylcholine in the synapse area, that is, in the area cholinergic receptors. Under the influence of anticholinesterase agents, the rate of destruction of acetylcholine slows down, which exhibits a longer effect on Mi. N-cholinergic receptors. Thus, these drugs act similarly to M, N-cholinomimetics, but the effect of anticholinesterase agents is mediated through endogenous (own) acetylcholine. This is the main mechanism of action anticholinesterase funds. It should be added that these agents also have some direct stimulating effect on M, N-cholinergic receptors.

Based on the stability of the interaction of anticholinesterase drugs with acetylcholinesterase, they are divided into 2 groups:

1) AChE means of reversible action. Their action lasts 2-10 hours. These include: physostigmine, prozerin, galantamine and others.

2) AChE means of an irreversible type of action. These agents are very strongly associated with acetylcholinesterase for many days, even months. However, gradually, after about 2 weeks, enzyme activity can be restored. These agents include: armin, phosphakol and other anticholinesterase agents from the phosphorus group organic compounds(insecticides, fungicides, herbicides, BOV).

The reference remedy for a group of reversibly acting AChE drugs is PHYSOSTIGMIN (it has been used for a long time as a weapon and as a means of justice, since according to legend, only a truly guilty person dies from poison), which is a natural alkaloid from Calabar beans, i.e., dried mature seeds West African climbing tree Physotigma venenosum. In our country, PROZERIN is more often used (tablets of 0.015; ampoules of 1 ml of 0.05%, in eye practice - 0.5%; Proserinum), which, like other means of this group (galantamine, oksazil, edrophonium, etc. .), a synthetic compound. Prozerin chemical structure is a simplified analogue of physostigmine containing a quaternary ammonium group. This distinguishes it from physostigmine. In connection with unidirectionality the actions of all the listed drugs they will have almost common effects.

Of considerable practical interest is the effect of AChE agents, both natural and synthetic, on some functions: 1) eyes; 2) tone and motility of the gastrointestinal tract; 3) neuromuscular transmission; 4) bladder; 5) CNS.

First of all, let's analyze the effects prozerinassociated with its effect on M-cholinergic receptors. Anticholinesterase funds, in particular prozerin, affect the eye as follows:

a) cause pupillary constriction (miosis - from the Greek - myosis - closing), which is connected mediated excitement M-cholinergic receptors circular muscle of the iris (m. sphincter pu p illae) and contraction of this muscle;

b) reduce intraocular pressure, which is the result of miosis. At the same time, the iris becomes thinner, the angles of the anterior chamber of the eye open to a greater extent and, as a result, the outflow (reabsorption) of intraocular fluid through the Fountain spaces and Schlemm's canal improves.

in) prozerin, like all AChE, causes a spasm of accommodation (devices). In this case, the funds indirectly stimulate M - X olinoreceptors of the ciliary muscle (m. ciliaris), which has only cholinergic innervation. Contraction of this muscle relaxes the ligament of Zinn and, accordingly, increases the curvature of the lens. The lens becomes more convex, and the eye is set to the near point of vision (he sees poorly in the distance). Based on the foregoing, it becomes clear why prozerin is sometimes used in ophthalmic practice. In this regard, prozerin is indicated for open-angle form of glaucoma (0.5% solution 1-2 drops 1-4 times a day).

Prozerinhas a stimulating effect on the tone and motor activity (peristalsis) of the gastrointestinal tract, thereby improving the promotion of contents, enhances the tone of the bronchi (causes bronchospasm), as well as the tone and contractile activity of the ureters. In a word, AChE, in particular prozerin, increase the tone of all smooth muscle organs. In addition, prozerin enhances the secretory activity of the external secretion glands (salivary, bronchial, intestines, sweat) due to acetylcholine.

CARDIOVASCULARSYSTEM. Prozerin usually reduces the heart rate and tends to lower blood pressure.

The use of prozerin in clinical practice is associated with its listed pharmacological effects. Due to its tonic effect on the tone and contractile activity of the intestines and bladder, the drug is used to eliminate postoperative atony of the intestines and bladder. On the mean in the form of tablets or injections under the skin.

EFFECTS OF PROZERIN (AChE) UNDER ACTION ON N-CHOLINORECEPTORS (NICOTINE-LIKE EFFECTS). Nicotine-like the effects of prozerin are manifested in the relief of:

1) neuromuscular transmission

2) transmission of excitation in the autonomic ganglia As a result, prozerin causes a significant increase in the strength of contraction of skeletal muscles, and due to this it is indicated for use in patients with myasthenia gravis. Miasthenia gravis is a neuromuscular disease with two characteristic, parallel processes:

a) damage to muscle tissue by the type of polymyositis (autoimmune disorders);

b) damage to synaptic conduction, synaptic block (synthesis of Acetylcholine is less, difficulty in its release, insufficient sensitivity of receptors). Clinic: muscle weakness and severe fatigue. In addition, the drug is used in neurological practice for paralysis, paresis that occurs after mechanical injuries, after poliomyelitis (residual effects), encephalitis, optic neuritis, and neuritis. Due to the fact that prozerin facilitates the transmission of excitation in the autonomic ganglia, it is indicated for poisoning ganglion blockers. In addition, prozerin is effective in overdose of muscle relaxants (muscle weakness, respiratory depression) antidepolarizing actions (in / in up to 10-12 ml of 0.05% solution) for example, d-tubocurarine. Sometimes prozerin is prescribed for weakness of labor activity (previously more often, now very rarely). As you can see, the drug has a wide range of activities, and therefore there are side reactions.

Side effects: the effect of a single dose of prozerin appears after 10 minutes and lasts up to 3-4 hours. In case of overdose or hypersensitivity, there may be such undesirable reactions as increased intestinal tone (up to diarrhea), bradycardia, bronchospasm (especially in people prone to this).

The choice of AChE drugs is determined by their activity, ability to penetrate tissue barriers, duration of action, presence of irritating properties, and toxicity. For glaucoma, prozerin, physostigmine, phosphacol are used. It should be emphasized that galanthamine is not used for this purpose, since it has an irritant effect and causes swelling of the conjunctiva. GALANTAMINE - a Caucasian snowdrop alkaloid - has practically the same indications for use as prozerin. Due to the fact that it penetrates the BBB better (a tertiary amine, and not a quaternary one, like proserin), it is more indicated in the treatment of residual effects after polio.

For resorptive action, PYRIDOSTIGMIN and OXAZIL are prescribed (that is, actions after absorption), the effect of which is longer than prozerin. Contraindications: epilepsy, hyperkinesia, bronchial asthma, angina pectoris, atherosclerosis, in patients with impaired swallowing and breathing.

THE SECOND GROUP OF AChE MEANS - AChE means of an "irreversible" type of action. Here, in essence, one medicine, an organophosphorus compound - an organic ester of phosphoric acid - PHOSPHACOL. Phosphacolum - 10 ml bottles of 0.013% and 0.02% solutions. The highest toxicity is characteristic of the drug, therefore it is used only locally in from phalmological practice. Hence the indications for use:

1) acute and chronic glaucoma;

2) with perforation of the cornea; prolapse of the lens (artificial lens, long miosis is needed). Pharmacological effects are the same as those of prozerin in relation to the eye. It should be said that in ophthalmology solutions of prozerin and phosphacol are rarely used at present.

The second drug - armin (Arminum) - an ester of ethylphosphonic acid, FOS is included in the group of potent, long-acting drugs. It has a high toxicity (hyperactivation of cent-ac insecticides, fungicides, herbicides, since it is essentially ral and peripheral cholinergic systems). In small cases, the number of poisonings with these substances has ended. concentrations is used as a local miotic and antiglaucoma Pharmacological effects organic compounds phosphorus drug. It is produced in the form of eye drops (0.01% solution, 1-2 drops are dripped with the accumulation of endogenous (own) acetylcholine in tissue 2-3 times a day). consequence of persistent inhibition acetylcholinesterase. Acute Other OPs, such as insecticides, fungicides, and herbicides, are of considerable interest to the doctor, as the number of poisonings with these substances has increased significantly.

The pharmacological effects of organic phosphorus compounds are due to the accumulation of endogenous (total) acetylcholine in tissues due to persistent inhibition acetylcholinesterase. Acute OP poisoning requires immediate attention.

SIGNS OF PHOS AND AChE POISONING WITH SUBSTANCES IN GENERAL. OPC poisoning has a very characteristic clinical picture. The patient's condition is usually severe. The effects of muscarinic and nicotine type are noted. First of all, the patient is found:

1) spasm of the pupil ( miosis); 2) severe spasm of the gastrointestinal tract (tenesmus, abdominal pain, diarrhea, vomiting, nausea); 3) severe bronchospasm, suffocation; 4) hypersecretion of all glands (salivation, pulmonary edema - gurgling, wheezing, feeling of tightness in the chest, shortness of breath); 5) the skin is wet, cold, sticky.

All of the above effects are associated with arousal. M-cholinergic receptors(muscarinic effects) and correspond to the clinic in case of poisoning with mushrooms (fly agaric) containing muscarine.

Nicotinic effects are manifested by convulsions, twitching of muscle fibers, contractions of individual muscle groups, general weakness and paralysis due to depolarization. From the side of the heart, both tachycardia and (more often) bradycardia can be noted.

The central effects of OPC poisoning are realized by dizziness, agitation, confusion, hypotension, respiratory depression, and coma. Death usually occurs due to respiratory failure.

What to do? What measures and in what sequence to carry out? According to WHO recommendations, "treatment should be started immediately." At the same time, assistance measures should be complete and comprehensive.

First of all, FOS should be removed from the injection site. FOS should be washed off the skin and mucous membranes with a 3-5% solution of SODIUM HYDROCARBONATE or simply with soap and water. In case of intoxication due to the ingestion of substances, it is necessary to wash the stomach, prescribe adsorbent and laxatives, use high siphon enemas. These activities are carried out repeatedly. If FOS has got into the blood, it is accelerated in the urine (forced diuresis). Effective use of HEMOSORPTION, hemodialysis and peritoneal dialysis.

The most important component of the treatment of acute OP poisoning is drug therapy. If overexcitation is observed during FOS poisoning M-cholinergic receptors, then it is logical to use antagonists - M-anticholinergics. First of all, it is necessary to inject ATROPIN in large doses (10-20-30 ml in total). Doses of atropine increase depending on the degree of intoxication. Monitor airway patency and, if necessary, intubate and artificial respiration. Guidelines for the additional administration of atropine are the state of respiration, convulsive reaction, blood pressure, pulse rate, salivation (salivation). The introduction of atropine at a dose of several hundred milligrams per day is described in the literature. In this case, the pulse rate should not exceed 120 beats per 1 minute.

In addition, in case of OPC poisoning, it is necessary to use specific antidotes - reactivators. acetylcholinesterase. The latter include a number of compounds containing an OXYME group (-NOH) in the molecule: dipyroxime is a quaternary amine, and isonitrosine is a tertiary amine; ( a mp., 15% - 1 ml). The reaction proceeds according to the scheme: AChE - P = NOH. Dipiroxime interacts with FOS residues associated with acetylcholinesterase releasing the enzyme. The phosphorus atom in AChE compounds is firmly bonded, but the bond P = NOH, that is, phosphorus with the oxime group, is even stronger. In this way, the enzyme is released and restores its physiological activity. But the action of reactivator cholinesterase does not develop quickly enough, so the most appropriate use of AChE reactivators, coupled with M-anticholinergics. Dipyroxine is prescribed parenterally (1-3 ml s / c and only in especially severe cases / in).

M-cholinomimeticshave a direct stimulating effect on Mholinoceptors. The standard of such substances is the alkaloid muscarine, which has a selective effect on M-cholinergic receptors. Muscarine is not a cure, but the poison contained in the fly agaric can cause acute poisoning.

Poisoning with muscarine gives the same clinical picture and pharmacological effects as AChE drugs. There is only one difference - here the action on M-receptors is direct. The same main symptoms are noted: diarrhea, shortness of breath, abdominal pain, salivation, pupil constriction (miosis - the circular muscle of the pupil contracts), intraocular pressure decreases, accommodation spasm is noted (near point of vision), confusion, convulsions, coma.

From M-cholinomimetics in medical practice the most widely used are: PILOCARINA HYDROCHLORIDE (Pilocarpini hydrochloridum) powder; eye drops 1-2% solution in vials of 5 and 10 ml, eye ointment - 1% and 2%, eye films containing 2.7 mg of pilocarpine), ACECLIDIN (Aceclidinum) - a mp. - 1 and 2 ml of 0.2% solution; 3% and 5% - eye ointment.

Pilocarpine is an alkaloid from the shrub Pilocarpus microphyllus, (South America). Currently obtained synthetically. Renders direct M-cholinomimetic action.

By stimulating effector organs receiving cholinergic innervation, M-cholinomimetics cause effects similar to those observed during irritation of the vegetative colinergic nerves. Particularly strongly increases pilocarpine secretion of glands. But pilocarpine, being a very strong and toxic drug, is used only in ophthalmic practice for glaucoma. In addition, pilocarpine is used for retinal vascular thrombosis. Used topically, in the form of eye drops (1-2% solution) and eye ointment (1 and 2%) and in the form of eye films. It constricts the pupil (from 3 to 24 hours) and reduces intraocular pressure. In addition, it causes a spasm of accommodation. The main difference from AChE drugs is that pilocarpine has a direct effect on M-cholinergic receptors eye muscles, and AChE means mediated.

Aceclidin (Aceclidinum) is a synthetic M-cholinomimetic of direct action. Less toxic. They are used for local and resorptive action, that is, they are used both in eye practice and in general exposure. Aceclidin is prescribed for glaucoma ( a little irritating to the conjunctiva), as well as for atomy of the gastrointestinal tract (in the postoperative period), bladder and uterus. With parenteral administration, there may be side effects: diarrhea, sweating, salivation. Contraindications: bronchial asthma, pregnancy, atherosclerosis.

MEANS BLOCKING M-CHOLINORECEPTORS (M-CHOLINOBLOCKERS, ATROPINE-LIKE DRUGS)

M-anticholinergics OR M-anticholinergics, drugs of the atropine group are drugs that block M-cholinergic receptors. Atropine is a typical and most well-studied representative of this group - hence the group is called atropine-like funds. M-anticholinergics block peripheral Mholinoreceptors located on the membrane of effector cells at the endings postganglionic cholinergic fibers, that is, they block PARASYMPATIC, cholinergic innervation. Blocking predominantly muscarinic effects of acetylcholine, the effect of atropine on the autonomic ganglia and neuromuscular synapses does not apply.

Majority atropine-like blocking funds M-cholinergic receptors in the CNS.

M-anticholinergicwith high selectivity of action is Atropine (Atropini sulfas; tablets 0.0005; ampoules 0.1% - 1 ml; 1% eye ointment).

Atropine is an alkaloid found in plants of the nightshade family. Atropine and related alkaloids are found in a number of plants:

Beauty (Atropa belladonna); - henbane ( Hyoscyamus niger); - Datura (Datura stramonium).

Atropine is currently obtained synthetically, that is, by chemical means. The name Atropa Belladonna is paradoxical, since the term "Atropos" means "three fates leading to an inglorious end to life", and "Belladonna" - "charming woman" (donna - woman, Bella - woman's name in Romance languages). This term is due to the fact that the extract from this plant, instilled into the eyes by the beauties of the Venetian court, gave them a "radiance" - dilated pupils.

The mechanism of action of atropine and other drugs of this group is that, by blocking M-cholinergic receptors, competing with acetylcholine, they prevent the mediator from interacting with them.

The drugs do not affect the synthesis, release and hydrolysis of acetylcholine. Acetylcholine is released, but does not interact with receptors, since atropine has a greater affinity (affinity) for the receptor. Atropine like everyone else M-anticholinergics, reduces or eliminates the effects of irritation of cholinergic (parasympathetic) nerves and the action of substances with M-cholinomimetic activity (acetylcholine and its analogues, AChE agents, M-cholinomimetics). In particular, atropine reduces the effects of irritation n. vagus. Antagonism between acetylcholine and atropine is competitive, therefore, with an increase in the concentration of acetylcholine, the action of atropine at the point of application of muscarine is eliminated.

MAIN PHARMACOLOGICAL EFFECTS OF ATROPINE

1. Antispasmodic properties are especially pronounced in atropine. By blocking M-cholinergic receptors, atropine eliminates the stimulating effect of parasympathetic nerves on smooth muscle organs. The tone of the muscles of the gastrointestinal tract, bile ducts and gallbladder, bronchi, ureters, and bladder decreases.

2. Atropine also affects the tone of the muscles of the eye. Let's analyze the effects of atropine on the eye:

a) with the introduction of atropine, especially when it is applied topically, due to a block M-cholinergic receptors circular muscle of the iris, pupil dilation is noted - mydriasis. Mydriasis also increases as a result of the preservation of the sympathetic innervation of m. dilatator pupillae. Therefore, atropine on the eye in this regard acts for a long time - up to 7 days;

b) under the influence of atropine, the ciliary muscle loses its tone, it flattens, which is accompanied by tension of the zinn ligament that supports the lens. As a result, the lens also flattens, and the focal length of such a lens lengthens. The lens sets vision to a far point of vision, so nearby objects are not clearly perceived by the patient. Since the sphincter is in a state of paralysis, it is not able to narrow the pupil when looking at nearby objects, and photophobia (photophobia) occurs in bright light. This condition is called ACCOMMODATION PARALYSIS or CYCLOPLEGIA. Thus, atropine is both MIDRATIC and CYCLOPLEGIC. Topical application of a 1% solution of atropine causes a maximum mydriatic effect within 30-40 minutes, and full recovery of function occurs on average after 3-4 days (sometimes up to 7-10 days). Accommodation paralysis occurs after 1-3 hours and lasts up to 8-12 days (approximately 7 days);

c) relaxation of the ciliary muscle and displacement of the lens into the anterior chamber of the eye is accompanied by a violation of the outflow of intraocular fluid from the anterior chamber. In this regard, atropine either does not change intraocular pressure in healthy individuals, or in individuals with a shallow anterior chamber and in patients with narrow-angle glaucoma, it may even increase, that is, lead to an exacerbation of an attack of glaucoma.

INDICATIONS FOR ATROPINE IN OPHTHALMOLOGY

1) In ophthalmology, atropine is used as a mydriatic in order to cause cycloplegia (accommodation paralysis). Mydriasis is necessary in the study of the fundus and in the treatment of patients with iritis, iridocyclitis and keratitis. In the latter case, atropine is used as an immobilization agent that promotes functional rest of the eye.

2) To determine the true refractive power of the lens when selecting glasses.

3) Atropine is the drug of choice if it is necessary to obtain maximum cycloplegia (accommodation paralysis), for example, in the correction of accommodative strabismus.

3. EFFECT OF ATROPINE ON ORGANS WITH SMOOTH MUSCLES. Atropine reduces the tone and motor activity (peristalsis) of all parts of the gastrointestinal tract. Atropine also reduces the peristalsis of the ureters and the bottom of the bladder. In addition, atropine relaxes the smooth muscles of the bronchi and bronchioles. In relation to the biliary tract, the antispasmodic effect of atropine is weak. It should be emphasized that the antispasmodic effect of atropine is especially pronounced against the background of the previous spasm. Thus, atropine has an antispasmodic effect, that is, atropine acts in this case as an antispasmodic. And only in this sense can atropine act as an "anesthetic" agent.

4. INFLUENCE OF ATROPINE ON THE GLANDS OF INTERNAL SECRETION. Atropine sharply weakens the secretion of all external secretion glands, with the exception of the mammary glands. In this case, atropine blocks the secretion of liquid watery saliva, caused by stimulation of the parasympathetic division of the autonomic nervous system, dry mouth occurs. Decreased lacrimation. Atropine reduces the volume and total acidity of gastric juice. In this case, oppression, weakening of the secretion of these glands can be up to their complete shutdown. Atropine reduces the secretory function of the glands in the cavities of the nose, mouth, pharynx and bronchi. The secret of the bronchial glands becomes viscous. Atropine, even in small doses, inhibits the secretion of sweat glands.

5. EFFECT OF ATROPINE ON CARDIOVASCULAR SYSTEM. Atropine, bringing the heart out of control n. vagus, causes TACHICARDIA, that is, increases the heart rate. In addition, atropine facilitates the conduction of an impulse in the conduction system of the heart, in particular in the AV node and along the atrioventricular bundle as a whole. These effects are not very pronounced in the elderly, since in therapeutic doses atropine does not have a significant effect on peripheral blood vessels, they have a reduced tone n. vagus. Atropine has no significant effect on blood vessels in therapeutic doses.

6. EFFECT OF ATROPINE ON THE CNS. In therapeutic doses, atropine does not affect the central nervous system. In toxic doses, atropine sharply excites the neurons of the cerebral cortex, causing motor and speech excitation, reaching mania, delirium and hallucinations. There is a so-called "atropine psychosis", leading further to a decrease in functions and the development of coma. It also has a stimulating effect on the respiratory center, but with increasing doses, respiratory depression may occur.

INDICATIONS FOR THE USE OF ATROPINE (except ophthalmic)

1) As an ambulance for:

a) intestinal b) renal, c) hepatic colic.

2) With spasms of the bronchi (see adrenomimetics).

3) In the complex therapy of patients with gastric ulcer and duodenal ulcer (reduces the tone and secretion of the glands). It is used only in a complex of therapeutic measures, since it reduces secretion only in large doses.

4) Atropine is widely used as a means of pre-needication in anesthetic practice before surgery. Atropine is used as a means of preparing a patient for surgery because it has the ability to suppress the secretion of the salivary, nasopharyngeal and tracheobronchial glands.

As you know, many anesthetics (ether in particular) are strong mucosal irritants. In addition, by blocking M-cholinergic receptors heart (the so-called vagolytic action), atropine prevents negative reflexes on the heart, including the possibility of its reflex stop.

Using atropine and reducing the secretion of these glands, the development of inflammatory postoperative complications in the lungs is prevented. This explains the significance of the fact that resuscitation doctors attach when they talk about the full-fledged opportunity to "breathe" the patient.

5) Atropine is used in cardiology. M-anticholinergic its effect on the heart is favorable in some forms of cardiac arrhythmias (for example, atrioventricular block of vagal origin, that is, with bradycardia and heart blockade).

6) Atropine has found wide application as an ambulance for poisoning:

a) AChE means (FOS)

b) M-cholinomimetics(muscarine).

Along with atropine, other well-known atropine-like drugs. to natural atropine-like alkaloids include SCOPOLAMINE (hyoscine) Scopolominum hydrobromidum. Available in ampoules of 1 ml - 0.05%, as well as in the form of eye drops (0.25%). It is found in the mandrake plant (Scopolia carniolica) and in the same plants that contain atropine (Belladonna, Henbane, Datura). Structurally close to atropine. Has pronounced M-anticholinergic properties. There is only one significant difference from atropine: in therapeutic doses, scopolamine causes mild sedation, CNS depression, sweating and sleep. It acts depressingly on the extrapyramidal system and the transfer of excitation from the pyramidal pathways to the motor neurons of the brain. The introduction of the drug into the cavity of the conjunctiva causes less lengthy mydriasis.

Therefore, anesthesiologists use scopolamine (0.3-0.6 mg s / c) as a means of premedication, but usually in combination with morphine (but not in the elderly, as it can give confusion). It is sometimes used in psychiatric practice as a sedative, and in neurology for the correction of parkinsonism. Scopolamine acts shorter than atropine. It is also used as an antiemetic and sedative for sea and air sickness (Aeron tablets are a combination of scopolamine and hyoscyamine).

The group of alkaloids obtained from plant materials (rhomboid ragwort) also includes PLATIFILLIN. (Platyphyllini hydrotartras: tablets of 0.005, as well as ampoules of 1 ml - 0.2%; eye drops - 1-2% solution). It acts about the same, causing similar pharmacological effects, but weaker than atropine. It has a moderate ganglioblocking effect, as well as a direct myotropic antispasmodic Effect ( papaverine-like), as well as on the vasomotor centers. It has a calming effect on the central nervous system. Platifillin is used as an antispasmodic for spasms of the gastrointestinal tract, bile ducts, gallbladder, ureters, with increased tone of the cerebral and coronary vessels, as well as for the relief of bronchial asthma. In ophthalmic practice, the drug is used to dilate the pupil (acts shorter than atropine, does not affect accommodation). It is injected under the skin, but it should be remembered that solutions of 0.2% concentration (pH = 3.6) are painful.

For ophthalmic practice, HOMATROPIN is proposed (Homatropinum: 5 ml vials - 0.25%). It causes pupil dilation and accommodation paralysis, that is, it acts as a mydriatic and cycloplegic. The ophthalmic effects caused by homatropine last only 15-24 hours, which is much more convenient for the patient compared to the situation when atropine is used. The risk of IOP rise is less, because it is weaker than atropine, but at the same time, the drug is contraindicated in glaucoma. Otherwise, it does not fundamentally differ from atropine, it is used only in eye practice.

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No. 4 [Annals of Surgery, 2018]

Founded in 1996. A multidisciplinary journal that publishes modern achievements in almost all sections of surgical specialties, including general and private surgery, issues of teaching history, as well as information about the largest scientific and practical centers of domestic and foreign surgery. The regular headings of the journal are: Science centers and schools", "Reviews", "Lectures", "Archives of surgery", "How it's done", "New surgical technologies", " Young specialist"," History of surgery.

neostigmine) - a drug that reversibly blocks the enzyme acetylcholinesterase, as a result of which hydrolysis stops<...>acetylcholine and increased cholinergic transmission.<...>the parasympathetic nervous system produces the opposite effect: its stimuli promote the release of acetylcholine<...>a drug that reversibly binds to acetylcholinesterase molecules, as a result of which hydrolysis stops<...>acetylcholine and increased cholinergic transmission.

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Glossary of terms and concepts in organic and biological chemistry

FSBEI HPE Orenburg State Agrarian University

The manual presents concepts that reveal the main issues studied in the course of organic and biological chemistry. The manual can be used to test the knowledge of students and self-learning the course. The reference manual is intended for students of higher educational institutions studying the course of organic and biological chemistry in full-time and part-time forms of education.

Acetylcholine is a neurotransmitter that is an ester of choline and acetic acid.<...>Acetylcholinesterase is an enzyme of the hydrolase class (EC 3.1.1.7), catalyzing the reaction of cleavage of the acetylcholine molecule<...>with the formation of choline and acetic acid; hydrolysis of acetylcholine is necessary for the transmission of nervous excitation<...>trimethylaminoethyl alcohol, present in the composition of phosphatidylcholine, plasmalogens, sphingomyelin, acetylcholine<...>Choline acetyltransferase is an enzyme of the transferase class (EC 2.3.1.6), catalyzing the formation of acetylcholine

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№2 [Biological membranes: Journal of membrane and cell biology, 2018]

Publishes articles and reviews covering various, primarily physicochemical, aspects of membrane and cell biology. These include: the structure of membranes, their lipid composition and physicochemical properties, as well as the structure membrane proteins. Special attention is given to bioenergetics, membrane transport, processes of reception and regulation, which are responsible for the transfer of information. A significant place is given to works devoted to the study of intercellular contacts and interactions, as well as the structure and function of intracellular membrane formations. The journal publishes fundamental research of a biomedical nature, including those devoted to membrane aspects of immunology. The journal is intended for specialists, young researchers and senior students working in the field of biophysics, biochemistry and cell biology.

» BIOLOGICAL MEMBRANES, 2018, volume 35, no. 2, p. 143–149 143 INTRODUCTION Presence of hydrolysis enzyme in cells<...>Cholinesterase inhibitors prozerin, ezerin and berberine completely blocked the hydrolysis of acetylcholine by cells.<...>plant cholinesterases were used and the red analogue of Ellman's reagent (DFOX), which, after hydrolysis<...>It follows from this that cholinesterases, catalyzing the hydrolysis of choline ester, eliminate acetylcholine, leveling<...>Thus, inhibition of cholinesterase results in a lack of hydrolysis of acetylcholine, which increases

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Biochemistry textbook. manual for graduate students of the direction of training 06.06.01 Biologist. science

The textbook presents scientific information on the study of the main sections of the discipline "Biochemistry", indicating questions for intermediate and final control.

Acetylcholine receptors located on the cell membrane can be cited as the most studied.<...>These proteins specifically interact with acetylcholine CH3C(O) - OCH2CH2N + (CH3)3 and respond to this by transferring<...> <...>For example, amidases accelerate the hydrolysis of acid amides.<...>Urease accelerates the hydrolysis of urea to NH3 and CO2.

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Ecological toxicology studies. allowance

Rostov

The textbook discusses the basic concepts, historical aspects of formation and development, the goals and objectives of modern environmental toxicology, the mechanisms and characteristics of the toxic effects of chemical pollutants on populations of organisms and biocenoses that are part of ecological systems. Data on the sources and behavior of xenobiotics and other ecopollutants in environment, their drift, accumulation, bioconcentration, transformation, detoxification and excretion in various biological systems; about reactions to the impact of priority ecotoxicants at the population level. Approaches to assessing the toxicity of ecopollutants are outlined, and the principles of ecotoxicological regulation are considered.

which depends on the intensity of the light flux and the ability to absorb it by the substance), hydrolysis<...>transformations are provided by various enzymatic systems (enzymes) that implement the processes of oxidation, hydrolysis<...>air occurs due to precipitation, diffusion in the boundary layer and chemical degradation processes (hydrolysis<...>The activity of hydrolysis and oxidation processes directly correlates with the intensity of exposure to solar<...>acetylcholine - one of the neurotransmitters (neurotransmitters) during the transmission of a nerve impulse in synapses

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Toxicology with the basics of ecotoxicology studies. allowance

The manual contains basic knowledge of general toxicology, industrial toxicology and environmental toxicology. The main classifications of toxic substances, the mechanisms of their action on the human body, addiction and combined action of poisons, toxicokinetics and toxicodynamics, the biological characteristics of the body with a toxic effect, the toxicological characteristics of the main industrial poisons, the main directions for the prevention of occupational poisoning, the basics of ecological toxicology are presented.

<...>This is exactly what AChE does, instantly hydrolyzing ACh, the mediator.<...>Light accelerates hydrolysis and oxidation.<...>Hydrolysis. Water, especially when heated, quickly destroys many substances.<...>The rate of hydrolysis strongly depends on the pH of the medium.

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Free radical processes and the state of membranes during hypothermia [monograph]

Rostov

The monograph systematizes and summarizes current literature data and a large amount of experimental material on the effect of hypothermia on the structural and functional state of membranes during hypothermia of various depths and durations. Results on the role of oxidative stress in membrane damage during hypothermia are presented. Much attention is paid to the oxidative modification of proteins as one of the specific and reliable markers in free radical pathology. The features of free radical processes in the nervous tissue and blood are covered in detail. Data are presented on the effect of hypothermia on membrane-bound enzymes and the structural-dynamic state of membranes. An analysis of the mechanisms of the protective action of the opioid peptide dalargin is given.

difficult over the air communications acetylcholine; b) an anionic locus that binds the quaternary nitrogen atom of acetylcholine<...>acetylcholine, the so-called "back door" - "back door".<...>Enzymatic hydrolysis of acetylcholine depends on many factors: substrate concentration, temperature<...>At the same time, phosphatidylserine did not contribute to an increase in the rate of hydrolysis of acetylcholine, possibly due to<...>acetylcholine and the maximum rate of the enzyme.

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Science - agricultural production. Issue 3(3)

The collection includes materials from scientists of the Research Technological Institute of Animal Husbandry of the Central Chernozem Zone, working in the field of breeding, feeding, physiology, zoohygiene, veterinary medicine and economics Agriculture on the application of new research methods in industrial animal husbandry

/ which undergoes the exchange and transformation of acetylcholine itself.<...>acetylcholine and ensure restoration of nerve impulse conduction.<...>REZNYCHENKO Candidate of Biological Sciences ‘(N I I Zh Forest-steppe and Polissya of the Ukrainian SSR) Acetylcholine-chloride hydrolysis reaction<...>The reagent control is 3 ml of reagent no. 3 (without acetylcholine) mixed with 2 ml of water.<...>acids released during hydrolysis, received from the blood and synthesized, in the cell.

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STUDY OF CHOLINESTERASE IN EXPERIMENTAL KERATITIS ABSTRACT DIS. ... CANDIDATE OF BIOLOGICAL SCIENCES

ODESSA STATE UNIVERSITY

The present study was undertaken to study the violations of enzymatic processes in inflammatory diseases of the cornea.

We can only point to indirect data confirming the relationship between the content of acetylcholine in tissue<...>The essence of the method lies in the fact that the acetic acid formed during the enzymatic hydrolysis of acetylcholine<...>Data for brain tissues showed a very small (about 9-8%) decrease in the rate of acetylcholine hydrolysis.<...>activation of the reaction catalyzed by it, i.e., the amount of energy required for the course of the hydrolysis reaction<...>acetylcholine.

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Biochemistry textbook. allowance

Under alkaline hydrolysis, casein breaks down into protein and phosphoric acid.<...> <...>It turned out that this inhibitor has a close structural similarity to acetylcholine and interacts similarly to it.<...>Table 1 Hydrolysis of starch by α-amylase of saliva Name of the substrate and products of its hydrolysis Color at<...>reactions with iodine Time taken for hydrolysis Temperature conditions for hydrolysis Trommer reaction 5.3

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The role of the method is discussed quantum mechanics– molecular mechanics (KM/MM) for modeling chemical transformations in the active centers of cholinesterases. Various variants of the KM/MM method were used to study the molecular mechanisms of the reactivation reaction of butyrylcholinesterase phosphorylated at the catalytic serine residue.

<...>The catalytic mechanism of hydrolysis of AChE and BChE substrates related to serine hydrolases is fundamentally<...>intermediate during the nucleophilic attack of the catalytic water molecule, the products of the hydrolysis reaction are released<...>also energy profile for the full cycle of chemical transformations in the active site of AChE during hydrolysis<...>acetylcholine by the KM/MM method were first described in .

No. 4 [Fine chemical technologies, 2009]

The journal "Fine Chemical Technologies" (former name "Bulletin of MITHT") is published once every two months and publishes reviews and articles on topical problems of chemical technology and related sciences. The magazine was founded in 2006. The founder of the journal is the Moscow State Academy of Fine Chemical Technology. M.V. Lomonosov (MITHT), now Moscow State University fine chemical technologies named after M.V. Lomonosov. The journal is included in the List of leading peer-reviewed scientific journals, in which the main scientific results of the dissertation for the degree of doctor (candidate) of sciences should be published. The journal is abstracted in the international database Chemical Abstracts and is included in the international catalog of periodicals Ulrich. Under the new name "Fine Chemical Technologies", the journal "Vestnik MITHT" is published starting from the 1st issue of the 10th volume for 2015.

silica gel 7 Phosphatic acid Egg phosphatidylcholine 2-4 Derived from egg phosphatidylcholine by its hydrolysis<...>So, phosphatidylinositol diphosphate under the action of phospholipase C is hydrolyzed to 4-5 nm Phospholipids and proteins<...>An example of such an "anchored" protein is acetylcholinesterase, which catalyzes the hydrolysis of acetylcholine in the synaptic<...>With the participation of phospholipase C, which hydrolyzes membrane phospholipids, phospholipids can be modified<...>We accept that SiHCl3, SiCl4 and SiH2Cl2 are completely hydrolyzed by an alkaline solution during gas cleaning

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In experiments on mature male (♂) and female (♀) rats, the effect of gonadectomy and hormone replacement therapy on the content and intensity of enzymatic hydrolysis of acetylcholine (ACh) in the atrial and ventricular myocardium during the development of adrenaline damage to the myocardium was studied against the background of the use of a nitric oxide synthesis precursor L-arginine (600 mg/kg). It was found that the removal of the gonads reduces the ability of L-arginine to influence the metabolism of ACh in the myocardium of the atria and ventricles of the heart damaged by adrenaline, which is more pronounced in male rats. The use of sex hormone replacement therapy has the best positive effect on restoring the regularity of the dynamics of the content and activity of ACh hydrolysis in the myocardium when it is damaged against the background of L-arginine in the heart of males, which indicates a better sensitivity of the body of these animals to the use of corrective action, and a greater dependence of the effects of L -arginine from androgen balance.

<...>has the best positive effect on the restoration of the regularity of the dynamics of the content and activity of hydrolysis<...> <...> <...>Influence of gonadectomy on the activity of mediator hydrolysis in experimental conditions showed difference

A biochemical study of the activity of serum cholinesterase in workers of an industrial enterprise was carried out using the example of petrochemical production. The indicators of the average activity of the enzyme and the prevalence of indicators that go beyond the reference values were analyzed, depending on the work experience in the workplace, profession and diseases identified in workers. The main diseases, occupational and experience groups, in which cholinesterase activity significantly changes, have been established. The influence of experience and profession on the level of enzyme activity in blood serum is shown.

Cholinesterases (ChEs) are a family of hydrolase enzymes carboxylic acids, which catalyze the hydrolysis reaction<...>

EXCITATION TRANSFER IN SYMPATIC GANGLIA AT DIFFERENT GLYCEMIA ABSTRACT DIS. ... CANDIDATE OF BIOLOGICAL SCIENCES

LENINGRAD ORDER OF V. I. LENIN STATE UNIVERSITY NAMED AFTER A. A. ZHDANOV

In acute experiments on spinal and anesthetized cats, a clear dependence of the bioelectrical activity of the sympathetic section of the nervous system on the content of sugar in the blood was found.

Belitsky* 1959; Grob, 1961), on the synthesis of acetylcholine (Feldberg, 1945, 1950) and its destruction by cholinesterase<...>conduction of myelin-free presyaptic endings, * with a violation of normal formation, release and hydrolysis<...>Under these conditions, the reaction of ganglia to a standard dose of acetylcholine did not differ much from the norm.<...>enhanced the effect of acetylcholine.<...>administration of glucose (20 μg) acetylcholine had a pronounced effect.

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ON THE ROLE OF EXTRACELLULAR ANIONS AT REST AND DURING EXCITATION OF NERVE AND MUSCLE CELLS ABSTRACT DIS. ... CANDIDATE OF BIOLOGICAL SCIENCES

Moscow: INSTITUTE OF BIOLOGICAL PHYSICS OF THE USSR ACADEMY OF SCIENCES

CONCLUSIONS 1. In crustacean muscle fibers, the replacement of C1 iots and the surrounding solution with Br, NO2, and J does not affect the resting potential, which is on average 85 + - 1 mV. Replacing C1 ions with "non-penetrating" anions causes a rapid drop in the resting potential, followed by restoration of the previous level. The replacement of C1 ions by all anions studied by us has little effect on the amplitude and rate of rise of the action potential. The speed of the falling part of the DP in solutions with Br, NO s - and J - increases, and in solutions of salts of sulfate and acetate ions - significantly decreases. These data allow us to conclude that in the muscle fibers of crustaceans, as well as in vertebrates, C1- ions are normally involved in maintaining the resting potential and in the repolarization of the membrane after the action potential...

Agency Kniga-Service "by a method based on determining the amount of acetic acid released during hydrolysis<...>acetylcholine. using continuous potentiometric titration with sodium hydroxide solution (Elshshor<...>Thus, the action of anions is not carried out through the acetylcholine-cholinesterase system.<...>anions causes a change in the magnitude of the tonic contraction of the rectus abdominis muscle of the frog under the action of acetylcholine

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ANTIOXIDANT ACTIVITY OF NERVE FIBER LIPIDS DURING EXCITATION ABSTRACT DIS. ... CANDIDATE OF BIOLOGICAL SCIENCES

M.: MOSCOW ORDER OF LENIN AND THE ORDER OF LABOR RED BANNER STATE UNIVERSITY NAMED AFTER M. V. LOMONOSOV FACULTY OF BIOLOGY AND SOIL

The aim of our work was to study the role and participation of the lipid fraction of the nerve fiber in the free radical process that occurs during excitation, to study one of the most important physicochemical characteristics of lipids - their antioxidant activity (AOA) under conditions of normal conduction, under conditions of reduced lability, and also at the holding block.

choline can occur both due to the breakdown and resynthesis of phosphatidylcholine, and due to enzymatic hydrolysis<...>acetylcholine (Nachmansohn, 1969).<...>An increase in the content of choline can occur both due to the enzymatic hydrolysis of acetylcholine

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CHLORINATED TERPENE CHLORPINAC AS AN ACARICIDE ABSTRACT DIS. ... CANDIDATE OF BIOLOGICAL SCIENCES

LENINGRAD VETERINARY INSTITUTE

Purpose - to study the new acaricide chlorpinac, its physicochemical properties, toxicity to warm-blooded animals, routes of penetration, deposition and release of the drug from the body of animals.

In the presence of cholinesterase in the homogenate, this enzyme was supposed to destroy acetylcholine, and in the absence of<...>cholinesterase in a homogeneous mass, acetylcholine added to it should have remained unchanged<...>The rectus abdominis muscle of the frog was used as a biological indicator for acetylcholine in connection with<...>determining the concentration of chlorpinac, which would inhibit cholinesterase by 50%, i.e., increase the hydrolysis time<...>acetylcholine twice in comparison with the control, a series of experiments was carried out.

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No. 4 [Advances in physiological sciences, 2018]

Materials of a review-critical nature are published on various branches of physiology, as well as articles in which the authors, on the basis of the available scientific literature, present original concepts on fundamental theoretical issues, argued by their own experimental material. The journal "Uspekhi Physiologicheskikh Nauk" is intended for teachers and physiologists and biophysicists of medical and general biological profile.

One of the methods of AD therapy is to increase the level of acetylcholine in the brain.<...>These drugs prolong the action of the neurotransmitter acetylcholine in the synaptic cleft, which leads to<...>Acetylcholinesterase is an enzyme that catalyzes the hydrolysis of acetylcholine and causes it<...>Galantamine increases the concentration of acetylcholine not only by inhibiting AChE, but also by increasing the activity<...>Gliatilin is a physiological precursor of acetylcholine, which makes it an interesting target.

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PRODUCTS OF OXIDATIVE DEAMINATION OF MONOAMINES AS BLOCKERS OF CRUSHING DIVISIONS ABSTRACT DIS. ... CANDIDATE OF BIOLOGICAL SCIENCES

Moscow: ACADEMY OF SCIENCES OF THE USSR INSTITUTE OF DEVELOPMENTAL BIOLOGY

task given work there were searches for specific methods of switching off individual mediators or individual functions of one mediator.

embryogenesis, we used the method of enzymatic inactivation of these substances. As a source of an enzyme that hydrolyzes<...>acetylcholine, we used a number of preparations containing highly active cholinesterase.<...>Acetylcholine and mcholyl, hydrolyzed by EChE, for the most part had no protective effect.<...>The basis of this action is most likely the hydrolysis of endogenous acetylcholine. * This hydrolysis can lead to<...>In the second case, unfertilized eggs were exposed for 30-40 minutes. with hydrolysis of volume C 1 protein of chlorella

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Medico-biological bases of life safety studies. allowance

Outlined theoretical basis physiological mechanisms of the body that ensure the interaction of a person with the environment and the production environment, the principles and levels of the processes of self-regulation of the body. The medical and biological characteristics of negative physical and chemical environmental factors, as well as the processes of adaptation and self-regulation under the influence of these factors, are given. In addition, the manual considers first aid for life-threatening conditions of the body. The manual was written in accordance with the program for training students in the Biomedical Fundamentals of Life Safety, compiled on the basis of the State General Educational Standard of Higher vocational education. It can be used by students of environmental and technical specialties and anyone interested in biomedical problems of life safety.

excitation under the influence of a nerve impulse in the synapse are formed chemically active substances mediators (acetylcholine<...>Acetylcholinesterase catalyzes the hydrolysis of acetylcholine (ACh), a chemical transmitter (transmitter) of the nerve<...>This is exactly what AChE does, instantly hydrolyzing the ACh mediator.<...>(especially obese) highly active biological substances are released from them (histamine, serotonin, acetylcholine<...>Elements of the 3rd group are prone to both hydrolysis and complex formation.

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Biochemistry and Molecular Biology: Textbook

This guide includes summary basic theoretical information of plant biochemistry, a guide to laboratory exercises, assignments for independent work and tests that allow you to control the degree of assimilation of the material by students. It is assumed that students will independently study various issues of plant biochemistry in more depth, present them in the form of messages and presentations, using modern information technologies.

This is done by a special enzyme acetylcholinesterase, which catalyzes the hydrolysis of acetylcholine to acetate.<...>acetylcholine to choline and acetic acid.<...>mainly hydrolysis of acetylcholine (R=CH3).<...>Acetylcholine is the acetate ester of choline.<...>acetylcholine : acetylcholine + H2O → choline + acetic acid Write the complete equation for this reaction. No.

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Professional multidisciplinary journal for practicing physicians. Articles in the journal combine practical information, clinical lectures and scientific reviews with medical news. Each issue presents the main thematic sections on specialties: therapy, pediatrics, allergology, bronchopulmonary, gastroenterology, gynecology, dermatovenereology, cardiology, psychoneurology, rheumatology, urology; information on professional development from the best medical universities in the country; news, interviews and a page for the publication of dissertation works.

more and more evidence that insulin is involved in the production of a number of neurotransmitters, in particular acetylcholine<...>Insulin resistance and supra-optimal insulin levels contribute to lower acetylcholine levels.<...>Acetylcholine is also major in the function of insulin-secreting pancreatic β-cells.<...>Due to this, the hydrolysis of acetylcholine in the synaptic cleft decreases and its action is prolonged.<...>position after it was found that the use of drugs designed to compensate for the level of acetylcholine

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Theoretical foundations of biochemistry textbook. allowance

The textbook on biochemistry is distinguished by a clear and accessible presentation of the main and chemical structure the most important substances of the body, established the relationship between the chemical transformations of substances in the body and their biological functions. The purpose of the textbook is to form students' understanding of fundamental achievements in the study of the biochemical foundations of life and development.

Copyright JSC "Central Design Bureau "BIBCOM" & LLC "Agency Kniga-Service"<...>These proteins specifically interact with acetylcholine CH3C(O) - OCH2CH2N+(CH3)3 and respond to this by transferring<...>For this, a special enzyme is used - acetylcholinesterase, which catalyzes the hydrolysis of acetylcholine to acetate.<...>In the course of hydrolysis, ester bonds 1 and 3 are rapidly hydrolyzed in the first stages, and then slowly<...>hydrolysis of 2 monoacylglycerol.

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Environmental Toxicology: Guidelines Guidelines

Intended for students of the Faculty of Biology and Ecology, studying in the specialty 013100 Ecology (discipline "Ecological Toxicology", block of general education), full-time education. Tab. 3.

means "sweet, sugar, glucose") complex organic compounds such as esters that break down during hydrolysis<...> <...>acetylcholine by cholinesterase (ChE) enzymes.<...>undergoing hydrolysis, as a result of which the active centers of ChE are released for new reactions with acetylcholine<...>

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Biotesting and water toxicology method. instructions

Designed for students studying in the direction 020400.62 Biology (discipline "Biotesting and water toxicology", BZ cycle), full-time education.

These processes are realized within a fraction of a millisecond, their discontinuity is due to rapid hydrolysis<...>acetylcholine by the enzyme cholinesterase (ChE). When ChE and acetylcholine interact, acetylated<...>enzyme - a fragile compound that quickly undergoes hydrolysis, as a result of which the active centers of ChE<...>released for new reactions with acetylcholine.<...>When ChE interacts with FOV, a hydrolysis-resistant phosphorylated enzyme is formed, which is unable to

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Vocabularium (dictionary-reference book) studies. allowance

Rostov

The textbook "Vocabularium" (dictionary-reference book) is intended for students studying related subjects: chemistry of natural compounds, bioorganic chemistry, biophysical chemistry, nutritional chemistry and a complex of pharmacological disciplines. Focusing on a wide range of readers' interests, the author used commonly used terms found in the texts of books in these areas. Definitions and interpretations were taken from various sources published at different times, paraphrasing was undertaken only for the sake of greater completeness and clarity of the definition. The amount of information is not the same, as well as the capacity of definitions, nevertheless, the phraseology of the explanatory text in the book is in strict accordance with the stable turns of speech that have developed in science.

Acetylcholine (correctly - acetylcholine hydroxide, see choline) - Quaternary ammonium base, chemically<...>Acetylcholine is a chemical transmitter of nervous excitation in cholinergic synapses.<...>Acetylcholinesterase 3.1.1.7 (acetylcholine - acetylhydrolase) is an enzyme of the hydrolase class that catalyzes<...>hydrolysis of acetylcholine, as well as other choline esters, for example: Copyright OJSC Central Design Bureau BIBCOM & LLC Agency<...>there is an excessive accumulation of acetylcholine in the nerve cell, which leads to blocking of the transmission of nerve

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Ecological problems of unique natural and anthropogenic landscapes Vseross. scientific-practical. conference, November 29, 2007

The collection contains materials of the All-Russian scientific and practical conference on topical issues of specially protected natural areas. The focus is on the following issues: natural complexes and animal world protected areas; geological monuments of nature; environmental problems and public health; natural and anthropogenic environmental factors and monitoring problems. The materials are published in the author's edition.

There are two main types of CEZ: acetylcholinesterase (acetylcholine acetylhydrolase, AChE; E.F. 3.1.1.7)<...>AChE is a specialized enzyme and its main physiological function is the hydrolysis of acetylcholine (ACh), a mediator<...>An exception is kII for DDVP during the hydrolysis of PrTX and ButCh.<...>It is known that if different substrates are hydrolyzed by one enzyme, then the rate of inhibition of their hydrolysis by the inhibitor<...>The hydrolysis of MeX is not inhibited by its excess.

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Pharmacology textbook for dentist students. faculties

Moscow: Laboratory of Knowledge

The textbook "Pharmacology" for the dental faculties of medical universities was written by teachers of the Department of Pharmacology of the Institute of Pharmacy and Translational Medicine of the First Moscow State Medical University. I. M. Sechenov. The content of the textbook is fully consistent with the program of the course being studied. The book introduces the reader to the subject and tasks of pharmacology, sources of obtaining and stages of creation medicines, the principles of their classification, the basics of pharmacokinetics and pharmacodynamics. The section of private pharmacology contains information about the drugs of the main pharmacological groups. Particular attention is paid to drugs used in dentistry. The appendix contains modern prescription forms and rules for prescribing medicines.

<...>Takes part in the synthesis of acetylcholine, blocks cholinesterase, thereby increasing the level of acetylcholine<...>Like trypsin, it hydrolyzes proteins and peptones to form peptides.<...>Drugs that reduce the release of acetylcholine Botulinum toxin type A prevents the release of acetylcholine<...>Takes part in the synthesis of acetylcholine, blocks cholinesterase, thereby increasing the level of acetylcholine

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Fundamentals of ecotoxicology studies. allowance

Publishing House Orel GAU

The textbook discusses the basic concepts of ecotoxicology, presents the parameters of toxicometry and toxicokinstikn, describes the main patterns of processes and phenomena associated with sources of toxicants entering the environment. Considerable attention is paid to the patterns of migration of toxicants in agroecosystems, the behavioral characteristics and significance for natural environments and living organisms of toxicants of a chemical, physical and biological nature.

By imitating part of acetylcholine, they interact with the enzyme and turn off its action on long term <...>In the liver, pyrethroids undergo oxidation and hydrolysis to form glucuronates.<...>acetylcholine - a chemical transmitter of nervous excitation.<...>Hydrolysis of pesticides takes place with the participation of water.<...>There are the following ways of non-biotic decomposition of pesticides: 1) Decomposition by hydrolysis, especially

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No. 1-special issue [Emergency Medicine, 2019]

The subject of the journal is information and analytical in the field of clinical, industrial, aerospace, marine and sports medicine, as well as specialized sanitary and epidemiological surveillance and medical and sanitary support for employees of organizations in certain industries with especially dangerous working conditions and residents of certain territories. The journal publishes scientific articles, scientific reviews, lectures, cases from clinical practice, brief reports in these areas, comments and appeals of the editorial board, annotations of thematic foreign and domestic publications, the main scientific results of dissertations for the degree of candidate of science, for the degree doctors of sciences, scientific reviews and reviews, reports on congresses, symposiums, conferences and other scientific and practical events, guidelines, normative and legal documents. The authors of scientific articles of the journal are leading scientists and specialists in the field of clinical, industrial, aerospace, marine and sports medicine, as well as specialized sanitary and epidemiological surveillance and medical and sanitary support for employees of organizations in certain industries with especially dangerous working conditions, and residents of certain territories, graduate students, applicants, doctoral students, as well as doctors and specialists of the Federal Medical and Biological Agency.

This enzyme is involved in the hydrolysis of acetylcholine, the accumulation of this neurotransmitter leads to the appearance<...>In this case, biomarkers of poisoning are compounds Adducts of proteins with POF Hydrolysis Extraction<...>neurotransmitter acetylcholine to choline and acetic acid, which is essential process necessary<...>acid obtained by enzymatic hydrolysis of AChE by GC-MS method.<...>acetylcholine, thus establishing the fact of FOV poisoning can be established by determining

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Modified electrodes for voltammetry in chemistry, biology and medicine

Moscow: Laboratory of Knowledge

The scientific publication outlines the theoretical foundations for the creation and mechanisms of functioning of voltammetric chemical sensors and biosensors based on modified electrodes in solving problems of chemistry, biology and medicine, monitoring environmental objects. Much attention is paid to new directions in the design and application of modified electrodes - the use of nanoparticles and ionic liquids, biomaterials, electrically conductive polymers, self-organizing, multisensor systems such as " electronic tongue”, detection of substances in the flow.

For example, cholinesterase catalyzes the hydrolysis of acetylcholine, a substance that does not contain a chiral center.<...>Similarly, the presence of acetylcholine, a neurotransmitter involved in the transmission<...>In living organisms, these enzymes catalyze the reaction of only one substrate - acetylcholine.<...>Since acetylcholine is one of the most important and versatile neurotransmitters providing<...>At the end of the XX century. was recorded annually up to Acetylcholine Choline Cholinesterase Copyright JSC Central Design Bureau BIBCOM &

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Organic chemistry. At 4 h. Ch. 3 tutorial

Moscow: Laboratory of Knowledge

The textbook systematically describes organic compounds by class, and also outlines the main theoretical provisions of organic chemistry. The structure and properties of organic compounds are considered from the positions of both the theory of electronic displacements and the theory of molecular orbitals. The third part includes chapters on the chemistry of carbonyl compounds (aldehydes, ketones), carboxylic acids and their derivatives, as well as nitrogen-containing organic compounds (amines, nitro and diazo compounds, azides), phenols, quinones, and cycloalkanes.

Acetylcholine performs a vital function in the process of transmitting a nerve impulse to muscle tissue.<...> <...>This is easily achieved by the enzyme cholinesterase, which catalyzes the hydrolysis of acetylcholine to<...>In order for it to return to its original state (relaxed), acetylcholine must be destroyed.<...>This is easily achieved by the enzyme cholinesterase, which catalyzes the hydrolysis of acetylcholine to

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No. 5 [Russian pharmacies, 2016]

As a reversible cholinesterase inhibitor, Ipigrix prevents the enzymatic hydrolysis of acetylcholine.

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No. 21 [Russian pharmacies, 2010]

Russian Pharmacy magazine is a federal-level industry publication aimed at pharmacy professionals. Among the authors of the journal are well-known scientists, pharmacy managers, top managers, leading analysts. Information support of the journal is carried out by the company RMBC (REMBC) - Research, Marketing, Bussiness Counsulting (Marketing research, business consulting).

Glutamatergic, dopaminergic, noradrenergic; an increase in the concentration of the neurotransmitter acetylcholine<...>Ipidacrine (Aksamon) reversibly inhibits acetyl buterylcholinesterase, prevents enzymatic hydrolysis<...>acetylcholine (ACH) and prolongs its action, thereby improving the transmission of excitation in the neuromuscular<...>The antiseptic and anti-inflammatory effect is due to hydroquinone, which is released in the body during hydrolysis.<...>The therapeutic effect is enhanced by the specific action of tannins and their hydrolysis products.

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Biological chemistry: teaching aid. Direction of training 060301.65 (33.05.01) - Pharmacy. Graduate qualification - specialist

NCFU publishing house

The manual contains control and testing questions and exercises that help to consolidate the material, increase students' interest in studying the discipline, make the learning process more accessible, easy and independent. Testing contributes to the study of the subject, excludes a formal approach to the assimilation of the material. Performance test items not only helps to realize self-control, but also allows you to independently improve and deepen knowledge, which also contributes to the development of interest in the subject. Designed for students studying in the direction of preparation 060301.65 (33.05.01) - Pharmacy

In the nerve endings, acetylcholine is produced (a mediator - a transmitter of nerve excitation).<...>Acetylcholine is the acetate ester of choline. Write the formula for acetylcholine. 28.<...>Calculate the percentage of choline in lecithin and acetylcholine. 3.<...>The enzyme acetylcholinesterase catalyzes the hydrolysis of acetylcholine: acetylcholine + H2O → choline +<...>The enzyme choline acetyltransferase transfers an acetyl group to a choline molecule: acetyl-CoA + choline → CoA + acetylcholine

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Enzymatic catalysis

VSU Publishing House

This tutorial provides the basic methods of working with enzymes, characterizes enzymes as biological catalysts, as well as their cofactors. The main attention is paid to the mechanisms of enzyme action, the kinetics of enzymatic reactions, the effect of inhibitors and activators on the rate of enzymatic reactions. In addition, material is presented on the biosynthesis of enzymes and their degradation, a characteristic is given to multienzyme complexes, ribozymes and catalytic antibodies (abzymes).

acetylcholine to choline and acetic acid: When inhibitors are added, acetylcholinesterase activity<...>Scheme of the active center of acetylcholinesterase: A - addition of acetylcholine in the active center of the enzyme<...>The arrow indicates the site of hydrolysis of the ester bond in the acetylcholine molecule; B - joining a competitive<...>The site of proserin hydrolysis is indicated, however the reaction is much slower than with acetylcholine; B - connection<...>Endrophonium binds to the active site of acetylcholinesterase, preventing the addition of acetylcholine

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Post-reflex neurobiology of behavior

How are the commands that the brain gives to the executive organs formed? For centuries it was believed that nervous activity reflex, that is, it obeys a simple and seemingly self-evident rule: a stimulus is a response. But careful researchers have long questioned this rule. The reflex paradigm was especially damaged by ethologists (field zoologists), who connected the behavior of animals with spontaneous (spontaneous, endogenous) processes in the brain. Since the 1960s the postulates of ethology are confidently confirmed by verification by methods of cellular neurophysiology; neuroethology was born. The book by V. E. Dyakonova and D. A. Sakharov expresses a neuroethological view of the organization and functioning of the nervous system. The experience of their own research allows the authors to pay special attention to the central pattern generators - neural ensembles responsible for the endogenous generation of ordered behavioral acts. Are ideas about central generators applicable to the mechanisms of mental acts? The authors inevitably involve the reader in a discussion of the prospects of the post-reflex paradigm.

acetylcholine.<...>in these synapses of gastropods, not due to hydrolysis of acetylcholine by cholinesterase, but for another reason<...>So, providing cholinergic synapses with an enzyme that hydrolyzes acetylcholine is a relatively<...>acetylcholine.<...>one extremely interesting detail: in two different lines of evolution of cephalopods - in octopods and decapods - for hydrolysis

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Collection of tests on toxicological chemistry

Moscow: Laboratory of Knowledge

This collection was written by the staff of the Department of Pharmaceutical and Toxicological Chemistry. A.P. Arzamastsev Institute of Pharmacy FGAOU HE First Moscow State medical university them. THEM. Sechenov, edited by Dr. Pharm. sciences, prof. G.V. Ramenskaya. Tasks contribute to the formation of skills and abilities necessary for the practical activities of a pharmacist in the field of toxicology. The tests check the level of students' training in general and biochemical toxicology, methods of sample preparation and chemical-toxicological analysis of groups of "metallic" poisons, "volatile" poisons, pesticides, carbon monoxide, acids and alkalis, medicinal and narcotic substances.

RIO PGSKHA

The manual provides the theoretical material necessary for the assimilation of discipline by students. Examples, illustrations and tabular material are provided to make the topics and individual issues easier to understand.

In the hydrolysis of fats, bile secreted by the liver plays a significant role.<...>Hydrolysis of polysaccharides.<...>So, during the hydrolysis of starch, the end products of decomposition are maltose and D-glucose, then hydrolysis<...>Amylopectin is also hydrolyzed to residual dextrin, the end product of hydrolysis, which is<...>acetylcholine to choline and acetic acid.

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Pharmacology textbook

Moscow: Laboratory of Knowledge

The textbook was prepared by teachers of the Department of Pharmacology of the Institute of Pharmacy and Translational Medicine of the First Moscow State Medical University. THEM. Sechenov, taking into account all the requirements of the Federal State educational standard higher education last generation. The book presents the main pharmacological groups of drugs, their classification, chemical structure, pharmacokinetics, pharmacodynamics, indications and contraindications for prescription, side effects.

Esterases Hydrolysis esters Novocaine Amidases Hydrolysis of amides Novocainamide, xicaine, chlorpropamide<...>In the synaptic cleft, acetylcholine is rapidly hydrolyzed by the enzyme acetylcholinesterase to form choline.<...>Acetylcholinesterase hydrolyzes acetylcholine to choline and acetic acid.<...>The hydrolysis process lasts 100 μs.<...>Metabolized by hydrolysis, excreted in the urine.

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Scientific foundations of biotechnology. Part I. Nanotechnologies in biology textbook. allowance

Moscow: Prometheus Publishing House

This edition introduces the reader to wonderful world nanotechnology - a multidisciplinary and interdisciplinary field scientific knowledge and technology, which is the main modern trend in the development of science and production. The purpose of the publication is to familiarize future teachers with the essential elements of nanotechnology and, taking into account the biological orientation of students, with the specifics of nanobio- and bionanotechnologies based on the use of living organisms (phages, viruses) and biomolecules, their components (proteins, lipids, nucleic acids, etc.). etc.), as objects of nanotechnological developments, as well as manifestations, discoveries and implementation of nanobiotechnological processes in various branches of science and production, medicine, pharmacology, monitoring, security, social sphere etc.

The monograph is devoted to the most important area of prevention in dentistry - the use of fluorine compounds to prevent dental caries. The paper highlights the place of fluorine in the environment, the exchange of fluorine, the physiological role of this trace element and the mechanism of its anti-caries action. Modern approaches to fluoride prophylaxis of dental caries are sufficiently fully covered. An example of drawing up a caries prevention program based on the use of fluorine compounds is given. Particular attention is paid to the toxic effect of fluorides. The results of studies conducted at the Department of Pediatric Dentistry of the KemGMA of Roszdrav are included, and the developments of the staff of this department are presented.

The monofluorophosphate ion releases free fluorine as a result of hydrolysis by phosphatases, usually<...>At the first stage, there is

In a textbook written by teachers of the Faculty of Chemistry of Moscow State University. M.V. Lomonosov, the modern theoretical foundations of chemical thermodynamics and chemical kinetics are outlined, and their practical applications are considered. Compared to the previous edition, the new edition has been significantly revised and supplemented. The book consists of two parts: in the first - theory, in the second - questions and tasks, examples control works, tables of physical and chemical data, basic physical and chemical formulas, as well as the necessary mathematical minimum and other useful applications. Answers or instructions for solving are given for all problems.

Calculate the heat of hydrolysis of sucrose.<...>The hydrolysis of acetylcholine is catalyzed by the enzyme acetylcholinesterase, whose turnover frequency is<...>How long does it take for an enzyme to break down one molecule acetylcholine hydrolyzes hydrolysis substrate CENTA β-lactamase TEM-1 (A) and TEM171 (B)<...>Acetylcholinesterase is responsible for the rapid hydrolysis of the neurotransmitter acetylcholine, leading to a break in transmission.<...>acetylcholine by the KM/MM method were first described in .<...>glucuronoxylan, and XylE is more efficient in the hydrolysis of arabinoxylan.<...>However, the silanes aqueous solutions are extremely active and hydrolyze very quickly Fig. 3.

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№5 [Cardiology in Belarus, 2013]

Covers topical issues of prevention, drug and surgical treatment of diseases of the heart and cardiovascular system. The publication assists in establishing links between specialists in the Republic of Belarus, as well as near and far abroad, provides a platform for the exchange of views on the use of new methods and technologies for the recognition, treatment and prevention of diseases of the cardiovascular system in childhood and adulthood.

influence of gonadectomy and hormone replacement therapy on the content and intensity of enzymatic hydrolysis<...>its hydrolysis in terms of total cholinesterase activity (OHEA).<...>The process of hydrolysis of ACh was also sensitive to hormonal imbalance.<...>The effect of gonadectomy on the mediator hydrolysis activity under experimental conditions showed a difference<...>activity of formation of ACh, taking into account the synergy of the process of synthesis of the mediator and its enzymatic hydrolysis

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Glossary of terms and definitions on the physiology and ethology of farm animals studies. allowance

Kalmyk State University

The glossary of terms and definitions on the physiology and ethology of farm animals is a systematic reference publication. Definitions in physiology form the basis for the scientific understanding of the most complex processes of vital activity occurring in the body of healthy animals.

Acetylcholinesterase An enzyme that blocks synapse function by hydrolyzing acetylcholine to acetate and choline<...>D, vasodilators: histamine, acetylcholine, rostostaglandins, brady1SHKININ circulate in the blood in small<...>end plate potential miniature potential arising from the spontaneous release of acetylcholine<...>Thiaminase is an enzyme that catalyzes the hydrolysis of thiamine.<...>Cholinesterase is an enzyme that breaks down acetylcholine, resulting in the restoration of synapse function.

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No. 8 [Clinical laboratory diagnostics, 2015]

Founded in 1955 Chief Editor– Titov Vladimir Nikolaevich, Doctor of Medical Sciences, Professor, Head of the Laboratory of Clinical Biochemistry of Lipid Metabolism, FBSI “Russian Cardiology Research and Production Complex” of the Ministry of Health of Russia. The journal has been published as a monthly professional scientific and practical publication since 1955 (until 1992 under the name "Laboratory Business"). For many years, the journal has been the main source of scientific and practical information for employees of clinical diagnostic laboratories and has played the role of an incentive to improve the laboratory provision of medical care. The journal publishes scientific and practical materials prepared by employees of scientific, educational and medical institutions in Russia and foreign countries: original articles, literature reviews, lectures by prominent specialists in various disciplines of laboratory medicine, descriptions of complex clinical and diagnostic cases of diseases, information on scientific and practical events, discussions between supporters of different approaches to solving urgent problems, the answers of scientists and healthcare organizers to the pressing questions of laboratory practitioners. Carries out the publication of translations of articles by foreign authors that are of the greatest scientific and practical interest for specialists in our country and published in professional scientific literature abroad (in particular, in the journal Clinical Chemistry, with which a corresponding agreement has been concluded).

Increase the parameters of TG hydrolysis by activating lipolysis on monolayer membranes of lipid "droplets"<...>Activate TG hydrolysis and oxidation of SFA + MFA in VFA, as occurs in brown adipose tissue cells,<...>Accumulation of palmitic triglycerides, which are hydrolyzed by HPFA and adipocyte lipase at a slow rate, results in<...>Hydrolysis of substrates (lipids, proteins, polysaccharides) in the stomach and small intestine. 2.<...>acetylcholine to choline and acid components (acetic, propionic or butyric acids).

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