Acetylcholine

Acetylcholine is a complex ether choline and acetic acidis a chemical transmitter nervous excitement (see Mediators). Formed in the body acetylcholine binds to proteins and inactive. Acetylcholine is released from binding with proteins in the transmission of nerve impulses. Nerve fibers in the endings of which is allocated acetylcholine, are called cholinergic. Acetylcholine is unstable. Released acetylcholine very quickly destroyed under the influence of the enzyme cholinesterase.
As the drug can use acetylcholine chloride (Acetylcholinum chloratum, Acetylcholini chloridum)related to cholinomimetic funds (see). Acetylcholine chloride is slowing heartbeat rate, expansion vessels, low blood pressure, reduced pupil, increased reduction of smooth muscles bronchiand intestines, bladder, increased secretion of sweat, digestive glands. Acetylcholine chloride effective only when parenteral introduction, its effect is short-lived. Acetylcholine chloride as a drug is usually not used. It is used mainly for the experiments.

Acetylcholine an ester of nitrogenous bases of choline and acetic acid. Plays the main role in conducting nerve impulses as chemical mediator in the synapses, the parasympathetic nervous system, as well as in somatic motor and preganglionarnah sympathetic fibers. The synapses, where the excitation is transmitted by means of acetylcholine, called cholinergic. A. is synthesized in the nervous system of free choline (see), entering the body with meal, or generated from endogenous ethanolamine and methionine, and acetylcodeine A. if the specific enzyme - cholinacetilasa in the presence of calcium ions. Generated A. almost entirely associated with proteins and in the form of inactive. This process is of great physiological significance, as it protects the body from accumulating more or less Significant quantities of free acetylcholine and blood.
The release of A. from its relationship with the squirrels in the transmission of nerve impulses is influenced by increasing the concentration of potassium ions, causing dissociation connection A. protein. Freed A. after performing the functions of a mediator of nervous excitement immediately decays with a gap of essential communication on choline and acetate. This process occurs with the specific and very powerful enzyme - true cholinesterase, in a large number contained in the nervous system. A number A., who had to go into the blood, destroyed specific erythrocyte cholinesterase and psevdoholinesterzoy serum. Rapid destruction A. fallen into the blood, is also of great importance, as was introduced intravenously A. dramatically slows the rate of heart contractions, extends arteriola reduces the clearance bronchi.
Cm. also the Mediators.