Description
Acetylcholine is a neurotransmitter that binds to nicotinic and muscarinic acetylcholine receptors (AChRs) in the central and peripheral nervous systems. It mediates motor function at the neuromuscular junction but also has functions in the parasympathetic and sympathetic nervous systems. It is involved in learning and memory through actions at nicotinic AChRs in the CNS. The actions of acetylcholine are terminated primarily
via the action of acetylcholinesterase, which breaks it down into acetate and choline. Acetylcholine (chloride) mimics the effects of acetylcholine and has been used to determine the function of acetylcholine in various biological processes. Acetylcholine (chloride) inhibits peptide aggregation of p53 mutants
in vitro at micromolar concentrations. It increases alveolar fluid clearance in a dose-dependent manner and enhances Na
+/K
+-ATPase activity, effects which are blocked by atropine , in a mouse model of pulmonary edema.
Chemical Properties
A white or almost white crystalline powder, or colorless crystals, highly hygroscopic, with a faint ammoniacal odor and a very salty taste. Melting point: 149-152°C. The pH of a 10% aqueous solution is approximately 5, and the substance rapidly decomposes in hot water and alkaline solutions. It is highly soluble in water, ethanol, and propylene glycol; soluble in chloroform and acetic acid; and insoluble in ether. The product exhibits low toxicity, with an LD50 (oral, rat) of 2500 mg/kg.
Uses
Acetylcholine Chloride is a cholinergic, antiarrhythmic, miotic, vasodilator (peripheral).
Definition
ChEBI: Acetylcholine chloride is the chloride salt of acetylcholine, and a parasympatomimetic drug. It contains an acetylcholine.
Application
Acetylcholine Chloride is a cholinergic neurotransmitter that can induce the opening of calcium channels and endogenous neurotransmitter at cholinergic synapses; amplifies sarcolemma action potential inducing muscle contractions.
Preparation
Acetylcholine chloride is synthesized by reacting chloroethanol and trimethylamine aqueous solution, followed by acylation with acetic anhydride.
brand name
Miochol (Novartis).
General Description
Acetylcholine chloride exerts a powerfulstimulant effect on the parasympathetic nervous system.Attempts have been made to use it as a cholinergic agent,but its duration of action is too short for sustained effects,because of rapid hydrolysis by esterases and lack of specificitywhen administered for systemic effects. It is a cardiacdepressant and an effective vasodilator. Stimulation of thevagus and the parasympathetic nervous system produces atonic action on smooth muscle and induces a flow from thesalivary and lacrimal glands. Its cardiac-depressant effectresults from (a) a negative chronotropic effect that causes adecrease in heart rate and (b) a negative inotropic action onheart muscle that produces a decrease in the force of myocardialcontractions.
Biological Activity
Endogenous neurotransmitter. Acts at nicotinic and muscarinic acetylcholine receptors.
Biochem/physiol Actions
Acetylcholine chloride, injected at 20 mg/kg body weight, reduces mortality and plasma proinflammatory cytokines in mice with experimentally-induced sepsis . The cholinergic anti-inflammatory mechanism is probably mediated by interaction of acetylcholine with α7n cholinoreceptor on monocytes, macrophages, and neutrophils, which decreases the levels of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6.
Clinical Use
Atropine blocks the depressant effect of ACh on cardiacmuscle and its production of peripheral vasodilation (i.e.,muscarinic effects) but does not affect the skeletal musclecontraction (i.e., nicotinic effect) produced.ACh chloride is a hygroscopic powder that is available inan admixture with mannitol to be dissolved in sterile waterfor injection shortly before use. It is a short-acting mioticwhen introduced into the anterior chamber of the eye and isespecially useful after cataract surgery during the placementof sutures. When applied topically to the eye, it has littletherapeutic value because of poor corneal penetration andrapid hydrolysis by AChE.
Safety Profile
Poison by subcutaneous, intravenous, and parenteral routes. Moderately toxic by ingestion. When heated to decomposition it emits very toxic fumes of NOx, and Cl-. A cholinergic agent. See also CHOLINE ACETATE (ESTER).
Purification Methods
It is very soluble in H2O (>10%), and is very hygroscopic. If pasty, dry it in a vacuum desiccator over H2SO4 until a solid residue is obtained. Dissolve this in absolute EtOH, filter it and add dry Et2O, when the hydrochloride separates. Collect by filtration and store it under very dry conditions. [Jones & Major J Am Chem Soc 52 307 1930.] The chloroplatinate crystallises from hot H2O in yellow needles and can be recrystallised from 50% EtOH, m 242-244o [Dudley Biochem J 23 1069 1929]; other m given is 256-257o. The perchlorate crystallises from EtOH as prisms m 116-117o. [J Am Pharm Assocn 36 272 1947, Beilstein 4 IV 1446.]
