A type of neurotransmitter (a chemical that transmits messages between nerve cells or between nerve and muscle cells). Acetylcholine is the neurotransmitter found at all nervemuscle junctions and at many other sites in the nervous system. The actions of acetylcholine are called cholinergic actions, and these can be blocked by anticholinergic drugs.
An acetic-acid ester of the organic base choline, acetylcholine is one of the substances which mediates the transmission of nerve impulses from one nerve to another, or from a nerve to the organ it acts on, such as muscles. It acts on both muscarinic receptors (blocked by ATROPINE and responsible for ganglionic and parasympathetic transmission and also for sympathetic innervation of sweat glands – see under AUTONOMIC NERVOUS SYSTEM) and nicotinic receptors (responsible for the transmission of nerve impulses to muscles and blocked by curare, thus causing paralysis). Acetylcholine is rapidly destroyed by cholinesterase, an ENZYME present in the blood. ANTICHOLINERGIC drugs such as PHYSOSTIGMINE prolong the action of acetylcholine.
n. the acetic acid ester of the organic base choline: the *neurotransmitter released at the synapses of parasympathetic nerves and at *neuromuscular junctions. After relaying a nerve impulse, acetylcholine is rapidly broken down by the enzyme *cholinesterase. *Antimuscarinic drugs block the action of acetylcholine at receptor sites; *anticholinesterases and *acetylcholinesterase inhibitors prolong the activity of acetylcholine by blocking cholinesterase.
A pharmaceutical preparation of acetylcholine is instilled into the anterior chamber of the eye as a *miotic during intraocular surgery.
any one of a class of drugs that block the action of acetylcholinesterase (see cholinesterase), an enzyme that quickly breaks down the neurotransmitter acetylcholine. This neurotransmitter is central to the functional interconnection between nerve cells in the outer layer (cortex) of the brain; the early impairment of cognitive function found in Alzheimer’s disease is associated with a reduction in acetylcholine levels. By inhibiting acetylcholine breakdown, acetylcholinesterase inhibitors have been found helpful in slowing down the rate of cognitive decline in mild to moderate dementia; they do not halt the progress of the disease. The group includes donepezil, galantamine, and rivastigmine... acetylcholinesterase inhibitor
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