Definition

Noun: * An enzyme that breaks down acetylcholine: Cholinesterase is a specific type of enzyme that catalyzes the hydrolysis (breakdown) of the neurotransmitter acetylcholine into its components, choline and acetic acid. This action is crucial for terminating the signal at cholinergic synapses in the nervous system and neuromuscular junctions.

Usage

• Cholinesterase is essential for proper muscle function and nerve signaling.
• The activity of cholinesterase can be inhibited by certain drugs, nerve agents, and pesticides.
• Doctors may measure serum cholinesterase levels to monitor exposure to organophosphate compounds.

Examples

• The rapid action of cholinesterase ensures that muscle contractions are brief and precise.
• Some insecticides work by inhibiting the enzyme cholinesterase in insects.
• A test for pseudocholinesterase, a related form of the enzyme, is sometimes given before surgery.

Advanced Usage

• Acetylcholinesterase (AChE): Often used synonymously with "cholinesterase" in a strict biological context, AChE is the primary form found at neuromuscular junctions and in the brain.
• Butyrylcholinesterase (BuChE or pseudocholinesterase): A related plasma enzyme that also hydrolyzes acetylcholine but has a broader substrate specificity and is produced in the liver.

Variants and Related Words

• Acetylcholinesterase (n): The specific type of cholinesterase that rapidly hydrolyzes acetylcholine at synaptic sites.
• Anticholinesterase (n): A substance (e.g., a drug or toxin) that inhibits the action of cholinesterase.
• Cholinergic (adj): Relating to or denoting nerve cells that use acetylcholine as their neurotransmitter.

Synonyms

• Acetylcholinesterase (in specific contexts)
• Choline esterase

Related Terms and Concepts

• Neurotransmitter: A chemical substance released by a nerve cell to transmit an impulse.
• Enzyme inhibitor: A molecule that binds to an enzyme and decreases its activity.
• Synapse: The junction between two nerve cells, where signal transmission occurs.

Noun

1. an enzyme that hydrolyses acetylcholine (into choline and acetic acid)