butyylikoliinesteraasin

Butyylikoliinesteraasin, also known as butyrylcholinesterase (BChE) or pseudocholinesterase, is an enzyme in the cholinesterase family that hydrolyzes choline esters such as butyrylcholine and acetylcholine. It is primarily produced by the liver and released into the bloodstream, where it participates in the metabolism of various ester-containing compounds.

The enzyme plays a role in detoxification of certain drugs and toxins, and serves as a scavenger for organophosphates, reducing the duration of effect of some nerve agents and pesticides. BChE is less substrate-specific than acetylcholinesterase and acts on a range of choline esters, including the depolarizing anesthetic succinylcholine, which is rapidly hydrolyzed by BChE to terminate its neuromuscular effect.

Activity is genetically determined and varies among individuals. The BCHE gene encodes the enzyme; several genetic variants can reduce activity. Measurements such as the dibucaine inhibition test estimate the proportion of normal enzyme activity; a low dibucaine number indicates an abnormal phenotype. Factors such as age, liver disease, pregnancy, malnutrition, and certain medications can also influence BChE activity.

Clinically, reduced BChE activity can cause prolonged apnea after administration of succinylcholine during anesthesia. Diagnosis relies on plasma cholinesterase activity testing. In toxicology, BChE activity can serve as a biomarker of exposure to organophosphates, though acetylcholinesterase inhibition is the primary clinical concern.