Description
Serum cholinesterase (pseudocholinesterase, cholinesterase II or PCHE) is found in the liver,
pancreas, heart, serum and in the white matter of the brain. This serum enzyme should not be
confused with cetylcholinesterase from erythrocytes (EC 3.1.1.7), which is also referred to as
cholinesterase I. The biological function of cholinesterase is unknown. Clinically, it serves as an
indicator of possible insecticide poisoning, and is measured as an index of liver function. Pre
operative screening of cholinesterase is used to detect patients with atypical forms of enzyme and
hence avoid prolonged apnea caused by slow elimination of muscle relaxants. Depressed
cholinesterase levels are found in cases of intoxication with organophosphorus compounds and in
hepatitis, cirrhosis, myocardial infarction, acute infections and atypical phenotypes of the enzyme.
