The Plasma Cholinesterases: A New Perspective

Abstract

Publisher Summary This chapter presents a discussion of plasma cholinesterases. The whole field of cholinesterase polymorphism, and much of pharmacogenetics, is opened up by the clinical observation that in certain patients receiving succinylcholine, prolonged apnea developed. The best known clinical application of cholinesterase assay concerns the abnormally prolonged effect of the muscle relaxant succinylcholine that is found in a small proportion of patients. The cholinesterases are accepted as being synthesized in the liver and the assay of cholinesterase first became of interest to the clinician and to the clinical chemist as a test of liver function. Low serum cholinesterase activities are found in acute hepatitis, acute cirrhosis, and in liver metastases in those conditions where the hepatic synthesis of the protein is impaired. The synthesis of several other proteins is also reduced in such conditions, so that cholinesterase assay has been largely superseded as a test of liver function by measurements related to proteins such as albumin and prothrombin. Recommended procedures for collecting and storing plasma and serum specimens and laboratory procedures used for distinguishing the more common serum cholinesterase variants are also discussed in the chapter.