Pseudo-Cholinesterase of Brain

Abstract

SHORTLY after the distinction had been made between the true cholinesterase and the pseudo-cholinesterase^1,2, it was claimed that the brains of vertebrates contain true cholinesterase only³. This latter statement has proved to be incorrect; when large amounts of tissue are used for cholinesterase determinations, the presence of a small amount of pseudo-cholinesterase in brain can be demonstrated^4,5. Experiments with selective inhibitors of pseudo-cholinesterase have rendered it highly improbable that this enzyme would have any important role in the hydrolysis of acetylcholine released at nerve endings^6–8. However, the pseudo-cholinesterase in brain appears to be associated particularly with the myelinated fibre tracts of the central nervous system, and it has been suggested that the activity of this esterase may be connected with processes occurring in the myelin sheaths or neuroglial elements of the nervous system⁵.