Cholinesterases in Human Spinal Fluid and Brain1

By electrophoresis and chromatography on DEAE‐cellulose it was shown that human spinal fluid and brain tissue extracts contained three cholinesterases: Two butyrylcholinesterases and one acetylcholinesterase. One of the butyrylcholinesterases had the same electrophoretic mobility as serum cholinesterases. The other butyrylcholinesterase moved together with the γ‐globulin and the acetylcholinesterase together with the %‐globulin fraction of spinal fluid. These findings indicate that the acetylcholinesterase in spinal fluid derives from brain whereas it can not be decided whether the butyrylcholinesterases originate from plasma or from brain. The low mobility fraction of butyrylcholinesterase may arise from the action of sialidase.