EFFECT OF CHLORPROMAZINE ON THE CONCENTRATION OF ACETYLCHOLINESTERASE IN THE CEREBROSPINAL-FLUID OF RABBITS

Following administration of chlorpromazine (4 mg/kg i.v.), there was an increase of up to 5-fold in the concentration of acetylcholinesterase in rabbit cerebrospinal fluid sampled from the cisterna magna but not in cerebrospinal fluid from a lateral ventricle. The pattern of multiple molecular forms and specific activity of acetylcholinesterase in cerebrospinal fluid did not resemble that of blood plasma and so a breakdown of the blood-cerebrospinal fluid barrier can be excluded. The concentration of lactate dehydrogenase in cisternal cerebrospinal fluid did not change, hence a non-specific increase in permeability of cell membranes seems unlikely. Prior administration of atropine sulphate (3 mg/kg i.v.), but not the same dose of atropine methylnitrate, prevented the effect of chlorpromazine. The possibility that the rise in the concentration of acetylcholinesterase was the result of increased activity of central neurons containing this enzyme is discussed. © 1979.