A STUDY OF MEASUREMENT OF CHOLINESTERASE BY CONSTANT-PH TITRATION - EFFECT OF HEMOLYSINS AND A COMPARISON WITH ELECTROMETRIC TECHNIQUE

Estimates of the degree of inhibition of cholinesterase activity in samples of blood from human beings by 1-naphthyl N-methylcarbamate (carbaryl, Sevin) and by diethylparanitrophenylphosphate (paraoxon) are higher by constant-pH titration than by the electrometric method of Michel. The hemolysin, alkyl phenoxy polyethoxy ethanol (Triton X-100), 0.2%, inhibits approximately 70% of the acetylcholine-hydrolyzing ability of blood plasma and therefore results in low estimates of acetylcholinesterase when used with whole blood and with plasma, if acetylcholine is used as the substrate. © 1969.