Hydrolysis of Choline Esters by Liver

Abstract
A sample of rat serum (largely pseudo-cholin-esterase) had an acetylcholine (ACh) hydrolyzing capacity in arbitrary units of 2.98. Guinea pig liver extract had 0.16 units. A mixture of rat serum and guinea pig liver extract had an activity of 3.13. The two activities are thus additive. The low ACh hydrolysis by guinea pig liver is not due to the presence of inhibitors. Guinea pig liver split benzoylcholine 5-11 times as rapidly as ACh. The enzyme concerned is called benzoylcholineesterase. In other guinea pig tissues and organs assayed, the hydrolysis of ACh is greater than that of benzoylcholine.