EFFECTS OF ETHANOL ON THE ACTIVITY OF ADENOSINE TRIPHOSPHATASE AND ACETYLCHOLINESTERASE IN SYNAPTOSOMES ISOLATED FROM GUINEA-PIG BRAIN

Nerve ending fractions from guinea-pig cerebral cortex contained more than one-half of the Na-K ATPase activity present in the original homogenate. Ethanol at concentrations ranging from 0·043 to 2·57 m inhibited the Na-K ATPase to a significantly greater extent than the Mg-activated ATPase or AChE. The inhibition of membrane-bound Na-K ATPase by ethanol was of the non-competetive type and the activity of Na-K ATPase was increasingly inhibited by alcohols of increasingly longer chain length. The ability of various alcohols to inhibit membrane-bound Na-K ATPase activity was correlated with their lipid solubility.