Cholinergic, anticholinergic agents and hepatic ethanol metabolizing enzymes

The in vitro effects of some cholinergics and an anticholinergic agent on hepatic liver alcohol and aldehyde-dehydrogenase were investigated. Physostigmine was the only cholinomimetic agent which significantly inhibited hepatic mitochondrial aldehyde-dehydrogenase without concomitant changes in specific activity of alcohol dehydrogenase. This inhibitory action of physostigmine is found to be competitive and is confined to the enzyme with the low Km value which is also known to be inhibited by disulfiram. Kinetic studies were made to determine changes in the apparent Km value of aldehyde dehydrogenase by physostigmine. Additional experiments were performed to evaluate the Ki50 of physostigmine. The results are discussed in relevance to possible physostigmine-ethanol interaction and the complication of physostigmine in post-operative recovery procedures in individuals with alcohol intoxication and/or in alcoholic patients.