Effects of three monoamine oxidase inhibitors on ethanol preference in mice.

These experiments investigated the effects of pargyline, N-[2-(o-Chlorophenoxy)-ethyl]-cyclopropylamine (Lilly 51641), and nialamide on voluntary ethanol consumption of C57BL/6J mice. Both pargyline and Lilly 51641 reduced ethanol preference; in contrast, nialamide did not affect preference, despite the fact that it inhibited MAO activity by more than 90%. A subsequent experiment determined that both pargyline and Lilly 51641 produced substantially greater elevations in acetaldehyde levels than did nialamide. It is suggested that increased acetaldehyde is the mechanism responsible for the reduction in ethanol preference observed with pargyline and Lilly 51641.