Specific Liver and Brain Monoamine Oxidase Inhibition by Alkyl- and Arylalkylhydrazines.

Abstract

Activity of several hydrazine derivatives selectively to inhibit liver or brain monoamine oxidase (MAO) in the intact rat has been compared. Of those studied, the compounds possessing an unsubstituted arylalkylhydrazine structure, such as benzyl hydrazine, [beta]-phenylethylhydrazine, and B-phenylisopropylhydra-zine showed greater brain than liver MAO inhibiting properties. Substitution on the terminal hydrazine with an isonicotinyl group reversed the brain-liver MAO inhibiting relationship. Compounds lacking the benzene ring as in methyl-, ethyl-, and isopropylhydrazine also showed greater liver than brain MAO inhibiting effects. It is concluded that the benzene ring of the unsubstituted aryl-alkylhydrazines may aid in their passage into the brain.