[Modification of mitochondrial monoamine oxidase activity by certain amine inhibitors].

Monoamine oxidase inhibitors /trans-2-phenylcyclopropylamine, pyrazidol, phenharmane/ belonging to the category of primary or secondary amines, in the molecule of which/ after dehydration/ formation of an azomethine bond is possible, modified the activity of membrane bound bovine brain monoamine oxidases inhibiting the deamination of serotonin and, at the same time, causing appearance of or significant increase in cadaverine--or histamine--deaminating properties. This modification was not caused either by primary amines /amphetamine, GABA/ which are not potent monoamine oxidase inhibitors or by the amines possessing strong monoamine oxidase inhibiting properties/pargylline, deprenyl, harmine/ but devoid of the potential property of forming an azomethine bond. In vivo trans-2-phenylcyclopropylamine, pyrazidol or phenharmane /contrary to amphetamine/ did modify the monoamine oxidase activity in brain of mice inducing the deamination of histamine and decreasing its tissue concentration.