[Importance of the initial monoamine oxidase activity for the development of the activating or inhibiting action of indolylhydrazides].

Effects of beta-(2-methyl indolyl-3) propionic acid hydrazide and alpha-butyl-beta-(2-methyl-5-carboxy indolyl-3) propionic acid hydrazide on the activity of monoamine oxidase were studied in rat brain in vitro. The compounds activated distinctly serotonin deamination under conditions of the enzyme inhibition, caused by pretreatment with iproniazide. The activation occurred only in the samples, which were not inhibited with iproniazide. The treatment with iproniazide prevented any alterations in content of amines, caused by the compounds in the rat brain in vivo.