Effect of Repeated Oral Administration of Monoamine Oxidase Inhibitors On Rat Brain Amines

Abstract

Daily oral administrations of tranyl-cypromine (trans-2-phenyl-cyclopropylamine) (5 mg/kg, b. i.d.) or of iproniazid (1-isonico-tinyl-2-isopropyl hydrazine) (50 and 100 mg/kg, b. i. d.) to male albino rats, Wistar strain, for periods of from 3 to 10 days resulted in cumulative increases in brain serotonin concentration of from 2 to 4 times that produced by a single administration of the drug. The increase in norepinephrine concentration was not appreciably different from that following a single administration of the drug. No significant or consistent effect upon the spontaneous motor activity of the rats was observed.