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

Repeated daily oral administrations of tranylcypromine or iproniazid 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.

Abstract

Repeated daily oral administrations of tranylcypromine (trans-2-phenyl-cyclopropylamine) (5 mg/kg, b.i.d.) or of iproniazid (1-isonicotinyl-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.