In vivo effects of the monoamine oxidase inhibitors Ro 41-1049 and Ro 19-6327 on the production and fate of renal dopamine.

Ro 41-1049 (2 mg/kg), but not Ro 19-6327 (2 mg/kg), was found to reduce (70% to 93% decrease) DOPAC tissue levels in the renal cortex, outer and inner medulla and, to a similar extent, DOPAC concentrations in plasma. This inhibitory effect was, however, not accompanied by an increased accumulation of newly-formed dopamine. The results presented show that type A monoamine oxidase is the predominant form of the enzyme involved in the metabolism of renal dopamine and some of the amine which escapes deamination might leave the kidney through the renal vein in the intact from.