title: Role of monoamine oxidase A and B in the deamination of newly-formed dopamine in the rat kidney.
abstract: The present study has examined the effects of two selective inhibitors of monoamine oxidase (MAO) type A and B, respectively Ro 41-1049 and Ro 19-6327, on the deamination of newly-synthesized dopamine in kidney slices incubated with exogenous L-DOPA (50 and 100 mumol/l). Ro 41-1049 (50, 100 and 250 nmol/l) was found to produce a concentration-dependent increase of newly-formed dopamine (36-56% increase) and reduced DOPAC formation (45-86% reduction). Ro 19-6327 (50, 100 and 250 nmol/l), was found not to affect the accumulation of newly-formed dopamine at 50 mumol/l L-DOPA in the medium, but significantly reduced the formation of DOPAC. At the concentration of 100 mumol/l of L-DOPA, Ro 19-6327 (100 and 250 nmol/l) significantly increased (by 32% and 132%, respectively), the dopamine tissue levels in kidney slices and decreased DOPAC formation. It is concluded that both MAO-A and MAO-B are important in the metabolism of newly-formed dopamine in kidney slices incubated with exogenous L-DOPA.
authors.affiliation: Laboratório de Farmacologia, Faculdade de Medicina, Porto, Portugal.
authors.forename: M H
authors.initials: MH
authors.lastname: Fernandes
authors.forename: P
authors.initials: P
authors.lastname: Soares-da-Silva
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000494:pharmacology; D000818:Animals; D003641:Deamination; D004298:Dopamine / Q000378:metabolism*; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology*; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D010848:Picolinic Acids / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013844:Thiazoles / Q000494:pharmacology
chemical_list: D008996:Monoamine Oxidase Inhibitors; D010848:Picolinic Acids; D013844:Thiazoles; D015102:3,4-Dihydroxyphenylacetic Acid; C063456:Ro 41-1049; C059303:lazabemide; D007980:Levodopa; D008995:Monoamine Oxidase; D004298:Dopamine