SR 95191, a selective inhibitor of type A monoamine oxidase with dopaminergic properties. II. Biochemical characterization of monoamine oxidase inhibition.

SR 95191 [3-(2-morpholino-ethyl-amino)-4-cyano-6-phenylpyridazine] is a novel psychotropic drug which possesses the pharmacological properties of a selective, reversible type A monoamine oxidase inhibitor (MAOI). The MAOI activity of SR 95191 was examined in the rat brain, liver and duodenum and compared to that of clorgyline, harmaline, l-deprenyl, moclobemide and cimoxatone. In vitro, SR 95191 selectively inhibited MAO-A and was less potent than cimoxatone, clorgyline and harmaline, but was more potent than moclobemide.

Effect of the antidepressant minaprine on both forms of monoamine oxidase in the rat.

The antidepressant minaprine (3-(2-morpholino-ethylamino) 4-methyl 6-phenyl pyridazine, dihydrochloride) and its main metabolites were examined for their monoamine oxidase (MAO) inhibitory effects in the rat. In our experimental conditions, minaprine displayed in vitro a very weak affinity for brain MAO A and B with IC50S close to 1 mM. However, ex vivo, after intraperitoneal administration, this drug behaved as a specific and short-acting type A MAO inhibitor (MAOI) of mild potency (ED50 = 12.