INTERACTIONS BETWEEN SUBSTITUTED TRYPTAMINE ANALOGS, MAO INHIBITORS AND CYTOCHROME-P-450

The effects of some MAO inhibitors, N-acetylenic analogues of tryptami ne, on rat liver microsomal cytochrome P-450 (cyt P-450) have been inv estigated. All the compounds tested interacted with cyt P-450 with Ks values ranging between 14 and 358 mu M (clorgyline Ks = 10.5 mu M). Co mpounds with a tertiary amine and those possessing a secondary amine g roup in the acetylenic side chain exhibited type I and type II differe nce spectra, respectively. Aniline hydroxylase activity was inhibited irreversibly and in a time-dependent fashion by all compounds tested w ith IC50 ranging between 7 x 10(-5) and 7 x 10(-3) M (clorgyline 10(-4 ) M).