Interactions between substituted tryptamine analogues, MAO inhibitors and cytochrome P-450.

The effects of some MAO inhibitors, N-acetylenic analogues of tryptamine, on rat liver microsomal cytochrome P-450 (cyt P-450) have been investigated. All the compounds tested interacted with cyt P-450 with Ks values ranging between 14 and 358 microM (clorgyline Ks = 10.5 microM). Compounds with a tertiary amine and those possessing a secondary amine group in the acetylenic side chain exhibited type I and type II difference spectra, respectively. Aniline hydroxylase activity was inhibited irreversibly and in a time-dependent fashion by all compounds tested with IC50 ranging between 7 x 10(-5) and 7 x 10(-3) M (clorgyline 10(-4) M)