Inhibition of noradrenaline deamination by antidepressants

Anti-norepinephrine deaminative activity of some antidepressants of different structure was studied. Pyrazidol (10(-5) M) reduced considerably the rate of norepinephrine deamination in bovine brain (80% inhibition), the inhibitory effects of inkazan and imipramine were also apparent (50-60%). Zimelidine, viloxazine and norzimelidine were found to be less active: at 10(-4) M, they caused a not more than 50% inhibition of oxidative norepinephrine deamination. The difference was revealed between the influence of some drugs on deamination of two monoamine oxidase A substrates: norepinephrine and serotonin. Thus, pyrazidol, viloxazine, zimelidine and norzimelidine were more active in suppressing norepinephrine, than serotonin deamination. Inhibition of norepinephrine deamination in the brain seems to be an important component of the neurochemical spectrum of pyrazidol and imipramine.