The turnover of the A- AND B-forms of monoamine oxidase in rat liver

Abstract

The inhibition of rat liver monoamine oxidase was determined following the intraperitoneal injection of the inhibitors clorgyline and pargyline in order to establish the concentration ranges in which substrate-selective inhibition occurred. The rate of recovery of the activity of the A-form of the enzyme after inhibition by clorgyline was determined using tyramine and serotonin as substrates, and the rate of recovery of the activity of the B-form after inhibition by pargyline was determined using tyramine and 2-phenylethylamine as substrates. No significant differences could be detected between the rates of recoveries of the two forms which corresponded to a rate constant for degradation of the enzyme of about 0.27 day -1.