INHIBITION OF AMINE OXIDASE BY METAL IONS AND BY SULPHYDRYL COMPOUNDS

Abstract

Metal compounds were studied for possible effects on the amine oxidase system of rat liver. Some activated, others inhibited this system. Certain compounds exhibited both actions, the former being detectable at the lower concentrations. The data obtained extend the evidence of others for amine oxidase as a sulphydryl enzyme, but other mechanisms for metal inhibition of amine oxidase must also be considered. The actions of sulphydryl compounds on amine oxidase activity were investigated. BAL, thioglycollic acid, cysteine, and cystine were inhibitors, glutathione activated the enzyme system under certain conditions. Intravenous administration to rats of mercuric acetate, cadmium chloride, lead acetate, and manganese sulphate, all being in vitro inhibitors of amine oxidase, did not affect the enzyme activity of brain and liver in acute experiments.