Studies on the Identification and Origin of Ethanol in Mammalian Tissues

Abstract

Abstract Ethanol has been identified as a normal trace constituent of mammalian tissue by criteria which include the reduction of nicotinamide adenine dinucleotide in the presence of yeast alcohol dehydrogenase and a tissue sublimate containing volatile substituents of the tissue; chromatographic identification of ethyl dinitrobenzoate after reaction of the sublimate with 3,5-dinitrobenzoyl chloride; and gas-liquid chromatography of benzoate derivatives prepared from tissue sublimates. Ethanol-14C is formed from sodium pyruvate-2-14C during incubation with liver slices under anaerobic conditions. Its formation is linear for the first hour and is dependent on the presence of low concentrations of pyruvate. The ability of pyruvate dehydrogenase isolated from pig heart to catalyze the formation of ethanol from pyruvate when coupled to an alcohol dehydrogenase-reduced nicotinamide adenine dinucleotide system has been investigated. Formation of ethanol requires, in addition to pyruvate dehydrogenase, pyruvate, NADH, thiamine pyrosphosphate, and Mg++. It is inhibited by semicarbazide and sodium bisulfite. The results support the view that the pyruvate dehydrogenase system produces free acetaldehyde which can be reduced to ethanol in the mammal.