Changes in the liver concentrations of the nicotinamide adenine dinucleotide coenzymes and in the activities of oxidoreductase enzymes following treatment of the rat with ethyl chlorophenoxyisobutyrate (Atromid-S)

Abstract

The effect of short periods of treatment (up to 2 months) with ethyl chlorophenoxyisobutyrate (CPIB) on the concentrations of nicotinamide adenine dinucleotide (pyridine nucleotide) coenzymes and on the activities of several oxidoreductase enzymes in rat liver has been described. The results were obtained in the equilibrium phase of the response to CPIB and a reproducible pattern of changes was found. The concentrations of both oxidized and reduced pyridine nucleotide coenzymes, particularly NAD, were raised, as were the activities of several dependent dehydrogenases. The activities of the reduced pyridine nucleotide:cytochrome-c dehydrogenases were either unaffected or reduced, as was the activity of tryptophan pyrrolase. The relationship of these results to the mode of action of CPIB is discussed.