Response of Liver Enzymes and Other Proteins to Amino Acid Deficient Diets.

Abstract

Histidine-deficient diet can completely restore xanthine oxidase activity to livers of rats previously depleted of such activity by a non-protein diet; methionine-free and lysine-free diets partially restore such activity with the lysine-free diet the least active in this respect. Liver succinic oxidase activity can be similarly restored by histidine- and methionine-free rations but only partially restored by a lysine-free ration. Liver choline oxidase activity of protein-depleted rats can be restored partially and to about the same extent by the 3 amino acid-deficient diets studied. Liver nitrogen concentration follows approximately the same pattern as succinic oxidase in these studies. The enzymatic responses to a non-protein diet followed by single amino acid-deficient diets were compared to responses observed in earlier studies under conditions of initial single amino acid-deficient diets.