[Dietary protein as a modulator of the activity of enzymes metabolizing xenobiotics. UDP glucuronosyltransferase and glutathione transferase].

Activity of microsomal UDP-glucuronosyl transferase and cytosol glutathione transferase was studied in the liver and small intestine mucosa of rats which received rations with 5.18 and 33% of protein, during 2 months. Activity of UDP-glucuronosyl transferase GT1-isoform both in native and in detergent-activated microsomes of the liver increased with protein deficiency in the ration, while GT2-isoform activity and that of three glutathione transferase forms decreased. Excess of protein in the ration led to a growth of conjugation enzyme activity in the liver. The food protein level influenced the degree of GT1 and GT2 induction by benzyl but it did not change the capacity for induction of glutathione transferase. Activity of conjugation enzymes in the small intestine mucosa of rats to a lesser degree depended on the protein level in the ration.