Effect of vitamin A deficiency on the pulmonary and hepatic drug-metabolizing enzymes in rat.

The effect of vitamin A deficiency on the drug-metabolizing enzyme system of the lung and liver was analyzed in rats fed diets with or without vitamin A for 5-6 weeks. The hepatic level of vitamin A was significantly reduced in vitamin A deficient animals. The hepatic cytochrome P-450 and b5 contents and activity of benzo(a)pyrene hydroxylase was significantly reduced in deficient animals. Contrary to this, pulmonary cytochrome P-450 and b5 contents were above the control values. No alteration in pulmonary benzo(a)pyrene hydroxylase was noted. The uridine diphosphate-glucuronosyltransferase activity of digitonin-treated microsomal membranes was below the control values both in lung and liver. However, the native uridine diphosphate-glucuronosyltransferase activity remained unchanged in the liver and was below control values in the lung.