Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the hepatic storage of retinol in rats with different dietary supplies of vitamin A (retinol).

The effect of various dietary sources of vitamin A on liver storage of retinol has been investigated in Sprague-Dawley rats treated with single oral doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD): 0,0.1,1.0, or 10 microgram.kg-1. Each dose group consisted of 3 subgroups, each comprising 10 rats which received a diet with normal, low or high retinol content. The animals were killed 4 weeks after TCDD administration. Analyses of retinol were performed by high pressure liquid chromatography and glucuronosyltransferase activities were determined spectrophotometrically. A dose-dependent decrease in hepatic storage of retinol was evident. The high retinol diet did not fully compensate for the reduction caused by the highest TCDD-dose. Glucuronosyltransferase activity increased directly in relation to the TCDD-dose but in inverse proportion to the retinol content of the diet.