THE EFFECT OF TCDD ON ACYL COA-RETINOL ACYLTRANSFERASE ACTIVITY AND VITAMIN-A ACCUMULATION IN THE KIDNEY OF MALE SPRAGUE-DAWLEY RATS

Previous studies have shown that rats treated with 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) show signs of toxicity that are similar to the responses of animals to a vitamin A‐deficient diet. These include hypophagia, loss of body weight, loss of hepatic vitamin A, and accumulation of renal retinoids. Male Sprague‐Dawley rats treated with 10, 30, or 100 nmol/kg of TCDD accumulated renal vitamin A, with retinyl palmitate concentrations reaching 8 times those of control animals, similar to that of male rats fed a vitamin A‐free diet for 26 days. Acyl CoA:retinol acyltransferase (ACARAT) activities in both TCDD‐treated rats and rats fed a vitamin A‐free diet for 26 days were similarly elevated, and were strongly and positively correlated with the renal retinyl palmitate concentrations. Retinol concentrations in the kidneys of rats treated with TCDD or fed a vitamin A‐free diet were only slightly elevated when compared to control rats. We suggest that accumulation of retinyl esters in the kidneys of rats treated with TCDD or fed a vitamin A‐free diet occurs as a result of increased rates of retinol esterification. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company