[Influence of vitamin A on the distribution of glycosaminoglycans in rat tissues].

Glycosaminoglycans (GAG) from brains, intestines, livers and skin of rats were analyzed by electrophoretic and enzymatic methods. Variations in GAG distribution have been studied in rats fed on a vitamin-A-deficient diet and on a diet supplemented with an excessive quantity of vitamin A. Hypervitaminosis A resulted in a decrease in GAG isolated from connective and hepatic tissues. The incorporation of labeled sulfate into the GAG of these tissues has been studied. Hypervitaminosis A resulted in a decrease in sulfate incorporation into the GAG isolated from connective tissues. A large increase in sulfate incorporation into the GAC of the digestive tract is observed for vitamin-A-treated rats. A decrease is noted for vitamin-A-deficient rats. It was suggested that these variations in distribution and specific activity of GAG could be due to different effects of vitamin A. Vitamin A seems to be required either for the release of lysosomal enzymes or for the sulfatation and elongation of certain glucidic chains in the biosynthesis of sulfated GAG.