The Metabolism of Mucopolysaccharides in Animals

The turnover of the acid mucopolysaccharides, hyaluronic acid (HA) and chondroitinsulfuric acid (CSA), of skin has been studied in normal rats (1) and in animals treated with the adrenocortical hormones, 17-hydroxycorticosterone and 11-dehydro-17-hydroxycorticosterone (2). It was shown that the administration of these adrenal steroids to otherwise normal rats resulted in a decreased turnover of the mucopolysaccharides of skin. The possibility that insulin participates in the metabolism of acid mucopolysaccharides was suggested by the finding that both the uranic acid and hexosamine moieties of HA derive from glucose (3-5). Since insulin regulates the utilization of glucose, it seemed reasonable to postulate a role for insulin in the biosynthesis of the mucopolysaccharides. It is the purpose of this paper to present evidence that mucopolysaccharide metabolism is impaired in the skin of alloxan-diabetic rats and is restored toward normal by insulin administration. A portion of this investigation was published previously in preliminary form (6).