Insulin and metabolism of glycosaminoglycans in rabbits

The effect of insulin on the concentration of different glycosaminoglycan (CG) fractions was different in different segments of aorta. Chondroitin sulphate A and heparin were increased in the aortic arch, thoracic and abdominal aorta, while chondroitin sulphate B and C were increased only in the aortic arch and abdominal aorta. Heparin sulphate and hyalutonic acid were increased only in the abdominal aorta. In the liver, significant increases occurred in all GG fractions. All enzymes studied which are involved in the biosynthesis of GG precursors, i.e. glucosaminphosphate isomerase, UDP glucose dehydrogenase and glucose-1-phosphate uridylyltransferase, were increased in the animals of the insulin group, while all enzymes involved in the degradation of GG, i.e. hyalurono glucosidase, beta-glucosaminidase, arylsulphatase, and cathepsin D, were decreased. Concentration of hepatic PAPS, activity of the sulphate-activiting system and sulphotransferase increased on administration of insulin.