Loss of sulfated carbohydrate from the glomerular podocyte as a cause of albuminuria in experimental diabetic rats: Ultrastructural histochemical study

Decrease of anionic sites and heparan sulfate proteoglycan has been demonstrated in diabetic glomerular basement membrane (GBM) and causally related to albuminuria. The HID-TCH-SP-PD technique is a sensitive histochemical method for negatively charged sulfated carbohydrates. In this study, we examined the localization of HID-TCH-SP-PD reaction in the glomeruli of diabetic and control rats. In both rats, the reaction was found in assciation with the surface of podocytes and with GBM. In diabetic rats, the former-associated reaction was markedly reduced. By contrast, the latter-associated reaction did not show any differences between both animal groups. Urinary albumin excretion (UAE) increased significantly in alloxanized rats. It is suggested that a decrease of podocyte-associated sulfated carbohydrates, the primary observed change, gives rise to albuminuria in alloxan diabetic rats.