Isolation of Rat Liver Heparan Sulfate and the Effect of Streptozotocin-Induced Diabetes on Its Chemical Structure

Abstract

The effect of streptozotocin-induced diabetes on the structure of heparan sulfate (HS) prepared from rat liver glycosaminoglycans (GAG) was evaluated. GAG were isolated and purified from the livers of diabetic and age-matched control rats by standard procedures. The HS sample was prepared from GAG by digestion with chon-droitinase ABC and precipitation with cetylpyridinium chloride. The HS sample, including an unknown substance, was further purified by Sephadex G-100 chromatography. The HS fraction was confirmed to consist only of HS by electrophoresis on a cellulose acetate strip.
The amount of HS was decreased in the diabetic group. The Sephacryl S-300 HR column chromatogram of the HS from the control group indicated that the normal liver HS consisted of at least two kinds of HS, which probably originated from the cell surface HS proteoglycan (PG) and basement membrane HSPG. The former HS peak showed a decrease in height and heterogeneity with diabetes. The ratio of iduronic acid to glucuronic acid, which were clearly separated by HPLC, was higher in the diabetic liver HS than in the controls. The above information indicates that diabetes may influence the carbohydrate chain structure of HS in liver.
Quantitative and qualitative changes in the liver HS may contribute to the functional changes of HSPG in diabetic tissue.