Cohen M P, Surma M L
J Lab Clin Med. 1981 Nov;98(5):715-22.
Isolated rat renal glomeruli incorporate radioactive sulfate into glycosaminoglycans, which are integral components of the glomerular basement membrane. Cellulose acetate electrophoresis and specific enzymatic sensitivities of glycosaminoglycans prepared after pronase digestion of purified glomerular basement membrane indicate the presence of heparan sulfate. We examined the effect of experimental diabetes on the incorporation of [(35)S]-sulfate into glycosaminoglycans deposited into newly synthesized glomerular basement membrane in vitro. Basement membranes were purified from glomeruli isolated from normal and streptozotocin-diabetic rats after incubation for 2 hr with radiolabeled sulfate and then were subjected to pronase digestion for isolation of the glycosaminoglycans. [(35)S] incorporation into basement membrane glycosaminoglycans was significantly decreased in glomeruli from diabetic animals. The addition of insulin (100 micron U/ml) in vitro did not affect [(35)S] incorporation into glycosaminoglycans of the glomerular basement membranes in normal or diabetic glomeruli. High glucose concentration (5 vs. 20 mM) was without effect in short-term incubations of glomeruli from normal animals. The results indicate that experimental diabetes influences [(35)S] sulfate incorporation into glomerular basement membrane glycosaminoglycans and suggest that decreased heparan sulfate production and/or sulfation may contribute to the increased permeability of the glomerular basement membrane in diabetes.
分离的大鼠肾小球可将放射性硫酸盐掺入糖胺聚糖中，而糖胺聚糖是肾小球基底膜的重要组成部分。对纯化的肾小球基底膜进行链霉蛋白酶消化后制备的糖胺聚糖进行醋酸纤维素电泳和特定酶敏感性分析，结果表明存在硫酸乙酰肝素。我们研究了实验性糖尿病对体外新合成的肾小球基底膜中沉积的糖胺聚糖掺入[³⁵S] - 硫酸盐的影响。在与放射性标记的硫酸盐孵育2小时后，从正常和链脲佐菌素诱导的糖尿病大鼠分离的肾小球中纯化基底膜，然后进行链霉蛋白酶消化以分离糖胺聚糖。糖尿病动物肾小球基底膜糖胺聚糖中[³⁵S]的掺入量显著降低。在体外添加胰岛素（100微单位/毫升）对正常或糖尿病肾小球基底膜糖胺聚糖中[³⁵S]的掺入没有影响。高葡萄糖浓度（5 mM对20 mM）对正常动物肾小球的短期孵育没有影响。结果表明，实验性糖尿病会影响[³⁵S]硫酸盐掺入肾小球基底膜糖胺聚糖，并提示硫酸乙酰肝素产生和/或硫酸化减少可能导致糖尿病时肾小球基底膜通透性增加。
