Effects of Calcium Dobesilate on Glomerulus TIMP1 and Collagen Ⅳ of Diabetic Rats

Summary ： To observe the effects of calcium dobesilate on the expression of glomerular tissue inhibitor of metalloproteinase 1 （TIMP1）, collagen Ⅳ , and ultrastrueture of glomerular basement mem- brane in diabetic rats, rats model of diabetes was established by unilateral nephreetomy and intraperitoneal injection of 1% STZ （55 mg/kg）, and rats were administered calcium dobesilate 100 mg/ kg （DD group） or distilled water （DM group） respectively. 12 weeks later, the changes in the renal uhrastrueture and ereatinine clearance rate （Cer） were examined in each group. The expression of glomerular TIMP1 and collagen Ⅳ were studied by immunohistoehemieal staining. Our results showed that after 12 weeks, the Cer in DD group increased and was significantly higher than that in DM group. Electron microscopy showed that thickness of glomerular capillary basement membrane （GBM） in Group DD was less than that of DM group. No hyperplasia of collagen fibers was found, and the distance betweeh the holes of endothelial cells in DD group was not as even as that in the normal group, but more even than that of DM group, and podocyte processes was still in order. Immunohistochemical staining of glomeruli showed that expression of TIMP1 and collagen Ⅳ in DD group were significantly less than those of DM group DM. It is concluded that calcium dobesilate can improve diabetic nephropathy by inhibiting the overaccumulation of collagen Ⅳ and calcium dobesilate may also contribute to diabetes by inhibiting the expression of TIMP1.