Simvastatin protects diabetic rats against kidney injury through the suppression of renal matrix metalloproteinase-9 expression

Objective : To observe the effects of simvastatin on urinary excretion of matrix metalloproteinase-9 (MMP-9), renal expression of MMP-9, and investigate its possible renoprotective mechanisms in streptozotocin (STZ)-induced diabetic rats. Method : Twenty-four Wistar rats were divided into 3 groups: control healthy rats (group C, no.=8), untreated diabetic rats (group D, no.=8), and diabetic rats treated with simvastatin (20 mg/kg/d) (group S, no.=8). Peripheral blood glucose was tested weekly, glycosylated hemoglobin A 1c (HbA 1c ), total cholesterol (TC), LDL cholesterol (LDL-C) levels, and urinary albumin (ALB) excretion rate as well as the urinary excretion rates of retinol-binding protein (RBP) and MMP-9 were tested at 8 th week. The renal tissues of diabetic rats were obtained for evaluating kidney/body weight ratio, observing renal pathological changes by electron microscope and examining the expression of renal MMP-9 mRNA by RT-PCR. Results : There was no statistical difference on the change of peripheral blood TC and LDL-C between group C and group D. Peripheral blood glucose, HbA 1c levels kidney/body weight ratio urinary excretion rates of ALB, RBP, and MMP-9 concurrently with the expression of renal MMP-9 mRNA were significantly higher in groups D and S compared with group C ( p