EFFECTS OF ANTIHYPERTENSIVE DRUGS OR GLYCEMIC CONTROL ON ANTIOXIDANT ENZYME-ACTIVITIES IN SPONTANEOUSLY HYPERTENSIVE RATS WITH DIABETES

The activities of glomerular intrinsic antioxidant enzymes (AOEs) were measured in a diabetic spontaneously hypertensive rat (SHR) model. Th e effects of antihypertensive drugs, i.e. captopril or triple therapy (hydralazine, reserpine, and hydrochlorothiazide), on glomerular intri nsic AOE activities in this model were evaluated. The effects of blood glucose control on the AOE activities were also determined. The aim o f the present study was to determine whether activities of glomerular intrinsic AOEs might correlate with disease activity in diabetic SHR. This study showed a decrease of glomerular intrinsic AGE, i.e. Cu/Zn-S OD and Mn-SOD (SOD = superoxide dismutase), glutathione peroxidase, an d catalase, activities in diabetic SHR. Glomerular Cu/Zn-SOD or Mn-SOD , glutathione peroxidase, and catalase activities in nondiabetic SHR w ere slightly lower than those in nondiabetic WKY rats. These activitie s in diabetic SHR were significantly improved after captopril or tripl e therapy or blood glucose control. The levels of urinary albumin excr etion, creatinine clearance, and glomerular tuft areas in diabetic SHR were also improved after the therapy. It appears that hypertension an d hyperglycemia may influence the glomerular intrinsic AOE activities, albuminuria, creatinine clearance, and glomerular tuft areas in diabe tic SHR. Thus, it is indicated that control of blood pressure or blood glucose is a very important factor for preventing renal injuries in t he diabetic SHR model.