Protective effects of captopril in diabetic rats exposed to ischemia/reperfusion renal injury

Objectives To investigate the potential protective effects of captopril, the angiotensin-converting enzyme inhibitor, in diabetic rats exposed to ischaemia/reperfusion (I/R) renal injury. Methods Following successful induction of diabetes, captopril treatment (50 mg/kg/day, p.o.) was applied for 4 weeks, after which bilateral renal ischaemia was induced for 30 min followed by reperfusion for 24 h. Results Captopril significantly attenuated hyperglycaemia and hypoinsulinaemia in diabetic rats, and significantly reduced the elevations of serum creatinine and aldosterone levels, and renal malondialdehyde, tumour necrosis factor-alpha and nitric oxide (NO), and prevented the depletion of reduced glutathione caused by I/R in diabetic rats. Histopathological renal tissue damage induced by I/R in diabetic rats was ameliorated by captopril treatment. Immunohistochemical analysis revealed that captopril significantly attenuated the reduction of insulin content in pancreatic islet beta-cells, and decreased the I/R-induced expression of inducible NO synthase, nuclear factor-kappa B, Fas ligand and caspase-3, and increased the expression of survivin and heme oxygenase-1 in the kidney tissue of diabetic rats. Conclusions Captopril represents a potential candidate to reduce the risk of renal injury induced by ischaemia/reperfusion in type 2 diabetes.