Objective
The aim of this study was to evaluate the histopathological and biochemical effects of enalapril (an angiotensin-converting enzyme inhibitor) and pyridoxamine (an advanced glycation end product inhibitor) on the kidneys of streptozotocin diabetic female rats. Materials and methods
Eighty adult female rats weighing 150–200 g were used for the study and divided into four groups: group I (control nondiabetic group), group II (diabetic untreated group), group III (diabetic group treated with enalapril), and group IV (diabetic group treated with pyridoxamine), with each group comprising 20 rats (n = 20). Diabetes was induced by a single intraperitoneal injection of streptozotocin (55 mg/kg). Enalapril was administered (50 mg/l) in the drinking water and pyridoxamine was administered (1 g/l) in the drinking water for 28 weeks. Biochemical estimation of fasting blood glucose, serum creatinine, and plasma tumor necrosis factor-a (TNF-a) was performed. The kidneys of the rats were collected for examination of clinical biochemistry, which included measurement of levels of tissue malondialdehyde (MDA), enzymatic antioxidants such as superoxide dismutase (SOD) and catalase (CAT), and nonenzymatic antioxidants such as reduced glutathione (GSH), and were studied histopathologically by light microscopy and immunohistochemistry.
Results
Fasting blood glucose was significantly increased, whereas the levels of serum creatinine and plasma TNF-a were highly significantly increased in the diabetic untreated group but the levels of serum creatinine and plasma TNF-a were significantly reduced in the diabetic group treated with enalapril and pyridoxamine. The level of MDA was significantly increased, whereas the levels of SOD, CAT, and GSH were significantly decreased in the kidneys of the diabetic untreated group; however, the level of MDA was decreased, whereas levels of SOD, CAT, and GSH were increased in the diabetic group treated with enalapril and pyridoxamine. Kidney histopathology of streptozotocin in diabetic rats showed pathological changes. However, treatment with enalapril and pyridoxamine attenuated the histopathological changes and corrected the biochemical parameters mentioned above.
Conclusion
Diabetic nephropathy is one of the most frequent and serious complications of diabetes mellitus. Enalapril and pyridoxamine have renoprotective effects, which have been shown to inhibit structural and functional aspects of diabetic nephropathy and attenuate oxidative stress involved in the streptozotocin diabetic kidney.
|
