Effect of Cadmium Chloride Administration and Restraint Stress on Kidney Antioxidants in Female Wistar Rats

Heavy metals, such as cadmium, are toxic, and the kidney is one of their major target organs. Restraint stress, on the other hand, is a model of chronic stress used to mimic human psychological stress. This study aimed to evaluate the effects of restraint stress and cadmium administration on kidney antioxidants in female Wistar rats. 24 female Wistar rats (180-220 g) were randomly divided into 4 groups (n=6): Control (CTL), Restraint stress alone (RSS), Cadmium alone (CCC), Cadmium + Restraint stress (RSC). Body weights of all the rats were monitored. The experimental groups were subjected to cadmium chloride 100 mg/kg orally and restraint stress for 30 minutes daily using wire mesh for 21 days. Twenty-four hours after the last cadmium chloride and restraint stress exposure, all rats were anesthetized and sacrificed. The kidneys were excised, homogenized and analyzed for antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase), lipid peroxidation (Malondialdehyde). The result obtained showed a significant (p˂0.05) decrease in the renal Superoxide dismutase, body weight in Restraint stress alone and Cadmium alone groups when compared to Control. There was a significant (p˂0.05) decrease in the renal catalase in Cadmium group when compared to control. In renal glutathione peroxidase, there was a significant (p˂0.05) decrease in Restraint stress alone and Cadmium alone groups when compared to Control. Furthermore, there was a significant (p˂0.05) increase in malondialdehyde in Restraint stress alone and Cadmium alone groups when compared to Control. Also, malondialdehyde showed a significant (p˂0.05) increase in Cadmium + Restraint stress group when compared to both Restraint stress alone and Cadmium alone groups. Nitric oxide was significantly (p˂0.05) decreased in Cadmium alone group when compared to Control. This study concludes that kidney exposure to cadmium and restraint stress decreased body weight and antioxidant defense capacity, increased lipid peroxidation which may result into adverse renal effects.