Restorative Effects of Zinc and Selenium on Cadmium-induced Kidney Oxidative Damage in Rats

Objective To investigate whether cadmium-induced oxidative stress in the kidney isinfluenced by zinc and selenium. Methods Five groups of rats were maintained: (A) Cd (CdCl2,400 mg·kg-1·day-1 intraperitoneal injection); (B) Cd+Zn (ZnCl2, 20mg. kg-1·day-1 hypodermicinjection); (C) Cd+Se (Na2SeO3, 350 mg·kg-1·day-1 via a stomach tube); (D) Cd+Zn+Se; (E)treated with physiological saline as a sham-handled control. The rats were given treatmentfor a period of 4 weeks. The activities of superoxide dismutase (SOD), glutathione peroxidase(GH-Px), catalase (CAT), and the level of malondialdehyde (MDA) in the kidney tissue weremeasured to assess the oxidative stress. Urinary lactate dehydrogenase (LDH) activity wasused as an indicator of tubular cell damage caused by lipid peroxidation. Results In groupC and D, activities of SOD (110.5±5.2, 126.8±7.0; P < 0.05) and GSH-Px (85.7±4.9,94.6±7.3; P < 0. 05) were higher than those in group A(84.7±3.3; 56.9±3.8); and in groupB, only the activity of GSH-Px (80.0±4.3, P < 0.01) increased in comparison with that ingroup A (56.9±3.8). Significant increase of MDA (P < 0.05) was seen in group B (31.1±4.7) andC (35.0±4.1) when compared with control values (17.2±1.8). No difference was found inthe level of MDA between group D (18.9±2.6) and control. The activity of LDH in urineof control group (0.06±0.02) was lower than that of group A (0.46±0.19, P<0.05), B (0.10±0.05, P<0.05) and C (0.14±0.07, P<0.05), and there was no significant change betweencontrol (0.06±0.02) and group D (0.08±0.02). Conclusion Zinc or selenium couldpartially alleviate the oxidative stress induced by cadmium in kidney, but administrationcadmium in combination with zinc and selenium efficiently protects kidney from cadmium-induced oxidative damage.