The health risks to humans from acute and chronic cadmium (Cd) exposure have been well documented. The kidney is considered the critical organ for Cd toxicity following long-term exposure in humans and experimental animals. There is considerable information in the literature regarding the protective effect of Zn against the cellular toxicity caused by Cd. The present study was undertaken to examine the morphological alterations of the kidney after cadmium exposure, and to evaluate the potential benefit of Zn co-treatment on cadmium-induced tissue injury. Thirty male albino rats were divided into three groups. The first (control) group was injected subcutaneously with normal saline, the second group was injected subcutaneously with cadmium chloride solution (2.5 mg/kg b.w) 5 days/week for six weeks, and the third group was injected with zinc chloride solution (2.2 mg/kg b.w) one hour before the dose of cadmium chloride, 5 days/week for six weeks.
Histological, histochemical and ultrastructural investigations of the kidney tissue confirmed the damaging effects of cadmium and revealed the beneficial effects of zinc pre-treatment on Cd-induced structural damage.