Abstract

The concentrations of cadmium, metallothionein(MT), superoxide dismutase(SOD), and lactate dehydrogenase(LDH) were investigated in liver and kidney of rats which were fed the water containing 50 or 100ppm cadmium chloride with basal diet(group A), 5% horsetail diet(group, B), 5% mugwort diet(group C) and 5% champignon diet(group D) for weeks. Cadmium in liver decreased for the first 12 weeks of treatment, but thereafter increased, and was lower in experimental group B,C,D than in control group A. Cadmium in kidney increased linearly during the 16 weeks of treatment, and was lower in group B than in group A. MT in liver decreased for the first 12 weeks of treatment in group A, but increased linearly during the 16 weeks in group B,C,D, higher in group B than in group A. There were significantly higher accumulation of cadmium and MT in liver than in kidney in the beginning of cadmium treatment, but reversed in the ending of treatment. The SOD and LDH activities were not affected during the 16 weeks treatment, and there was no significant difference between groups. Histologic examination revealed moderate to severe hepatic and renal injury in group A compared to horsetail diet group B. These results indicate that the kidney is a major target organ of chronic cadmium poisoning, and suggest that Cd-induced hepatic injury, via release of Cd-MT, may play an important role in the nephrotoxicity. In addition, higher MT concentrations in liver and kidney in the group B constitute a plausible explanation of the protective effects of horsetail diet against the cadmium toxicity in relation to histologic findings.

Keywords

• Cadmium;
• Diet;
• Metallothonein;
• SOD;
• LDH