Evaluation of genotoxic damage of cadmium chloride in peripheral blood of suckling Wistar rats

The aim of this study was to evaluate possible genotoxic damage of cadmium chloride exposure in suckling rats by means of the comet assay and the in vivo micronucleus test of rat blood lymphocytes, because no information is available on the genotoxic effect of cadmium in rats at this early age. Pups were receiving cadmium (as CdCl(2).H(2)O) orally in fractions of 0.5 mg for 9 days, totalling 4.5 mg Cd kg(-1) body wt, or were given a single subcutaneous injection of 0.5 mg Cd kg(-1) body wt. Some pups in both exposed groups were receiving calcium supplement (CaHPO(4).2H(2)O) in feed to reduce the body load of cadmium. Control pups did not receive either cadmium or calcium supplement. Cadmium in the carcass and organs was measured by atomic absorption spectrometry. The results showed that the cadmium body burden was significantly lower when the animals were receiving calcium supplements along with oral cadmium. The results of the micronucleus and comet assays showed significant differences between the control and exposed groups, regardless of the route of cadmium administration. The only statistically significant difference between the two exposed groups (oral cadmium and oral cadmium + calcium supplements) was in the number of micronuclei. The results of the comet assay showed that tail length differed statistically only between the control and all exposed groups, regardless of the route of cadmium administration. It can be concluded that the applied cadmium doses caused detectable genome damage but it was lower in calcium-treated pups receiving cadmium orally.