The Different Responses of Some Adult Albino Rats’ Body Organs to the Genotoxic Effect of Cadmium

Cadmium (Cd) is one of the most toxic environmental pollutants affecting the DNA. Cadmium interferes with DNA repair process and induces oxidative stress leading to DNA damage. Since the most recent molecular cancer genetic and cytogenetic data have provided strong evidence that genetic damage can be the initial step of the malignant process, the early detection of DNA-damaging effect of Cd in different organs is very important to avoid its carcinogenic potential .Hence, this study was undertaken to determine the response of some different rat organs to the genotoxic effect of Cd. The study was conducted on 48 adult male albino rats divided into three main groups; group I (negative control group) consisted of 15 rats, group II (positive control group) consisted of 15 rats, received 1 ml distilled water daily by gavage and group III (cadmium group) consisted of 18 rats, received cadmium chloride in a dose of 5 mg/kg body weight daily by gavage. Each one of these three main groups was subdivided according to the experimental period into three equal subgroups; (a), (b), and (c). The experimental period was two weeks for subgroups Ia, IIa, and IIIa, four weeks for subgroups Ib, IIb, and IIIb and eight weeks for subgroups Ic, IIc, and IIIc. Determination of possible DNA damage using comet assay in lymphocytes, bone marrow (BM), lung, liver, and kidney along with malondialdehyde and Cd levels were carried out. The results of this study revealed a heterogeneous response of the studied organs to the genotoxic effect of Cd. Lymphocytes and BM were early affected while the liver showed the highest genetic damage with longer exposure period. These findings suggest that lymphocytes and BM are more sensitive to Cd genotoxicity than the lung, liver, and kidney. So lymphocytes and BM can be used as early determinants of Cd-induced genetic damage. Considering these issues, health educational programs should be implemented to highlight the dangerous impact of Cd on health. Moreover, persistence of this metal in the environment requires a long-term move towards minimizing human exposure through environmental management and preservation of lower Cd levels wherever possible. Also, further studies are needed to detect the genotoxicity of Cd in other organs.