Morphological alterations of spleen with low level of lead exposure in mice

Objective: To observe the effect of low level lead exposure on the morphological alterations of spleen in mice.Methods: The experimental mice were divided into five groups,which had been oral fed with different concentrations of lead acetate(the 0.025%,0.05%,0.075%,0.1%group) or distilled water(the control group) for 8 weeks respectively.The structural alterations of spleen in mice were observed by light microscope.Results: The structures of spleen had hardly any alternations between the 0.025% group and the control group.On the contrary,the morphological structure of spleens in the 0.05%,0.075% and 0.1% groups could be observed as follows: The white pulp did not well develop,the number of splenic nodules decreased evidently,no germinal center could be found clearly.In addition,the lymphocytes in peripheral lymphatic sheath were sparse and no clear boundary could be determined between white pulp and red pulp.Conclusion: The results suggested that low level of lead exposure inhibit immune system in mice.