OBJECTIVETo study the effects of electromagnetic pulses (EMP) on pathological changes and apoptosis of spleen lymphocytes in mice.

METHODSThe male BALB/c mice (18 ∼ 22 g) were sham-exposed or exposed to EMP at 200 kV/m for 400 pulses a day for 7 days. On the 1st, 3rd, 7th, 14th 28th days after exposure the mice were killed. The weight of mice, the pathological change and the weight of mouse spleens were observed, the spleen indexes were calculated. The lymphocytes extracted from spleens were counted. The apoptosis and cell cycle of the lymphocyte were detected by flow cytometry, and the migration of the lymphocyte was measured by transwell assay.

RESULTSNo pathological changes were found on the first day after exposure. However, the expanded sinusoid and the changed structure of spleen corpuscle on the 3rd day after exposure were observed. There was no difference of spleen indexes between the sham group and the exposure group on the 1st and 14th day after exposure. On the 3rd and 7th days after exposure, the spleen indexes of exposure group were significantly higher than those of sham-exposure group (P < 0.05). On the 28th day after exposure, the spleen indexes of exposure group was significantly lower than those of sham-exposure group (P < 0.05). The number of spleen lymphocytes on the 3rd and 7th days after exposure in exposure group increased significantly, compared with sham-exposure group (P < 0.05). But there were no differences of apoptotic cells and cellular cycle between the exposure group and sham-exposure group (P > 0.05). The ability of migration of the exposure group was significantly higher than that of sham-exposure group (P < 0.05). than the sham group (P < 0.05).

CONCLUSIONThe spleen of the male mouse is one of the target organs of EMP. After exposure to EMP, the number of spleen lymphocytes increased. But there were no differences of cell apoptotic cells and cell cycle between the sham group and the exposure group, due to the enhanced migration of lymphocytes induced by EMP.