多次低剂量X线照射对小鼠睾丸组织形态及生精细胞P53和bcl-2蛋白表达的影响

Effects of repeated low-dose X-ray irradiation on histomorpholo- gical changes of testis and the expression of P53 and bcl-2 in spermatogenic cells of mice

目的探讨多次低剂量X线照射对小鼠睾丸组织形态及生精细胞P53和bcl-2蛋白表达的影响。方法采用0、0．025、0．075及0．1GyX线多次照射小鼠，以HE染色观察睾丸生精小管形态结构，免疫组织化学法测定生精细胞中P53及bcl-2蛋白的表达水平。结果随着单次低剂量X线照射剂量增加，HE染色结果显示照射组小鼠睾丸出现生精小管各级生精细胞数目逐渐减少，结构排列紊乱等不同程度的组织病理改变；免疫组织化学可见生精细胞中P53蛋白表达水平逐渐增加，而bcl-2蛋白表达水平则逐渐下降。结论低剂量X线多次全身照射可引起小鼠睾丸组织病理改变，并上调生精细胞P53蛋白、下调bcl-2蛋白表达水平，从而诱导凋亡。

Objective To investigate the effects of low-dose X-ray radiation on the testlcular nlstomorpnology and the expressions of P53 and bcl-2 protein in mouse spermatogenic cells. Methods Mice were exposed to repeated irradiation by 0, 0.025, 0.075 and 0.1Gy X-ray respectively. The morphology of testicular seminiferous tubules was observed using Hematoxylin-Eosin（HE） staining and the expressions of P53 and bcl-2 protein in germ cells were detected by immunohistochemistry. Results HE staining showed that the number of sperrnatogenic cells was gradually decreased in irradiated seminiferous tubules of mice testis and structural arrangement was destoryed in varying degrees in parallel with increase of single low-dose X-ray radiation dose .Immunohistochemical staining showed that the expression of P53 gradually was increased whereas the bcl-2 protein level was decreased in spermatogenic cells as increase of the single low-dose X-ray radiation dose. Conclusion Repeated low-dose X-ray irradiation might injury the histomorphology of testis, upregulate the expression of P53 and downregulate expression of Bcl2 in the rat testes, which may further induce germ cell apoptosis.