X射线全身照射对小鼠免疫功能的影响

摘要

目的:通过X-射线体外全身照射BALB/c小鼠建立小鼠辐射损伤模型,检测放射线对小鼠脾组织、单核巨噬细胞及T、B淋巴细胞损伤的剂量范围,探索放射线剂量与组织损伤程度之间的量效关系.方法:采用9种不同剂量的X-射线体外全身照射BALB/c小鼠,于照射后1d、60d、120d取腹腔细胞做大吞噬实验;分离脾细胞,MTT法检测T细胞增殖活性,同时取脾脏组织切片、HE染色,检测组织损伤程度;照射后120d取小鼠脾细胞用流式细胞仪检测T、B细胞数量百分比.结果:不同剂量X-射线照射的小鼠其大吞噬细胞的吞噬指数及T细胞的增殖指数之间均存在差异,且与放射剂量呈负相关性.FCM检测结果显示0.1Gy及以上剂量组与正常对照组相比较,小鼠T、B淋巴细胞数量减少(P<0.05).0.25Cy和0.5Gy组T、B淋巴细胞数量明显高于除0.05Gy以外的其余各照射组,但是仍低于正常组(P<0.05).脾组织切片显示,照射后1d 0.1Gy以上照射组脾脏炎性细胞浸润;60d后,4.0Gy和8.0Gy组脾脏明显萎缩、巨噬细胞增生、瘤样变,其余组损伤不明显;120d后8.0Gy组脾脏萎缩、红白髓分界不清,白髓损伤尤为严重,其余组不明显.结论:0.1Gy以上X-射线体外全身照射可引起小鼠免疫功能及组织损伤,且损伤程度与放射性强度呈剂量依赖性.%ObjectiVe This study was designated to establish a radiation damage model by whole-body irradiation of different does of X-rays, and to explore dose-effect relationship between radiation and tissue damage.Methods The BALB/c mices's was whole-body irradiation.Peritoneal fluid was collected to do the big englobement experiment and the T cells in the spleen was isolated to assess their proliferation by MTT assay.The spleen were observed by HE stain at the 1 day, 60 day and 120 day and the percentage of T and B lymphocyte in spleen cells were detectde by flow cytometry after 120 days of the ending radiation.Results The phagocytic index of mac-rophagocyte and the T cells proliferation index in each groups were negative correlation with the radiation dosage, flow cytometry showed there were no difference between the 0.05Gy X-ray group and the control group, while the dosage was more than 0.1Gy, the T and B cells was decreased(P <0.05) .The amount of T and B cells in dosage group of 0.25Gy and 0.5Gy was lower than control group, but higher than 0.05Gy group(P <0.05).The histological section showed inflammatory cell infiltrated in 0.1Gy group after ld.After 60 days, the 4.Ogy and 8.Ogy group showed atrophy and macrophage proliferation, tumor-like change in spleens.After 120 days, the spleen was atrophy, the dividing line between red pulp and white pulp was vague in 8Gy group.Condution X-rays above 0.1Gy could lead to immunne function and tissue damage by whole-body irradiation, and the degree of damage was positively correlated with radiation strength.