多次低剂量辐射对糖尿病大鼠脾脏淋巴细胞亚群的免疫调节作用

目的：观察多次低剂量辐射（LDR）照射后糖尿病（DM）大鼠脾脏淋巴细胞亚群的变化。方法：实验分为正常对照组、DM组和不同剂量LDR组（剂量分别为0.025、0.050和0.075 Gy）。链脲佐菌素（STZ）腹腔注射诱导DM大鼠模型，经15次照射后４周末采用流式细胞术检测脾细胞中CD4⁺、CD8⁺ T细胞百分数及CD4⁺/CD8⁺ T细胞比例。结果：造模1周后，DM组大鼠出现明显的多饮、多食、多尿及体重减轻现象。照射后4周末，与正常对照组比较，DM组大鼠脾脏CD4⁺ T细胞百分数明显增加（P<0.01），CD8⁺ T细胞百分数明显降低（P<0.01），CD4⁺/CD8⁺ T细胞比值明显增加（P<0.001）；不同剂量LDR组淋巴细胞亚群变化均不明显。与DM组比较，0.050和0.075 Gy LDR组CD4⁺ T细胞百分数显著降低（P<0.05，P<0.01），不同剂量LDR各组CD8⁺ T细胞百分数均显著增加（P<0.01），不同剂量LDR各组CD4⁺/CD8⁺ T细胞比值均显著降低（P<0.01）。结论：多次LDR能够调节DM大鼠的免疫功能，纠正其免疫失衡状态，从而达到保护机体的作用。

Effects of multiple low dose radiation on spleen T lymphocyte subgroups in eight-week diabetic rats

Objective To explore the changes of spleen lymphocyte subgroups in diabetic rats after multiple low dose radiation(LDR).Methods The experiment was divided into normal control group,pure diabetes mellitus(DM) group,and DM plus different doses of irradiation groups(the irradiation doses were 0.025,0.050 and 0.075 Gy,respectively).The diabetic rat model was induced by intraperitoneal injection of streptozotocin.After the diabetic rats were irradiated 15 times,the percentages of spleen CD4+ and CD8+ T cells and ratio of CD4+/CD8+ T cells were detected with flow cytometry on the fourth weekend.Results The diabetic rats manifested obvious polydipsia,polyphagia,polyuria and weight loss.On the fourth weekend after irradiation,as compared with normal control group,the percentage of spleen CD4+ T cells increased significantly(P<0.01),and that of CD8+ T cells decreased significantly(P<0.01),and the ratio of CD4+/CD8+ T cells was increased significantly(P<0.01) in diabetic rats;but the changes of spleen lymphocyte subgroups were not significant in LDR plus DM groups.As compared with DM group,the percentages of spleen CD4+ T cells were declined markedly in both 0.050 and 0.075 Gy plus DM groups(P<0.05,P<0.01),and those of CD8+ T cells increased significantly in LDR plus DM groups(P<0.01),and the ratio of CD4+/CD8+ T cells was declined obviously(P<0.01).Conclusion The multiple LDR could regulate the immune function in diabetic rats,and rectificate the immunological imbalance in order to protect body.