1.5 GHz微波辐射对大鼠外周血免疫细胞和脾脏组织影响的量效关系研究

The dose-effect relationship of 1.5 GHz microwave radiation on peripheral blood immune cells and spleen tissue in rats

目的探讨不同平均功率密度的1.5 GHz微波辐射对大鼠外周血免疫细胞数量和亚群、细胞因子以及脾脏等组织结构的影响,明确1.5 GHz微波辐射对大鼠免疫系统的损伤效应和量效关系。方法二级雄性Wistar大鼠(180±20)g,80只,随机分为4组:假辐射组(Sham)和3个辐射组(L5、L30和L50)。采用1.5 GHz微波,平均功率密度分别为0、5、30和50 mW/cm^(2),辐射时间为6 min。辐射后6 h、7 d和14 d,采用戊巴比妥钠溶液腹腔注射麻醉大鼠,经腹主静脉采集外周血,分别采用血细胞计数仪检测外周血中免疫相关细胞的数量;采用流式细胞仪检测淋巴细胞亚群(B淋巴细胞、T淋巴细胞和NK细胞等)的比例;收集并分离外周血血清,采用多功能液相芯片分析平台检测细胞因子浓度,包括IL-2、IL-4、IL-6、IL-17A、肿瘤坏死因子α(tumor necrosis factorα,TNF-α)的浓度。采用光镜观察脾脏和骨髓的组织结构,透射电镜观察脾脏超微结构。结果与假辐射组相比,各微波辐射组大鼠外周血淋巴细胞数量于辐射后6 h显著下调(P<0.05),于辐射后14 d基本恢复。辐射后6 h的L30组和L50组、辐射后7 d和14 d的L50组,大鼠外周血中B淋巴细胞比例显著上调(P<0.001),T淋巴细胞比例明显下调(P<0.001);辐射后6 h和7 d,L30组和L50组大鼠血清IL-2、IL-4、IL-6、IL-17A、TNF-α等细胞因子释放增多(P<0.05)。微波辐射后7 d,大鼠脾脏组织可见血管淤血、淋巴细胞核碎裂等,损伤程度与平均功率密度呈正相关,骨髓组织结构未见明显改变。结论1.5 GHz微波辐射可剂量依赖性引起大鼠外周血免疫细胞紊乱和脾脏组织损伤。外周血淋巴细胞亚群和细胞因子释放异常,可能是机体调节免疫平衡及改善损伤修复的途径之一。

Objective To investigate the effects of 1.5 GHz microwave radiation with different average power densities on the number and subpopulation of immune cells and cytokines in the peripheral blood,as well as the spleen structure of rats and clarify its damage effect and dose-effect relationship on the immune system of rats.Methods Eighty secondary male Wistar rats(180±20)g were randomly divided into four groups of sham radiation group(Sham)and three radiation groups(L5,L30 and L50).The 1.5 GHz microwaves for the radiation duration of 6 min were applied at the average power densities of 0,5,30 and 50 mW/cm^(2),respectively.The rats were anesthetized by intraperitoneal injection of sodium pentobarbital solution at 6 h,7 d and 14 d after radiation.The peripheral blood was collected via the main abdominal vein to detect the number of immune-related cells using a hemocytometer.The ratio of lymphocyte subpopulation(B lymphocytes,T lymphocytes and NK cells,etc.)was measured with flow cytometry.The peripheral blood serum was collected and separated.The level of cytokines in serum,including interleukin(IL)-2,IL-4,IL-6,IL-17A,tumor necrosis factorα(TNF-α)were measured by multifunctional liquid phase chip analysis platform.The histological structures of the spleen and bone marrow were observed with pathological staining and light microscopy.The ultrastructure of the spleen tissues was observed with scanning electron microscopy at 7 d after radiation.Results As compared to the sham group,the number of lymphocytes in peripheral blood was decreased at 6 h after radiation(P<0.05)and gradually recovered at 14 d after exposure in three radiation group.The proportion of B lymphocytes in peripheral blood was significantly increased(P<0.001)and the proportion of T lymphocytes was significantly down-regulated(P<0.001)in the L30 and L50 groups at 6 h after radiation,and in the L50 group at 7 and 14 d after radiation.The release of IL-2,IL-4,IL-6,IL-17A,and TNF-αwere increased(P<0.05)in the L30 and L50 group at 6 h and 7 d after radiation.The vascular bruising and lymphocyte nuclei fragmentation were showed in the spleen tissue of rats,and the degree of damage was positively correlated with the average power density.There was no significant change in bone marrow tissue structure at 7 d after microwave radiation.Conclusion 1.5 GHz microwave could dose-dependently cause disorders in the number of immune-related cells in peripheral blood and damage in spleen tissue of rats.Abnormalities in peripheral blood lymphocyte subpopulation and cytokine release might be the way for the body to regulate immune homeostasis and improve damage repair.