S波段高功率微波对大鼠下丘脑垂体肾上腺轴的功能及形态影响

Effects of S band HPM radiation on function and morphology of hypothalamus-pituitary-adrenal axis in rats

目的:探讨S波段高功率微波(HPM)辐射对大鼠下丘脑垂体肾上腺轴(HPA)功能与结构的影响.方法:采用2～90 mW/cm2 的S波段HPM辐照130只二级雄性Wistar大鼠,分别于照后6 h,1 d,7 d,14 d,28 d及3个月活杀,取血、肾上腺、垂体及下丘脑.采用放射免疫法检测血清中相关激素的变化,采用光镜(HE、TB、Peace和Agnor染色)、电镜和图像分析技术,定量研究上述组织损伤的形态变化.结果:S波段HPM辐照后,内分泌功能发生改变,表现为血清中皮质醇(CS)下降、促肾上腺皮质释放激素(ACTH)与生长激素(GH)升高.辐照后HPA轴各器官均见组织损伤,肾上腺束状带实质细胞、垂体远侧部细胞及下丘脑神经元见变性与坏死;肾上腺束状带细胞嗜银蛋白减少而腺垂体细胞嗜银蛋白增加;腺垂体嗜碱细胞颗粒呈升高趋势;下丘脑神经元尼氏体减少.上述改变呈现一定的剂量相关性.结论:S波段HPM辐照可引起HPA轴各器官功能与结构改变,且此改变呈一定剂量效应关系.

Objective:To explore the functional and morphological changes of hypothalamus-pituitary-adrenal axis in rats after S band high power microwave(HPM) exposure. Methods:One hundred and thirty male Wistar rats were sacrificed at 6 h, 1 d, 3 d, 7 d, 14 d, 28 d and 90 d after whole-body irradiation by 2-90 mW/cm 2 S band HPM. Their hypothalamus, pituitary, adrenal and blood samples were collected. Radioimmunoassay was used to measure the levels of adrenocorticotropic hormone(ACTH),growth hormone(GH) and cortisol(CS) in serum.Their morphological changes were observed with optical microscope (HE,TB,Peace,Agnor staining), electron microscope and image analysis. Results:The serum level of CS was significantly lower after exposure to HPM than the sham exposure, while the levels of GH and ACTH demonstrably higher after HPM exposure. Morphological observations showed the injurious changes of these tissues. Degeneration, necrosis and apoptosis could be noted in parenchymatous cells within zona fasciculata of adrenal gland, and in the anterior pituitary and hypothalamus. The content of Agnor protein in zona fasciculata decreased while that in anterior pituitary increased;granules of basophilic cells within anterior pituitary revealed a tendency towards increase; the content of Nissl bodies in hypothalamus decreased,and the above changes were dose-dependent. Conclusion: S band HPM can cause changes in the function and morphology of hypothalamus-pituitary-adrenal axis, and the changes are dose-dependent.