高功率微波对大鼠下丘脑和垂体中糖皮质激素受体影响

目的探讨高功率微波（high power microwave，HPM）辐照后下匠脑与垂体中糖皮质激素受体（glucocorticoid receptor，GR）的变化及其意义。方法采用2～90mW／cm^2的HPM辐照130只二级雄性Wistar大鼠，分别于照后6h、1、3、7、14d、28d与3月活杀动物，取下丘脑与垂体，采用免疫组化和图像分析技术研究GR在辐照后大鼠下丘脑与垂体中的表达。结果辐照后下丘脑神经元中GR表达减弱。10mW／cm^2组在6h与1d时较对照组有显著下降（P〈0．05），7d后呈恢复趋势；50mW／cm^2绀在1d时有显著下降（P〈0．05）。辐照后垂体远侧部内分泌细胞GR表达增强。10mW／cm^2组在6h时有显著升高（P〈0．01），7d后呈恢复趋势；50mW／cm^2组在1、3d时均有显著升高（P〈0．01）。结论一定功率密度的HPM辐照后，下丘脑GR表达下降；垂体GR表达增强；HPA轴负反馈调控紊乩；表明GR参与rHPM辐照后下丘脑．垂体．肾上腺轴病变的病理生理过程。

Effects of HPM irradiation on expression of GR in hypothalamus and pituitary gland of rats

Objective To explore the expression and significance of glucocorticoid receptor (GR) in hypothalamus and pituitary gland of rats after high power microwave(HPM) exposure. Methods A total of 130 male Wistar rats were sacrificed at 6 h, 1 d, 3 d, 7 d, 14 d, 28 d and 3 m after whole body irradiation by 2_90 mW/cm 2 HPM and their hypothalamus and pituitary gland were collected. The changes of GR in the two tissues after HPM exposure were investigated by means of immunohistochemical staining and image analysis. Results The expression of GR in hypothalamus was decreased after HPM exposure. The level of GR in the group of 10 mW/cm 2 was significantly lower(P<0.05)than that in the sham exposure group at 6 h and 1 d, and revealed a tendency towards recovery after 7 d. GR in the 50 mW/cm 2 group was significantly lower(P<0.05)on 1 d. The expression of GR in anterior pituitary was increased after HPM exposure. GR in the 10 mW/cm 2 group was significantly higher(P<0.01)at 6 h and revealed a tendency towards recovery after 7 d. GR in the 50 mW/cm 2 group was significantly higher (P<0.01)on 1 d and 3 d after HPM exposure. Conclusion The expression of GR in hypothalamus was decreased while that in the anterior pituitary was increased after HPM exposure.The refore,the negative feedback of hypothalamic-pituitary-adrenal (HPA) axis was upset and the changes of GR is involved in the pathophysiological course of HPA.