热应激对大鼠脑桥臂旁核Fos和GFAP表达的影响

为了探讨急性热应激(heat stress,HS)后大鼠脑桥臂旁核Fos蛋白及胶质原纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达变化,本实验将大鼠置于恒温恒湿温度舱内,舱内温度调至24℃、34℃、38.5℃或42℃、湿度为60%,建立HS大鼠模型,1h后结束刺激,立即断头取脑,应用免疫组织化学染色方法检测脑桥臂旁核内Fos蛋白和GFAP的表达情况。结果显示:脑桥臂旁核内可见大量的Fos样免疫阳性神经元和GFAP样免疫阳性的星形胶质细胞,其中在24℃~38.5℃组Fos蛋白的表达随温度增加而增加,38.5℃组为高峰,而在42℃组Fos蛋白表达又有所减少。GFAP样免疫阳性星形胶质细胞在34℃组出现胞体变大,突起增粗的现象,且细胞数量增加,38.5℃组最显著,但在42℃组星形胶质细胞的数量则有所减少,并出现胞体形态不规则、突起断裂的现象。本实验结果表明脑桥臂旁核参与热应激反应的神经免疫调节,可能为此调节通路的中继站之一。

THE EFFECT OF HEAT STRESS ON FOS AND GFAP EXPRESSION IN THE PARABRACHIAL NUCLEUS OF RAT PONS

To investigate the changes of expression of Fos protein and glail fibrillary acidic protein(GFAP)in the parabachial nucleus(PBN)of rat pons after acute heat stress(HS),the rats were placed within the experimental incubator,with the temperature at 24℃,34℃,38.5℃ or 42℃ and the relatively humidity at 60% to build HS rat model in the present study.One hour later,rats were decapitated and their brains were taken out.Immunohistochemical staining methods were used to detect the expressions of Fos and GFAP in the PBN of the pons.The results showed that many Fos-like immunoreactive(Fos-LI)neurons and GFAP-like immunoreactive(GFAP-LI)astrocytes were distributed in the PBN of the pons.The number of Fos-LI neurons increased with the increase of temperature from 24℃ to 38.5℃.The Fos expression reached a peak at 38.5℃ and then decreased at 42℃.GFAP-LI astrocytes appeared the cell bodies hypertrophied,processes thicken and number increase at 34℃,peaked at 38.5℃.While at 42℃,the number of astrocytes decreased significantly,the shape of their bodies was anomalism and processes were broken.The present results indicate that PBN of pons is involved in the neuroimmunity modulating to heat stress and it maybe is one of relay station of this regulated pathway.