失重对大鼠肾上腺髓质激素分泌及miRNA-375表达的影响  

Effect of simulated null gravity on the secretion of adrenomedullary hormones and miRNA-375 expression in rats

作　　者：温丽君[1] 吴继华[2] 宋淑军[3] 王艳茹[2] 刘俊丽[3] 司少艳[3] 崔彦[4] 张建中[2] 周金莲[1,2] 

机构地区：[1]安徽医科大学解放军306医院临床学院,北京100101 [2]解放军306医院病理科 [3]解放军306医院特种医学实验研究中心 [4]解放军306医院普通外科

出　　处：《解放军医学杂志》2015年第4期322-326,共5页Medical Journal of Chinese People's Liberation Army

基　　金：全军医学科研"十二五"重点项目(BWS11J051)~~

摘　　要：目的研究模拟失重环境对大鼠肾上腺髓质激素分泌及miRNA-375表达的影响。方法健康成年雄性Wistar大鼠56只,随机分为0h（正常对照）、6h、12h、1d、3d、5d、7d共7个组（n=8）。采用Morey-Holton尾悬吊法建立模拟失重动物模型。各组大鼠实验结束后眼球取血,取双侧肾上腺。采用放射免疫分析法检测血浆肾上腺髓质激素[多巴胺（DA）、去甲肾上腺素（NE）、肾上腺素（E）]水平,RT-PCR法检测肾上腺组织酪氨酸羟化酶（TH）mRNA和miRNA-375的表达,Western blotting和免疫组化技术检测肾上腺髓质TH蛋白表达。结果尾悬吊模拟失重条件下大鼠血浆肾上腺髓质激素波动明显,6~12h出现一过性下降,随后急剧升高,3d时形成峰值。RT-PCR结果显示,各组大鼠肾上腺组织TH mRNA表达波动明显,6h时呈现一过性下降,随即上升,1d时达峰值,之后呈下降趋势,5d时形成谷值。大鼠肾上腺髓质TH蛋白表达以尾悬吊3d时染色最强。肾上腺髓质中miRNA-375表达表现为尾悬吊早期（6h）呈一过性显著升高,随后快速下降,12h、1d和3d时表达受到明显抑制,表达量显著下降,5d时表达量增加,7d时显著升高（P〈0.05）。结论失重环境可影响大鼠肾上腺髓质激素分泌,其机制可能与miRNA-375通过复杂的信号通道调控TH表达有关。Objective To investigate the effects of simulated null gravity on the secretion of adrenomedullary hormones and miRNA-375 expression in rats. Method Fifty-six healthy adult male Wistar rats were randomly divided into 7 experimental groups（8 each）, including suspension for 6h, 12 h, 1d, 3d, 5d, 7d and 0h（control）. Tail-suspension was used to establish the weightlessness animal model according to Morey-Holton＇s method. At the end of the experiment, the blood samples were obtained from the postorbitor vein, and the bilateral adrenal glands were harvested. The serum concentrations of catecholamines were determined by radioimmunological analysis. The expression of TH mRNA and miRNA-375 were assessed by quantitative RTPCR. TH protein in adrenal medulla was assayed using Western blotting analysis and immunohistochemistry. Results（1） The serum concentrations of rat＇s adrenomedullary hormones fluctuated obviously during the period of tail-suspension simulated weightlessness, with a temporary decline during 6-12 h, followed by a sharp increase with a peak value on the 3rd day of suspension.（2） RT-PCR assay showed that TH mRNA expression in adrenal medulla of rats also fluctuated obviously, with a temporary decline at 6h and then elevated with a peak value at 1 day of suspension, followed by a downward trend forming a trough value on 5d of suspension. The immunohistochemistry showed that TH protein was stained as brown particles and the cytoplasm of adrenal medulla was stained deeply on 3d of suspension.（3） RT-PCR assay revealed that the expression of miRNA-375 in adrenal medulla increased temporarily at 6h of suspension, and it decreased significantly during 12 h to 3d of suspension compared with that of control group（P〈0.05）. The miRNA-375 expression was up-regulated again during sustained suspension with a significant increase on 7d of experiment compared with that of control group（P〈0.05）. Conclusion The simulated weightlessness could affect the secretion of hormone of adrenal medulla

关 键 词：失重模拟 儿茶酚胺类 酪氨酸羟化酶 微RNAS 

分 类 号：R855[医药卫生—航空、航天与航海医学]