目的 探讨 SD大鼠重型颅脑损伤(STBI)后β2 受体转录水平对肺损伤相关因素的影响.方法 将 24只清洁型雄性 SD大鼠按随机数字表法分为正常组(n=6)和 STBI组(n=18);制作 STBI大鼠模型.STBI组在伤后第 1 ,2 ,7 天各处死 6 只动物进行观察.用光镜观察肺组织形态学改变;PCR 定量检测肺组织β2 受体的转录水平,Elisa法检测支气管肺泡灌洗液(BALF)中肺损伤相关炎性因子TNF-α和 IL-6 的水平.结果 光镜下大鼠STBI组各时相均可见肺毛细血管充血、炎性细胞渗出及肺间质增厚等病理改变,且肺组织病理学改变进行性加重;各组间肺组织病理学评分比较差异具有统计学意义(F=68.520,P﹤0.01),对各时间点两两比较,肺组织病理评分进行性增高,于 STBI第 7 天达最高(P﹤0.05).大鼠肺β2 受体转录水平在各时相点均明显低于正常组(P﹤0.05 ),第 1 天时达最低值(P﹤0.05),大鼠肺BALF中 TNF-α水平在各时相点均明显高于正常组(P﹤0.05),第 1 天时达到峰值(P﹤0.05);IL-6 水平在各时相点均明显高于正常组(P﹤0.05 ),第二天时达到峰值(P﹤0.05 ).相关分析显示,肺组织β2 受体转录水平与TNF-α、IL-6 含量第 1 ,2 ,7 天三个时间点均呈负相关.结论 大鼠 STBI后有急性肺损伤的表现,损伤程度随着时间的延长而进行性加重,炎性因子TNF-α、IL-6 参与其过程.炎性级联反应的爆发导致肺β2 受体转录水平下降、肺保护功能减低可能是加重肺损伤的重要因素.%Objective To study on severe traumatic brain injury in SD rats(STBI)and the effect of post β2 receptor transcriptional level on the related factors of lung injury.Methods Twenty-four male SD rats were divided into normal group(n=6)and STBI group(n=18)according to random digital table method.Preparation of STBI rat model.STBI group after injury 6 animals were killed after 1,2,7 days.The morphologic changes of lung tissue were observed by light microscope.Detection the levels of bronchoalveolar lavage fluid (BALF)of inflammatory factors TNF-α and IL-6 were associated with lung injury by Elisa,and the transcriptional level of β2 receptor was detected by quantitative PCR. Results The pathological changes of pulmonary capillary congestion,inflammatory cell exudation and pulmo-nary interstitial thickening were observed in STBI group under light microscope,and the pathological changes of lung tissue were gradually aggravated.There werestatistical significantlydifferences of lung histopathological score a-mong groups (F=68.520,P﹤0.01). Compared with each other at each time point,the pathological score of lung tissue increased progressively and reached the highest level on day 7th of STBI (P﹤0.05).The transcriptional level of β2 receptor was significantly lower than the normal group at all time points(P ﹤0.05)To the lowest value at 1d (P﹤0.05). The level of TNF-α in Balf of rat lung was significantly higher than the normal group(P﹤0.05)and reach a peak at 1 d(P﹤0.05). The level of IL-6 was significantly higher in each time phase than that in normal group(P﹤0.05)and reach a peak at 2 d(P﹤0.05).The related analysis showed that the content of TNF-α and IL-6 was negatively correlated with the three time points of 1 d,2 d and 7 d at the β2 receptor transcriptional lev-el.Conclusion In rats with acute lung injury after STBI,the degree of injury increased with time.Inflammatory cyto-kines TNF-α and IL-6 can induce acute lung injury after STBI in rats by activating systemic inflammatory cells.At the same time,the increase of TNF-αand IL-6 inhibited the transcription of the β2 receptor gene,which reduced the density of the β2 receptor in lung tissueand may also have a relationship with the occurrence of acute lung injury after STBI in rats.
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