摘要
目的评价右美托咪定预先给药对大鼠肠缺血再灌注时Toll样受体4(TLR4)/NF-κB信号通路的影响。方法雄性SD大鼠24只,体重180~220 g,采用随机数字表法分为3组(n=8):假手术组(S组)、肠缺血再灌注组(I/R组)和右美托咪定预先给药组(DP组)。采用夹闭大鼠肠系膜上动脉1 h、恢复灌注2 h的方法建立肠缺血再灌注损伤模型。DP组于缺血前30 min腹腔注射右美托咪啶100 μg/kg。再灌注2 h时采集大鼠心脏血样,采用ELISA法检测血清肠型脂肪酸结合蛋白(I-FABP)水平;取小肠组织,光镜下观察病理学结果并进行Chiu评分,采用ELISA法检测肠组织TNF-α和IL-1β的含量,采用Western blot法测定肠组织总蛋白TLR4、MyD88、磷酸化NF-κB p65(p-NF-κB p65)以及核蛋白NF-κB p65的表达水平。结果与S组相比,I/R组大鼠肠黏膜Chiu评分、血清I-FABP浓度、肠组织TNF-α和IL-1β的含量升高,肠组织总蛋白TLR4、MyD88、p-NF-κB p65以及核蛋白NF-κB p65表达上调,DP组肠黏膜Chiu评分升高,肠组织MyD88和p-NF-κB p65表达上调(P<0.05),血清I-FABP、肠组织TNF-α和IL-1β的含量、总蛋白TLR4和核蛋白NF-κB p65的表达差异无统计学意义(P>0.05);与I/R组相比,DP组大鼠肠黏膜Chiu评分、血清I-FABP浓度、肠组织TNF-α和IL-1β的含量降低,肠组织总蛋白TLR4、MyD88、p-NF-κB p65以及核蛋白NF-κB p65表达下调(P<0.05)。结论右美托咪定预先给药减轻大鼠肠缺血再灌注损伤的机制可能与抑制TLR4/NF-κB信号通路的激活有关。
Objective To evaluate the effect of dexmedetomidine pretreatment on Toll-like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)signaling pathway during intestinal ischemia-reperfusion(I/R)in rats. Methods Twenty-four male Sprague-Dawley rats, weighing 180-220 g, were divided into 3 groups(n=8 each)using a random number table method: sham operation group(S group), intestinal I/R group(I group)and dexmedetomidine pretreatment group(DP group). Intestinal I/R model was established by occlusion of the superior mesenteric artery for 1 h followed by 2-h reperfusion in anesthetized rats.Dexmedetomidine 100 μg/kg was intraperitoneally injected at 30 min before ischemia in DP group.Blood samples were collected from hearts at the end of reperfusion for determination of the serum intestinal fatty acid binding protein(I-FABP)level by enzyme-linked immunosorbent assay.The intestinal tissues were obtained at the end of reperfusion for examination of pathologic changes and for determination of tumor necrosis factor-alpha(TNF-α)and interleukin-1beta(IL-1β)contents(by enzyme-linked immunosorbent assay)and expression of TLR4, MyD88, phosphorylated NF-κB p65(p-NF-κB p65)in total protein and NF-κB p65 in nucleoprotein(by Western blot). The degree of intestinal tissue damage was graded using Chiu′s scoring system. Results Compared with S group, the Chiu′s score and concentrations of I-FABP in serum and contents of TNF-α and IL-1β in intestinal tissues were significantly increased, and the expression of TLR4, MyD88 and p-NF-κB p65 in total protein and NF-κB p65 in nucleoprotein was up-regulated in I/R group, and the Chiu′s score was significantly increased, the expression of MyD88 and p-NF-κB p65 was up-regulated(P<0.05), and no significant change was found in serum I-FABP concentration, contents of TNF-α and IL-1β, or expression of TLR4 in total protein and NF-κB p65 in nucleoprotein in DP group(P>0.05). Compared with I/R group, the Chiu′s score, serum I-FABP concentration, and contents of TNF-α and IL-1β were significantly decreased, and the expression of TLR4, MyD88 and p-NF-κB p65 in total protein and NF-κB p65 in nucleoprotein was down-regulated in DP group(P<0.05). Conclusion The mechanism by which dexmedetomidine pretreatement mitigates intestinal I/R injury may be related to inhibiting activation of TLR4/NF-κB signaling pathway in rats.
作者
杨静
吴友平
徐岩
郄文斌
邓慧
扶超
屠伟峰
Yang Jing;Wu Youping;Xu Yan;Xi Wenbin;Deng Hui;Fu Chao;Tu Weifeng(Department of Anesthesiology, General Hospital of Southern Theatre Command of The Southern Medical University, Guangzhou 510010, China)
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2019年第1期31-35,共5页
Chinese Journal of Anesthesiology
基金
国家自然科学基金(81501647)
广州市科技计划项目(201804010216).
