大承气汤对脓毒症大鼠高迁移率族蛋白B1表达的影响

Study of the effect of Dachengqi decoction on high mobility group box - 1 in septic rats

目的 通过观察大承气汤对脓毒症大鼠HMGB1表达的影响,进一步揭示大承气汤治疗脓毒症的分子机制.方法 将96只SD大鼠随机分为假手术组、脓毒症组、低剂量大承气汤组（LDT组）、高剂量大承气汤组（DT组）,盲肠结扎穿刺法复制大鼠脓毒症模型.LDT组和DT组分别以不同浓度的大承气汤灌胃,假手术组和脓毒症组以生理盐水对照灌胃.各组大鼠分别于术后2、8、24、48 h四个时间点随机处死6只大鼠,经腹主动脉取血,离心去上清,用ELISA方法检测血浆TNF-α、IL-6、HMGB1的表达.术后24 h,取大鼠末端回肠,用RT-PCR法检测回肠组织HMGB1 mRNA表达,用免疫组织化学方法观察肠组织HMGB1蛋白表达,在光镜下观察大鼠肠组织的病理变化.结果 与假手术组比较,脓毒症组血浆HMGB1在术后8、24、48 h显著增高,脓毒症组回肠组织HMGB1 mRNA及蛋白表达在术后24 h显著增高（P〈0.05）.与脓毒症组比较,DT组、LDT组血浆HMGB1在术后8、24、48 h显著降低,DT组、LDT组回肠组织HMGB1 mRNA及蛋白表达在术后24 h显著降低（P〈0.05）.上述指标在LDT与DT组之间比较差异无统计学意义（P〉0.05）.结论 大承气汤治疗脓毒症的机制可能包括：①抑制肠组织HMGB1的表达,进而保护肠黏膜屏障;②降低血浆HMGB1水平,进而抑制HMGB1的某些受体（如TLR4）介导的炎症介质释放.

Objective To provide the further evidence of the mechanism of Dachengqi decoctiong treatment for sepsis through the observation of the effect of Daehengqi decoction on the high mobility group box - 1 （ HMGB1 ） in septic rats. Methods 96 SD rats were divided into four groups randomly： sham- operation group, septic group, low- dose Daehengqi decoction （LDT） group and Dachengqi decoction intervention （DT） group. The septic models were made by cecal ligation and puncture （CLP）. The LDT group and DT group were lavaged separately by low - dose Daehengqi decoction and conventional dose Dachengqi decoction, while the sham - operation group and septic group were lavaged by the equivalent normal saline at the same time. Six rats were killed randomly in each group at the point of 2, 8, 24, 48 h after CLP. Serum samples were took after centrifugation and the level of TNF- α, IL- 6 and HMGB1 were tested by ELISA. The intestinal tissue were took from the killed rats at 24 h after the CLP for the test of HMGBI mRNA level of ileum tissue by RT - PCR, the test of HMGBI protein level by immunohistochemistry and the observation of ratg pathological changes by optical microscopy. Results Compared to sham operation group, the serum and level of HMGBI in septic group increased significantly at the point of 8, 24, 48 h after CLP, and the HMGB1 mRNA and HMGB1 protein level in septic group increased significandy at the point of 24 h after CLP（ P 〈 O. 05 ）. Compared to septic group, the serum HMGB1 in DT group and LDT group decreased significantly 8, 24, 48 h after CLP, and the HMGB1 mRNA and HMGB1 protein level of ileum tissue in DT and LDT group decreased significantly at the point of 24 h after CLP（ P 〈0.05 ）. There was no difference between DT group and LDT group （ P 〉 O. 05 ）. Conclusion The study shows the mechanism of Dachengqi decoction ＇s treatment for sepsis probably includes： ① the inhibition of expression of HMGB1 in intestine. ②the decrease of serum HMGB1 expression and the inhibition of the consequent inflammatory cytokines＇ release mediated by some of HMGB1 ＇s receptors（ such as TLR4）.