右美托咪啶预处理经AMPK/SIRT1通路抑制大鼠脑缺血再灌注损伤的炎性反应

摘要

目的 探讨右美托咪啶(Dex)预处理对大鼠大脑缺血再灌注(I/R)损伤后炎性反应的作用机制.方法 72只SD大鼠随机分为6组,每组12只.①假手术组(Sham组),大鼠经腹腔注射3％戊巴比妥钠(50 mg/kg)麻醉后,只游离右侧颈内动脉,不制作成大脑中动脉闭塞(MCAO)模型;②脑缺血组(IR组):造模后,大鼠脑缺血90 min后再灌注;③Dex10组及Dex50组:造模后,缺血前30 min分别腹腔内注射10、50μg/kg Dex;④Dex50+Yoh组:造模后,在给予50 μg/kg Dex前10 min腹腔内注射育亨宾(Yoh)0.5 mg/kg;⑤Yoh组:造模后,缺血前30 min腹腔注射Yoh 0.5 mg/kg.对各组大鼠进行神经功能损伤评估、梗死面积评估、肿瘤坏死因子-α(TNF-α)及白介素-1β(IL-1β)水平测定、TUNEL染色及SIRT1蛋白检测和神经运动功能评分(TMS)检测.结果 IR组的神经功能评分、梗死面积、TUNEL(+)细胞数、TNF-a和IL-1β水平及SIRT1蛋白表达量均明显高于Sham组,再灌注后第1、2、5天时TMS评分均明显低于Sham组,差异有高度统计学意义(P＜0.01).Dex10组、Dex50组的神经功能评分、梗死面积、TUNEL(+)细胞数、脑匀浆中TNF-a和IL-1β水平均明显低于IR组、Dex50+YOH组、YOH组;TMS评分、SIRT1蛋白表达量均明显高于IR组、Dex50+YOH、YOH组,差异有高度统计学意义(P＜0.01).Dex50组神经功能评分、梗死面积、TUNEL(+)细胞数、脑匀浆中TNF-a和IL-1β水平均明显低于Dex10组;再灌注后第1、2、5天时TMS评分、SIRT1蛋白表达量明显高于Dex10组(P＜0.01).Dex50+YOH、YOH组间各项检测指标比较,差异无统计学意义(P＞0.05).结论 Dex预处理可激活α2受体通过AMPK/SIRT1通路抑制大鼠脑缺血再灌注损伤,减轻炎性反应并发挥神经保护作用.%Objective To investigate the mechanism of Dexmedetomidine (Dex) pretreatment on inflammation after cerebral ischemia/reperfusion (I/R) injury in rats.Methods Seventy-two SD rats were randomly divided into 6 groups (n=12).In sham group,after anesthesia by 3％ Pentobarbital sodium (50 mg/kg),the rates were isolated the right internal carotid artery,but they were not made into the middle cerebral artery occlusion (MCAO) model.In IR group,after the molding,the rat brain was received reperfusion at 90 min after ischemia.In Dex10 and Dex50 groups,after the molding,they were intraperitoneal injected Dex (10 μg/kg or 50μg/kg) at 30 min before ischemia.In Dex50+Yoh group,after the molding,they were intraperitoneal injected Yoh (0.5 mg/kg) before 50 μg/kg of Dex.In Yoh group,after the molding,they were intraperitoneal injected Yoh (0.5 mg/kg) before ischemia.The neurofunctional damage assessment,infarct area assessment,the levels of TNF-α and IL-1β,TUNEL staining,SIRT1 protein detection and Neuro-motor function score (TMS) in each group were detected respectively.Results In the IR group,neurofunctional scores,infarction area,TUNEL (+) cell count,levels of TNF-a and IL-1 β and SIRT1 protein expression were significantly higher than those in the sham group,while the TMS scores at 1,2 and 5 days after reperfusion were lower than those in the sham group,with highly statistically significant difference (P ＜ 0.01).The neurofunctional scores,infarction area,TUNEL (+) cell count,and TNF-a and IL-1 β levels in the Dex10 group and Dex50 group were significantly lower than those in the IR,Dex50+YOH and YOH group,while the TMS score and SIRT1 protein expression were higher than those in the IR,Dex50+YOH and YOH group,with highly statistically significant difference (P ＜ 0.01).The nerve function scores,infarction area,TUNEL (+) cell count,and TNF-a and IL-1 β levels in the Dex50 group were significantly lower than those in the Dex10 group,TMS score and SIRT1 protein expression were significantly higher than those in the Dex10 group (P ＜0.01).Therewas no statistically significant difference between the test indexes of Dex50+YOH group and YOH group (P ＞ 0.05).Conclusion Dexmedetomidine preconditioning can activate α2 adrenergic receptor through AMPK/SIRT1 pathway to inhibit cerebral ischemia reperfusion injury in rats,and reduce the inflammation.