摘要
目的观察异丙酚对大鼠在体心肌缺血/再灌注时核因子-κB(NF-κB)信号途径的影响,以探讨异丙酚的心肌保护作用机制。方法阻断大鼠左冠状动脉前降支30min,再灌注2h引起心肌缺血/再灌注损伤。60只SD大鼠随机分为假手术组(Sham)、缺血/再灌注组(I/R)和异丙酚3、6、12mg·kg-1·h-1组。分别于缺血前、缺血30min末、再灌注2h末记录心率、平均动脉压,并计算心率-血压指数。ELISA及放射免疫法分别测定血清、心肌中肿瘤坏死因子α(TNF-α)、白介素1β(IL-1β)的含量。分别用原位杂交法(ISH)和半定量RT-PCR法检测心肌组织中诱导型一氧化氮合酶(iNOS)、粘附分子1(ICAM-1)的mRNA的表达。免疫组化染色分析心肌组织中NF-κB的核移位,Western blot检测心肌组织NF-κB的表达量。结果缺血/再灌注后各组大鼠的平均动脉压、血压-心率指数均呈进行性下降(与Sham组相比P<0.05)。异丙酚12mg·kg-1·h-1组在缺血/再灌注后的平均动脉压和血压-心率指数明显高于I/R组(P<0.05)。与Sham组相比,I/R组NF-κB活化,明显从细胞质移位于细胞核,表达量也增加(P<0.05);血清、心肌中TNF-α、IL-1β含量明显升高(P<0.01),心肌中iNOSmR-NA、ICAM-1 mRNA表达增强(P<0.01)。而异丙酚6、12mg·kg-1·h-1组,NF-κB从细胞质向细胞核的移位被明显限制,NF-κB的表达量也明显低于I/R组(均P<0.05);血清、心肌中TNF-α、IL-1β含量明显较I/R组降低(P<0.05),心肌中iNOS mRNA、ICAM-1 mRNA表达减弱(与I/R组相比,P<0.05,P<0.01)。结论异丙酚能减轻缺血/再灌注损伤,同时明显抑制心肌缺血/再灌注时NF-κB的活化,阻断NF-κB相关信号通路的传导,下调TNF-α、IL-1β、ICAM-1和iNOS等炎症相关因子的表达。
Aim To explore the molecular mechanisms of propofol in cardioprotection,the activation of NF-κB and NF-κB-regulated inflammatory mediator expression was examined with the model of ischemia/reperfusion in rat heart.Methods Rat myocardium I/R injury was induced by occlusion of the left main coronary artery for 30 min and reperfusion for 2 h.Propofol（3,6,12 mg·kg-1·h-1）was intravenously given at 15 min before ischemia.Heart rate（HR）,mean arterial blood pressure（MAP） and pressure-rate index（PRI）were recorded under basal conditions,during the occlusion and at the end of reperfusion,respectively.The translocation of NF-κB in the cardiomyocytes was detected by immunohistochemistry,and NF-κB expression was determined by Western blot.The concentrations of TNF-α,IL-1β in serum and myocardium were evaluated by ELISA and radioimmunoassay,respectively.The cardiac amount of mRNA codifying for intercellular adhesion molecule-1（ICAM-1）and inducible nitric oxide synthase（iNOS） was investigated by RT-PCR and in situ hybridization（ISH）,respectively.Results At the end of reperfusion,the cardiac function parameters（HR,MAP,pressure-rate index） in I/R group were lower than those of sham group（P0.05）.Compared with those of I/R group,administration of 12 mg·kg-1·h-1 propofol resulted in improvement in MAP and PRI（P0.05）.Compared with the sham group,NF-κB significantly translocated from the cytoplasm into the nucleus in the I/R group.And the expression of NF-κB in the nuclei was markedly higher than that in the sham group（P0.05）.In addition,the concentrations of TNF-α,IL-1β in serum and myocardium,and the expression of ICAM-1 mRNA,iNOS mRNA in myocardium significantly increased in the I/R group（P0.05）.Compared with those of I/R group,administration of propofol at 6,12 mg·kg-1·h-1 significantly inhibited the NF-κB translocation into nucleus and attenuated the expression of NF-κB in the nuclei（P0.05）,decreased the concentrations of TNF-α,IL-1β in serum and myocardium（P0.05）and the expression of ICAM-1 mRNA and iNOS mRNA in myocardium（P0.05）,respectively.Conclusion Propofol reduces the inflammatory response in myocardium ischemia reperfusion injury,inhibits NF-κB activation,and subsequently leads to down-regulation of NF-κB-dependent inflammatory gene expression,which may be the molecular mechanism of its cardioprotection.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2009年第11期1491-1496,共6页
Chinese Pharmacological Bulletin
基金
河北省卫生厅医学研究重点项目(No05036)
