吴茱萸次碱通过抑制TLR4/NF-κB信号通路保护大鼠心肌缺血/再灌注损伤

Rutaecarpine protects against myocardial ischemia/reperfusion injury through inhibiting Toll-like receptor 4/NF-κB signaling pathway in rats

目的研究吴茱萸次碱是否通过抑制Toll样受体4(TLR4)/NF-κB信号通路保护大鼠心肌缺血/再灌注(I/R)损伤,以及其作用是否与促进降钙素基因相关肽(CGRP)释放有关。方法 SD大鼠在I/R前10 min静脉注射吴茱萸次碱和capsazepine(给吴茱萸次碱前2 min静脉注射),然后结扎左冠状动脉前降支缺血60 min,再灌注3 h。测定心肌梗死面积、血浆中CGRP浓度和血清中肌酸激酶的活性;RTPCR分析心肌组织TLR4 mRNA表达水平;免疫组织化学方法检测心肌组织TLR4和NF-κB蛋白表达水平。结果吴茱萸次碱(100、300μg·kg^(-1))能明显降低心肌梗死面积和血清肌酸激酶活性,增加血浆CGRP浓度(P<0.05)。与I/R组比较,预先给予吴茱萸次碱也能明显降低TLR4 mRNA和蛋白表达以及NF-κB蛋白表达(P<0.05)。这些作用可被预先给予选择性辣椒素受体拮抗剂capsazepine(1.5 mg·kg^(-1))所取消。结论吴茱萸次碱通过抑制TLR4/NF-κB信号通路保护心肌I/R损伤,此作用与促进CGRP释放有关。

AimTo investigate whether the protection of rutaecarpine against myocardial ischemia/reperfusion(I/R)injury is mediated by Toll like receptor4(TLR4)/NFκB pathway,and whether these effects are related to the release of calcitonin gene related peptide(CGRP)in plasma.MethodsSprague Dawley rats were subjected to60min of ligation of the left anterior descending coronary followed by3h of reperfusion to induce I/R injury.Rats were pretreated with rutaecarpine10min before the ligation,and some rats were pretreated with capsazepine2min before rutaecarpine administration.Myocardial infarct size,CGRP concentration in plasma and creatine kinase(CK)activity in serum were measured.The expression of TLR4mRNA in myocardial tissue was determined by RT PCR.The protein expression of TLR4and NFκB in myocardial tissue was analyzed by immunohistochemistry.ResultsRutaecarpine(100,300μg·kg-1,iv)significantly reduced the infarct size and the serum CK activity concomitantly with the increase in plasma CGRP concentration(P<005).Importantly,the expression of TLR4(both mRNA and protein)and NFκB(protein)was increased by myocardial I/R injury,and dramatically inhibited by rutaecarpine pretreatment(P<005).All these effects of rutaecarpine were abolished by capsazepine(15mg·kg-1,iv),a specific antagonist for vanilloid receptor1.ConclusionRutaecarpine protects against myocardial I/R injury by inhibiting TLR4/NFκB pathway,which is related to the increased release of CGRP.