摘要
目的探讨牛磺酸(taurine,Tau)对心肌缺血-再灌注损伤时血浆心肌肌钙蛋白T(cardiac troponin T,cT-nT)及心肌葡萄糖调节蛋白78(glucose-regulated protein 78,GRP78)、胱天蛋白酶(Caspases)-12表达的影响及其意义。方法将50只大鼠按随机数字表法分为5组:假手术组(对照组,Sham组)、缺血-再灌注组(I/R组)和Tau保护1组(Tau 1组)、Tau保护2组(Tau 2组)、Tau保护3组(Tau 3组),每组10只。采用结扎大鼠冠状动脉左前降支1h,随后再灌注24h以建立心肌缺血-再灌注损伤动物模型;Tau 1组、Tau 2组、Tau 3组分别在结扎冠状动脉前1h腹腔注射Tau 100、200、300mg·kg-1,余操作同I/R组;Sham组大鼠冠状动脉左前降支仅穿线,不结扎。采用酶联免疫法测定血浆cTnT水平,TUNEL法检测心肌细胞凋亡,RT-PCR法和免疫组织化学法分析心肌细胞GRP78、Caspase-12基因表达,荧光分析法测定Caspase-3活性。结果与Sham组比较,I/R组大鼠血浆cTnT、心肌组织中GRP78、Caspase-12mRNA和蛋白表达、细胞凋亡指数及Caspase-3活性均显著升高(均P<0.01);与I/R组比较,Tau 1组、Tau 2组、Tau 3组大鼠血浆cTnT水平、心肌组织中GRP78mRNA、Caspase-12mRNA和蛋白表达、细胞凋亡指数及Caspase-3活性均呈显著降低(均P<0.05)。结论 Tau可显著减轻心肌缺血-再灌注损伤,其作用机制可能是Tau能下调缺血-再灌注心肌中GRP78和Caspase-12过表达。
Objective To explore the effects of taurine（Tau） on plasma cardiac troponin T（cTnT） levels and myocardial glucose-regulated protein 78（GRP78） and caspase-12 expression in rats undergoing ischemia-reperfusion（I/R）.Methods Fifty rats were randomly divided into five groups：sham operation group（sham group）,I/R group,I/R＋Tau 100 mg·kg-1（Tau 1 group）,I/R＋Tau 200 mg·kg-1（Tau 2 group）,I/R＋Tau 300 mg·kg-1（Tau 3 group）,with 10 rats in each group.Myocardial I/R injury was induced by left anterior descending artery（LAD） ligation for 1 hour and reperfusion for 24 hours.Tau was intraperitoneally injected 1 hour before LAD ligation.Rats in sham group underwent placement of suture without ligation.Plasma cTnT levels were measured by ELISA.Cardiomyocyte apoptosis was detected by TUNEL assay.The expression of GRP78 and caspase-12 was determined by RT-PCR and immunohistochemistry.Caspase-3 activity was examined by fluorospectrophotometry.Results Compared with sham group,plasma cTnT levels,myocardial mRNA and protein expression of GRP78 and caspase-12,apoptosis index,and caspase-3 activity significantly increased in I/R group（all P0.01）.Compared with I/R group,cTnT levels,GRP78 and caspase-12 expression,apoptosis index,and caspase-3 activity obviously decreased in Tau 1,Tau 2 and Tau 3 groups（all P0.05）.Conclusion Tau can attenuate myocardial I/R injury through down-regulating the expression of myocardial GRP78 and caspase-12.
出处
《南昌大学学报（医学版）》
CAS
2013年第3期5-10,共6页
Journal of Nanchang University：Medical Sciences
基金
江西省自然科学基金(2010JZY0237)
江西省科技支撑计划项目(2009JX01081)
江西省教育厅资助项目(GJJ10317)
