中枢吗啡后处理对在体大鼠缺血后心肌的保护作用

目的探讨中枢吗啡后处理对在体大鼠缺血后心肌是否产生保护作用及其机制。方法42只♂SD大鼠,建立侧脑室置管和心肌缺血/再灌注损伤模型,随机分为7组:假手术组(Sham)、对照组(CON)、静脉对照组(VCON)、后处理组(POC)和吗啡后处理组(MOC),MOC组根据吗啡不同给药剂量(3、0.3、0.03μg.kg-1)分为MOC1组、MOC2组、MOC3组。观察指标有:平均动脉压(MAP)、心率(HR)、压力心率乘积(RPP)、缺血危险区(AAR)、梗死区(IS)体积、IS/AAR以及再灌注120min时血浆肌钙蛋白I(cTnI)含量。取CON组、MOC2组、POC组和Sham组大鼠的脑组织,观察各组孤束核中c-fos蛋白的表达。结果与CON组相比,POC组、MOC组IS/AAR和cTnI明显降低(P<0.05,P<0.01)。VCON组与CON组无明显差异(P>0.05)。POC组、MOC2组中c-fos蛋白在孤束核中表达明显减少(P<0.01)。结论中枢吗啡后处理对在体大鼠缺血后心肌产生了保护作用,这种保护作用可能和中枢中c-fos蛋白表达的下调有关。

Cardioprotective effects of intracerebroventricular morphine postconditioning against ischemia-reperfusion injury in rat heart

Aim To investigate the effect of intracerebroventricular morphine postconditioning against ischemia-reperfusion injury in rat heart and the mechanism of the central nervous system opioid receptor.Methods Forty-two Sprague-Dawley Rats were established intracerebroventricular catheter placement and myocardial ischemia/reperfusion models and randomly assigned to 7 groups:Sham group(Sham),control group(CON),intravenous control group(VCON),morphine postconditioning group(POC),intracereborventricular morphine postconditioning group(MOC).According to the dosage of intracerebroventricular morphine(3 μg·kg-1,0.3 μg·kg-1,0.03 μg·kg-1),MOC group was assigned to three groups :MOC 1,MOC 2,MOC 3.Infarct size(IS),a percentage of the area at risk(AAR) was determined by triphenyltetrazolium(TTC) staining.c-fos expression in nucleus of tractus solitarius was determined by immunohistochemical method and Cardiac TroponinI(cTnI) of serum was observed at 120 min of reperfusion.Results Compared with control group,IS,IS/AAR and cTnI were significantly reduced in POC and MOC groups(P<0.05,P<0.01).CON and VCON have no difference(P>0.05).c-fos expression in nucleus of tractus solitarius were significantly reduced in MOC 2,POC(P<0.01).Conclusion intracerebroventricular morphine postconditioning against ischemia-reperfusion injury in rat heart and the cardioprotective effect may mediated cfos.