后肢远程预处理对心肌缺血再灌注与心交感神经损伤的影响

Effects of lower extremities remote preconditioning on cardiac muscle ischemic reperfusion and sympathetic nervous injury

目的:后肢远程缺血预处理对急性心肌缺血再灌注与心交感神经损伤影响的实验研究。方法:20只雄性新西兰大白兔随机被均分成两组:对照组及远程缺血预处理(RIPC)组。两组均制作心肌缺血模型。RIPC组在心肌缺血前行双后肢短暂缺血预处理2次(充气式压力止血带环扎双后肢腘窝上1/3,压力26.6 kPa,每次10 min,间隔10 min),最后一次后肢缺血预处理后再灌注60 min制作急性心肌缺血模型。其方法为:冠状动脉左前降支完全闭塞45 min,于松开结扎圈再灌注2、4 h时,分别以131碘-间位碘代苄胍(131I-MIBG)、99m锝-甲氧基异丁基异腈(99mTc-MIBI)双核素作放射自显影,其后以美蓝、氯化四唑(TTC)作组织染色,分别确定心肌危险梗塞灶与实际梗塞灶。结果:再灌注4h后,预处理组危险梗塞灶与实际梗塞灶均小于对照组(P<0.01)。131I-MIBG及99mTc-MIBI自显影在同一区域摄取存在差异性,两组131I-MIBG显影缺损面积(40.8±3.2)%,均显著比99mTc-MIBI显影缺损及实际梗塞灶大(P<0.05)。结论:远程预处理能有效阻断心肌缺血再灌注对交感神经损伤的作用;利用交感神经显影剂MIBG显影能客观监测心肌梗塞病变范围和程度,评价远程预处理的心肌保护效应。

Objective： To study the effects of lower extremities remote preconditioning on cardiac muscle ischemic reperfusion and sympathetic nervous injury. Methods： Twenty male New Zealand white rabbits were randomly average divided into two groups： control group （group C） and remote ischemic preconditioning group （group RIPC）. Mode of cardiac muscle ischemic all made in two groups. Before left anterior descending coronary artery were occluded, a hind - limb ischemia preconditioning 2 times with obstructed by inflated blood pressure cuff keep on 200 mmHg for 10min with 10min interval, then followed by 60min reperfusion. Autoradiography with ^131I-Metaiodobenzyguanidine （^131I-MIBG） and ^99mTc-sestamibi （^99mTc--MIBI） were respectively performed in all rabbits of which left anterior descend- ing coronary artery was completely occluded for 45min and followed by 2h, 4h reperfusion. The area at risk and the in- farct size were determined by staining with methylene blue and triphenyl tetrazolium chloride （TTC） respectively. Results： After 4h reperfusion, compared with group RIPC, whether risk or infarct areas, ^131I--MIBG and ^99mTc--MIBI defects increased （P〈0.01） in control group, ^131 I--MIBG autoradiaography imaging defected area of two groups was larger than that of ^99mTc--MIBI imaging defected and infarct area size. Conclusion： Remote ischemic preconditioning pretreatment significantly reduces myocardial infarction area induced from ischemia reperfusion injury in rabbits. MIBG can monitor the infarct areas and extent, it have favourable objectivity to evaluate myocardial preservation effect by RIPC.