脑心相互作用对心肌缺血再灌注损伤的影响

Influence of brain-heart interaction on myocardial ischemia reperfusion injury

目的探究下丘脑腹内侧核团腹外侧亚区(VMHvl)在脑心轴中的作用及其对心肌缺血再灌注损伤的影响。方法将18只大鼠随机分为假手术组(Sham组,n=6,心肌缺血假手术),心肌缺血再灌注组(I/R组,n=6,心肌I/R)和化学遗传组(Pharm组,n=6,化学遗传+心肌I/R)。利用化学遗传学技术激活Pharm组大鼠VMHvl,持续30 d。测量心脏缺血再灌注造模前的大鼠血压,检测再灌注后心肌组织病理结构变化,测定再灌注24 h后的左心室各部位有效不应期(ERP)。结果慢性激活VMHvl可升高大鼠血压,Pharm组大鼠的收缩压、舒张压及平均动脉压均显著高于Sham和I/R组(P<0.05),而Sham组与I/R组之间血压并无显著差异(P>0.05);HE染色结果显示Pharm组心肌缺血再灌注后心肌细胞坏死程度和炎症细胞浸润水平高于I/R组;I/R组左心室各部位ERP显著低于Sham组(P<0.05),而与I/R组比较,Pharm组ERP进一步降低(P<0.05)。结论VMHvl激活可加重心肌缺血再灌注损伤。

Objective To study the effect of ventrolateral subdivision of ventromedial hypothalamus(VMHvl)in brain-heart axis and its influence on myocardial ischemia reperfusion injury(MIRI).Methods all rats(n=18)were randomly divided into Sham group(received sham surgery),myocardial ischemia reperfusion group(I/R group,received myocardial I/R),and Pharm group(received pharmacogenetic activation and myocardial I/R,each n=6).VMHvl was activated by using chemogenetics technology in Pharm group for continuous 30 d.The blood pressure(BP)was measured before I/R modeling,changes of myocardial pathological structure were detected after MIRI,and effective refractory period(ERP)of each left ventricular parts were detected after MIRI for 24h.Results The chronic activation of VMHvl raised BP in rats.In Pharm group,systolic blood pressure(SBP),diastolic blood pressure(DBP)and mean arterial pressure(MAP)were significantly higher than those in Sham group and I/R group(P<0.05),and there was no significant difference between Sham group and I/R group(P>0.05).The results of HE staining showed that degree of cardiomyocyte necrosis and level of inflammatory cell infiltration were higher in Pharm group than those in I/R group.ERP was significantly lower in I/R group than that in Sham group(P<0.05),and ERP decreased further in Pharm group compared with I/R group(P<0.05).Conclusion The activation of VMHvl can aggravate MIRI.