间歇性低压氧通过δ-阿片类受体表达保护心肌梗死大鼠心肌的研究

Study on intermittent hypobaric hypoxia protection of myocardial infarction rats byδ-opioid receptor ex⁃pression

目的:研究间歇性低压氧(intermittent hypobaric hypoxia,IHH)能否提高δ-阿片类受体(delta-opioid receptor,DOR)的表达,对大鼠心肌梗死(myocardial infarction,MI)后心肌产生保护作用。方法:24只SD大鼠随机分为假手术常氧干预组(Sham-Nor)、假手术低压氧干预组(Sham-IHH)、心梗常氧干预组(MINor)和心梗低压氧干预组(MI-IHH)。心肌梗死造模1周后进行干预。4周后检测心脏重量指数、心肌纤维化程度、超声检测心脏功能及DOR蛋白表达。结果:4周后,MI-IHH和MI-Nor组相比:心脏重量无显著性差异(P>0.05),MI-IHH组心肌纤维化显著减少(P<0.05)、左室收缩末内径(left ventricular end systolic diameter,LVESd)明显下降(P<0.01)、左室射血分数(left ventricular ejection fraction,LVEF)显著提高(P<0.001)、DOR显著增加(P<0.05),MI-Nor和MI-IHH组中DOR表达与LVEF呈正相关(P<0.05)。结论:IHH能够通过提高大鼠DOR的表达产生心肌梗死后心肌保护作用。

Objective:To find out whether intermittent hypobaric hypoxia can increase the expression of delta-opioid receptor(DOR)and protect myocardium after myocardial infarction in rats.Method:Twenty-four rats were randomly divided into four groups:Sham-Nor group,Sham-IHH group,MINor group and MI-IHH group.One week after left anterior descending coronary artery ligation,rats were exposed to different treatments.After 4 weeks’treatment,the heart weight ratio,myocardial fibrosis area,cardiac function detected by echocardiography and delta-opioid receptor(DOR)expression were measured.Result:Four weeks later,there was no difference in heart weight ratio between MI-Nor group and MI-IHH group(P>0.05).Compared with MI-Nor group,myocardial fibrosis area decreased(P<0.05),left ventricular end systolic diameter(LVESd)decreased(P<0.01),left ventricular ejection fraction(LVEF)increased(P<0.001)and DOR expression elevated(P<0.05)in MI-IHH group.DOR expressions were positive relate to LVEF in MINor group and MI-IHH group(P<0.05).Conclusion:IHH can protect myocardium after myocardial infarction by increasing DOR expression in rats.