CAJ | 학술논문

目的观察Ghrelin对大鼠心肌梗死后电重构的作用.方法将65只SD大鼠随机分成假手术组(n=15)和心肌梗死组(n=50).假手术组开胸后剪开心包腔,不结扎冠状动脉.心肌梗死组大鼠结扎冠状动脉前降支制作心肌梗死模型.存活7d的大鼠随机分成Ghrelin干预组(n=17)和梗死对照组(n=17).Ghrelin干预组按Ghrelin 100 μg/kg的剂量皮下注射,2次/d.梗死对照组和假手术组皮下注射等量生理盐水.28 d后采用程控刺激进行在体电生理测定,采用免疫组化方法检测缝隙连接蛋白43(Cx43)的分布,免疫印迹法检测Cx43蛋白表达,实时定量PCR法检测Cx43 mRNA表达.结果与梗死对照组相比,Ghrelin能显著降低室性心动过速(室速)的诱发率(P＜0.05),心律失常评分也显著降低(P＜0.05).与假手术组相比,梗死心肌内Cx43表达显著降低(P＜0.05),Ghrelin干预使梗死周边心肌Cx43及其mRNA水平增加(P＜0.05).结论 Ghrelin能改善心肌梗死后大鼠心脏的电生理学特性,增加心肌Cx43的表达,防止室性心律失常的发生,可能对心血管系统具有保护作用.
목적 관찰Ghrelin대대서심기경사후전중구적작용.방법 장65지SD대서수궤분성가수술조(n=15)화심기경사조(n=50).가수술조개흉후전개심포강,불결찰관상동맥.심기경사조대서결찰관상동맥전강지제작심기경사모형.존활7d적대서수궤분성Ghrelin간예조(n=17)화경사대조조(n=17).Ghrelin간예조안Ghrelin 100 μg/kg적제량피하주사,2차/d.경사대조조화가수술조피하주사등량생리염수.28 d후채용정공자격진행재체전생리측정,채용면역조화방법검측봉극련접단백43(Cx43)적분포,면역인적법검측Cx43단백표체,실시정량PCR법검측Cx43 mRNA표체.결과 여경사대조조상비,Ghrelin능현저강저실성심동과속(실속)적유발솔(P＜0.05),심률실상평분야현저강저(P＜0.05).여가수술조상비,경사심기내Cx43표체현저강저(P＜0.05),Ghrelin간예사경사주변심기Cx43급기mRNA수평증가(P＜0.05).결론 Ghrelin능개선심기경사후대서심장적전생이학특성,증가심기Cx43적표체,방지실성심률실상적발생,가능대심혈관계통구유보호작용.
Objective To observe the effects of Ghrelin on electrical remodeling in rats with myocardial infarction(MI).Methods Sixty-five adult male Sprague-Dawley rats 200 ～ 250 g(around 10 weeks old)were randomly divided into sham-operated group(n=15)and MI group(n=50).Animals in both groups were anesthetized with an intraperitoneal injection of 3％ pentobarbital sodium(30 mg/kg).The chest was opened by a left thoractomy and the heart was exposed.The left anterior descending(LAD)was ligated,and then the chest was closed.Sham group animals underwent thoracotomy and pericardiotomy,but not LAD ligation.Rats surviving for 24 h after MI were randomly assigned to receive either Ghrelin(s.c.;twice daily,at the dose of 100 μg/kg,Alexis) or saline for 4 weeks.The sham-ligated rats also received saline as a control.At 28 days after induced MI the programmed electrical stimulation was performed in vivo electrophysiological studies.The distribution of Cx43 was detected by immunohistochemical staining methods.The Cx43 expression was measured using western blot.The Cx43 mRNA expression was detected by Real-time quantitative PCR.Results Compared with the control group,Ghrelin significantly reduced the rate of induced ventricular tachycardia(P＜0.05),and the arrhythmia score was significantly lower than the control group(P＜0.05).Compared with the sham group,the expression of Cx43 within the infarcted myocardium was significantly lower(P＜0.05),Ghrelin in myocardial infarction,peripheral Cx43 and its mRNA levels increased in myocardial infarction rats received Ghrelin (P＜0.05).Conclusion Ghrelin could improve the cardiac electrophysiological properties in MI rat and increase myocardial expression of Cx43 protein,and could prevent the occurrence of ventricular arrhythmias.