CAJ | 학술논문

目的:研究β肾上腺素激活的PKA信号通路与成年大鼠心肌细胞RyR2介导的肌浆网Ca~(2+)泄漏之间的关系,探讨治疗心力衰竭的新方法.方法:NiCl_2(5 mmol/L)和毒胡萝卜素(TG,100 nmol/L)分别阻断成年大鼠心室肌细胞的钠钙交换体和钙泵,胞外灌流异丙肾上腺素(ISO,1μmol/L).采用激光扫描共聚焦显微镜记录灌流前后细胞内钙火花及[Ca~(2+)]_i的变化,并使用Ca~(2+)通道阻断剂钌红(RR,5 μmaol/L)对β肾上腺素刺激作用进行逆转,进而阻断RyR2介导的肌浆网内钙泄漏.结果:ISO胞外灌流后,心肌细胞钙火花发生率和[Ca~(2+)]_i与对照组相比明显升高(n=10,P<0.05);加入RR后,心肌细胞内钙火花发生率与对照组比较显著降低(n=20,P<0.05),[Ca~(2+)]_i两组没有明显差别(n=20,P>0.05).结论:ISO激活PKA信号通路后可诱导心肌细胞RyR2介导的钙泄漏,RR可有效地逆转这种钙泄漏.
목적:연구β신상선소격활적PKA신호통로여성년대서심기세포RyR2개도적기장망Ca~(2+)설루지간적관계,탐토치료심력쇠갈적신방법.방법:NiCl_2(5 mmol/L)화독호라복소(TG,100 nmol/L)분별조단성년대서심실기세포적납개교환체화개빙,포외관류이병신상선소(ISO,1μmol/L).채용격광소묘공취초현미경기록관류전후세포내개화화급[Ca~(2+)]_i적변화,병사용Ca~(2+)통도조단제조홍(RR,5 μmaol/L)대β신상선소자격작용진행역전,진이조단RyR2개도적기장망내개설루.결과:ISO포외관류후,심기세포개화화발생솔화[Ca~(2+)]_i여대조조상비명현승고(n=10,P<0.05);가입RR후,심기세포내개화화발생솔여대조조비교현저강저(n=20,P<0.05),[Ca~(2+)]_i량조몰유명현차별(n=20,P>0.05).결론:ISO격활PKA신호통로후가유도심기세포RyR2개도적개설루,RR가유효지역전저충개설루.
Objective:To study the relationship between PKA signaling pathway activated by the β-adrenergic and the ryanodine receptor Ⅱ (RyR2) mediated calcium leak in the cardiac myocytes of adult rat and explore the new way of treating heart failure . Methods: Using the NiCl_2 (5 mmol/L) and thapsigargin (TG, 100nmol/L) respectively to block the sodium-calcium exchanger (NCX) and SR Ca-ATPase (SERCA2) , and then perfusing Isoproterenol (ISO, 1 μmol/L) within the extracellular solution to activate the PKA signaling pathway in the cardiac myocytes. Finally we employ the the sarcoplasmic reticulum (SR) Ca~(2+) release inhibitor, ruthenium red (RR,5 μmol/L) to rev2erse the function of the ISO. The calcium sparks and [Ca~(2+)]_i changes were recorded by the laser scanning confocal microscope imaging system. Results:The incidence of calcium sparks and the [Ca~(2+)]_i after perfusing ISO ignificantly increased compared with that under the control conditions (n = 10, P < 0.05); After perfusing RR, the incidence of calcium sparks significantly decreased compared with that of the condition without perfusing RR, (n = 20, P < 0.05), while the [Ca~(2+)]_i stopped increasing after perfusing RR and the line of[Ca~(2+)]_i gradually became smooth . Conclusion : PKA signaling pathway activated by ISO could induce the calcium leak through RYR2 located on the SR of myocardial cell, and RR could effectively reverse such calcium leak.