心肌肥厚大鼠心肌肌浆网和核被膜ryanodine受体变化的研究  

Alterations in ryanodine receptors in cardiac sarcoplasmic reticulum and nuclear envelope isolated from cardiac hypertrophic rats

作　　者：王培勇[1] 杨军 董林旺 庞永政 苏静怡 唐朝枢 刘乃奎 

机构地区：[1]重庆第三军医大学高原医学研究室病理生理教研室,重庆400038 [2]北京医科大学第一临床医学院心血管病研究所,北京100083

出　　处：《中国危重病急救医学》2001年第10期582-586,共5页Chinese Critical Care Medicine

基　　金：国家自然科学基金资助项目 ( No.3 970 0 2 0 0;No.3 9870 3 47和 No.3 9870 3 92 )

摘　　要：目的 :观察心肌肥厚大鼠心肌肌浆网 ( sarcoplasmic reticulum,SR)和核被膜 ( nuclear envelope,NE)的 ryanodine受体 ( Ry R)的变化 ,进一步探讨心肌肥厚发生机制。方法 :采用腹主动脉缩窄术制作心肌肥厚模型。用差速离心和密度梯度离心法分离心肌 SR和 NE,用同位素标记配体研究 Ry R的动力学特征。结果 :心肌细胞 NE上也存在 Ry R,其最大结合 ( Bmax)为 SR的 1 / 68,而离解常数 ( Kd)为 SR的 61 %。与假手术组相比 ,术后 4周大鼠心肌显著肥厚 ,左室重量指数增加 4 4 % ,左心功能代偿性增加 ,心肌 SR的 Ry R最大结合增加2 0 % ,而 NE的该受体 Bmax则增加 1倍 ,SR与 NE的 Bmax比值显著降低 ( P<0 .0 1 ) ;Kd与对照组接近。结论 :大鼠心肌细胞 NE上存在低密度、高亲和 Ry R,心肌肥厚时心肌 SR和 NE的 Ry R均上调 ,而 NE的受体增加幅度更大 ,这些改变可能参与心肌肥厚时心功能代偿和核反应异常的发生。Objective:To observe changes in ryanodine receptors (RyRs) in cardiac sarcoplasmic reticulum (SR) and nuclear envelope (NE) isolated from cardiac hypertrophic rats,and to explore the mechanism underlying cardiac hypertrophy.Methods:Cardiac hypertrophy was induced by abdominal aortic coarctation.Myocardial SR and NE were fractionated with velocity and isopycnic gradient centrifugation.RyRs were assayed with 3 H labeled ligand.Results:RyRs with maximal binding ( B max) and dissociating ratio ( Kd ) of 1/68 and 61% respectively also existed in myocardial NE.Four weeks after operation,significant cardiac hypertrophy developed with a compensated left ventricular function.The B max of RyRs in SR and NE increased by 20% and 100% respectively in hypertrophic myocardium compared with controls ( P <0 01).The Kd for 〔 3H〕 ryanodine binding to SR and NE was unchanged.Conclusions:There are RyRs in myocardial NE,with lower density and higher affinity than those in SR.Upregulation of RyRs in both SR and NE,and especially in NE,might be involved in the development of mycardial hypertrophy.

关 键 词：心肌肥厚 RYANODINE受体 核被膜 肌浆网 

分 类 号：R363[医药卫生—病理学]