心力衰竭家兔心肌肌浆网钙回摄功能的异常及其影响因素  

Abnormal calcium re-uptake in myocardium sarcoplasmic reticulum in rabbits with heart failure and the influencing factors

作　　者：王蕾[1] 张世杰[2] 李莉[1] 兰超[1] 张瑞[1] 刘志华[3] 

机构地区：[1]郑州大学第一附属医院急诊科,郑州450052 [2]郑州大学第一附属医院检验科,郑州450052 [3]苏州大学附属第一医院心内科,苏州215006

出　　处：《生理学报》2014年第4期483-488,共6页Acta Physiologica Sinica

基　　金：supported by Youth Science Foundation Item of the National Natural Science Foundation of China(No.30800460)

摘　　要：本文旨在探讨心力衰竭家兔心肌肌浆网钙回摄功能的异常及其影响因素和可能的机制。用主动脉破瓣术加腹主动脉缩窄术造心衰模型,用钙离子荧光成像仪检测心肌肌浆网钙回摄功能,用无机磷酸根法测定心肌肌浆网钙泵的活性,用Western blot检测各组心肌组织中肌浆网钙泵(SERCA2a)、受磷蛋白(PLB)、16位丝氨酸磷酸化-受磷蛋白(PLB-Ser16)、17位苏氨酸磷酸化-受磷蛋白(PLB-Thr17)、Ca2+∕钙调素依赖的蛋白激酶II(CaMKII)、蛋白激酶A(PKA)和蛋白磷脂酶(PP1α)的蛋白表达,用γ-32P底物掺入法测定CaMKII、PKA的活性。结果显示,与假手术组相比,心衰组钙回摄量显著下降(P<0.01),SERCA2a在心肌中的表达量和活性均显著下降(P<0.05),PLB的表达水平及其磷酸化位点(Ser16、Thr17)的磷酸化状态明显降低(P<0.05),且PKA和CaMKII的表达及活性均明显升高(P<0.05或P<0.01),PP1α的表达量显著升高(P<0.05)。以上结果证实心衰家兔模型心肌肌浆网钙回摄功能的异常与SERCA2a的表达活性、PLB及其磷酸化水平均显著下降有关,提示PLB的两个磷酸化位点(Ser16、Thr17)可能共同参与心衰家兔心肌肌浆网钙泵活性的调节。The aim of the present study was to investigate the abnormal calcium re-uptake function of myocardium sarcoplasmic retic- ulum （SR） in rabbits with heart failure, as well as potential mechanisms. Heart failure model was established in rabbits through aortic insufficiency and constriction of abdominal aorta. The SR Ca2＋ re-uptake function was measured with a calcium imaging device. The activity of myocardium SR calcium adenodine triphosphatase 2a （SERCA2a） was measured by inorganic phosphate. The protein expressions of SERCA2a, CaMKII, PKA, PPlct, phospholamban （PLB）, PLB-Ser16 and PLB-Thr17 were evaluated by Western blot. The activities of PKA and CaMKII were detected by 7-32P substrate incorporation. The results showed that, compared with the sham operation group, the heart failure group exhibited reduced Ca2＋ re-uptake amount （P 〈 0.01） and the expression and activity of SER- CA2a （P 〈 0.05 or P 〈 0.01）, decreased expression of PLB and its phosphorylation status in sites of Ser16 and Thr17 （P 〈 0.05）, increased expressions and activities of PKA and CaMKII （P 〈 0.05 or P 〈 0.01）, and increased expression of PPlct （P 〈 0.05）. These results suggest that the abnormal Ca2＋ re-uptake function in heart failure is related with reduced expression and activities of SERCA2a, as well as reduced expression of PLB and its phosphorylation status. Both PLB-Ser16 and -Thr17 may be involved in the regulation of myocardium SR calcium pump activity in heart failure.

关 键 词：心力衰竭 钙回摄 肌浆网 受磷蛋白 

分 类 号：R541.6[医药卫生—心血管疾病]