Zou Cao, Liu Zhi-hua, Jiang Bin, Miao Li-yan, Qian Mei-ying, Zhang Hua, Song Jian-ping, Yang Xiang-jun, Jiang Ting-bo, Jiang Wen-ping
Department of Cardiology, First Affiliated Hospital of Suzhou University, Suzhou 215006, China.
Zhonghua Xin Xue Guan Bing Za Zhi. 2006 Sep;34(9):789-92.
To investigate the abnormal abundances of calcium regulatory proteins in rabbit myocytes with failing hearts.
Sixteen rabbits were divided into two groups: 8 rabbits with heart failure induced by volume plus pressure overload and 8 sham-operated animals. The hemodynamic parameters and cardiac structure and function were detected via catheterization and echocardiography respectively. L-type calcium channel (LTCC), Ryanodine receptor 2 (RyR2), Sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a), and Na(+)-Ca(2+) exchanger (NCX) protein abundances were determined by Western blot analysis.
The ratio of left ventricular mass to body weight, heart rate and left ventricular end diastolic pressure in heart failure rabbits were significantly increased compared with sham-operated rabbits (P < 0.01), but their left ventricular shorten fraction [(21.3 +/- 4.00)% vs. (36.5 +/- 1.36)%] and ejection fraction (0.45 +/- 0.07 vs. 0.70 +/- 0.02) were decreased (P < 0.01). In heart failure rabbits, the abundances of LTCC and RyR2 were significantly decreased (R(LTCC/actin): 0.287 +/- 0.029 vs. 0.624 +/- 0.009; R(RyR2/actin): 0.106 +/- 0.001 vs. 0.203 +/- 0.011; P < 0.01), whereas the expressions of SERCA2a and NCX were markedly increased (R(NCX/actin): 0.497 +/- 0.015 vs. 0.221 +/- 0.014; R(SERCA2a/actin): 0.611 +/- 0.036 vs. 0.433 +/- 0.008; P < 0.01).
Reductions of LTCC and RyR2 might contribute to risk factors of systolic dysfunction in failing hearts. In early stage of heart failure, upregulated SERCA2a and NCX protein levels may be helpful for maintaining cardiac performance.
研究衰竭心脏兔心肌细胞中钙调节蛋白的异常丰度。
将16只兔子分为两组：8只通过容量加压力超负荷诱导心力衰竭的兔子和8只假手术动物。分别通过导管插入术和超声心动图检测血流动力学参数以及心脏结构和功能。通过蛋白质免疫印迹分析测定L型钙通道（LTCC）、兰尼碱受体2（RyR2）、肌浆网Ca(2+)-ATP酶（SERCA2a）和钠钙交换体（NCX）蛋白的丰度。
与假手术兔子相比，心力衰竭兔子的左心室质量与体重之比、心率和左心室舒张末期压力显著增加（P < 0.01），但其左心室缩短分数[（21.3±4.00）%对（36.5±1.36）%]和射血分数（0.45±0.07对0.70±0.02）降低（P < 0.01）。在心力衰竭兔子中，LTCC和RyR2的丰度显著降低（R(LTCC/肌动蛋白)：0.287±0.029对0.624±0.009；R(RyR2/肌动蛋白)：0.10±0.001对0.203±0.011；P < 0.01），而SERCA2a和NCX的表达明显增加（R(NCX/肌动蛋白)：0.497±0.015对0.221±0.014；R(SERCA2a/肌动蛋白)：0.611±0.036对0.433±0.008；P < 0.01）。
LTCC和RyR2的减少可能是衰竭心脏收缩功能障碍危险因素的原因。在心力衰竭早期，SERCA2a和NCX蛋白水平上调可能有助于维持心脏功能。
