Department of Mechanical Science and Engineering, University of Illinois at Urbana Champaign-Illinois, 142 MEB MC: 244, 1206 W. Green Street, Urbana, Illinois 61801, USA.
Biotechnol Bioeng. 2013 Feb;110(2):628-36. doi: 10.1002/bit.24725. Epub 2012 Oct 23.
Cardiac myocytes originating from different parts of the heart exhibit varying morphology and ultrastructure. However, the difference in their dynamic behavior is unclear. We examined the contraction of cardiac myocytes originating from the apex, ventricle, and atrium, and found that their dynamic behavior, such as amplitude and frequency of contraction, differs depending on the heart segment of origin. Using video microscopy and high-precision image correlation, we found that: (1) apex myocytes exhibited the highest contraction rate (∼17 beats/min); (2) ventricular myocytes exhibited the highest contraction amplitude (∼5.2 micron); and (3) as myocyte contraction synchronized, their frequency did not change significantly, but the amplitude of contraction increased in apex and ventricular myocytes. In addition, as myocyte cultures mature they formed contractile filaments, further emphasizing the difference in myocyte dynamics is persistent. These results suggest that the dynamic behavior (in addition to static properties) of myocytes is dependent on their segment of origin.
源自心脏不同部位的心肌细胞表现出不同的形态和超微结构。然而，其动态行为的差异尚不清楚。我们检查了源自心尖、心室和心房的心肌细胞的收缩情况，发现它们的动态行为，如收缩的幅度和频率，取决于起源的心脏节段。使用视频显微镜和高精度图像相关，我们发现：（1）心尖细胞表现出最高的收缩率（约 17 次/分钟）；（2）心室细胞表现出最高的收缩幅度（约 5.2 微米）；（3）随着心肌细胞收缩同步，其频率没有明显变化，但心尖和心室细胞的收缩幅度增加。此外，随着心肌细胞培养的成熟，它们形成了收缩丝，进一步强调了心肌细胞动力学的差异是持久的。这些结果表明，心肌细胞的动态行为（除了静态特性）取决于其起源的节段。
