Boyett M R, Frampton J E, Kirby M S
Department of Physiology, University of Leeds.
Exp Physiol. 1991 Mar;76(2):259-70. doi: 10.1113/expphysiol.1991.sp003492.
The length and width of rat and ferret ventricular myocytes have been measured using a linear photodiode array; the volume of the myocytes has been calculated based on the assumption that the cells were elliptical cylinders. During a twitch contraction, there was a decrease in cell length, but no significant change in the calculated cell volume, because the cells increased in width. Inotropic interventions not only resulted in a greater shortening of the cell during each contraction, but also a greater increase in cell width. Changes in cell length, width and volume on changing the osmotic strength of the bathing solution have also been investigated. The increase in volume in hypotonic solution, and the decrease in hypertonic solution, were the result of changes in the cell width; there were no significant changes in the cell length. It is concluded from the latter experiment that the lateral compliance of a cell is greater than its longitudinal compliance, and, therefore, during a twitch contraction, when the cell shortens, the displacement of the cell contents from the two ends of the cell and the expansion of the cell laterally will not act as a large force to oppose shortening.
已使用线性光电二极管阵列测量了大鼠和雪貂心室肌细胞的长度和宽度；基于细胞为椭圆圆柱体的假设计算了肌细胞的体积。在一次单收缩过程中，细胞长度减小，但计算出的细胞体积无显著变化，因为细胞宽度增加。变力干预不仅导致每次收缩时细胞缩短幅度更大，而且细胞宽度增加幅度也更大。还研究了改变浴液渗透压强度时细胞长度、宽度和体积的变化。低渗溶液中细胞体积增加，高渗溶液中细胞体积减小，这是细胞宽度变化的结果；细胞长度无显著变化。从后一项实验得出的结论是，细胞的横向顺应性大于其纵向顺应性，因此，在单收缩过程中，当细胞缩短时，细胞内容物从细胞两端的位移以及细胞的横向扩张不会产生很大的力来对抗缩短。
