Myofilament lattice spacing as a function of sarcomere length in isolated rat myocardium
Myofilament lattice spacing as a function of sarcomere length in isolated rat myocardium
复制标题
DOI：
10.1152/ajpheart.2000.279.5.h2568
复制
发表时间：
2000-11-01
影响因子：
4.8
通讯作者：
De Tombe, PP
中科院分区：
文献类型：
--
作者：
Irving, TC;Konhilas, J;De Tombe, PP
心脏的Frank-Starling关系作为其分子基础，随着肌节长度的增加，钙对肌原纤维的激活增加。有人认为，这种现象可能是由于肌丝以较长的长度移动得更近，从而增加了有利的肌动球蛋白相互作用的可能性，导致钙敏感性增加。因此，我们已经开发了一种装置，以获得准确的测量心肌肌丝间距（同步加速器X射线衍射）的肌节长度的函数（视频显微镜）在心脏的工作范围内，使用皮肤以及完整的大鼠小梁作为模型系统。在这两个系统中，晶格间距显着减少肌节长度的增加。此外，晶格间距在完整的肌肉是显着小于在去皮的肌肉在所有肌节长度的研究。这些观察结果是一致的假设，晶格间距的基础上的长度依赖性激活心肌。
The Frank-Starling relationship of the heart has, as its molecular basis, an increase in the activation of myofibrils by calcium as the sarcomere length increases. It has been suggested that this phenomenon may be due to myofilaments moving closer together at longer lengths, thereby enhancing the probability of favorable actomyosin interaction, resulting in increased calcium sensitivity. Accordingly, we have developed an apparatus so as to obtain accurate measurements of myocardial interfilament spacing (by synchrotron X-ray diffraction) as a function of sarcomere length (by video microscopy) over the working range of the heart, using skinned as well as intact rat trabeculas as model systems. In both these systems, lattice spacing decreased significantly as sarcomere length was increased. Furthermore, lattice spacing in the intact muscle was significantly smaller than that in the skinned muscle at all sarcomere lengths studied. These observations are consistent with the hypothesis that lattice spacing underlies length-dependent activation in the myocardium.