EXCITATION-CONTRACTION COUPLING IN SKELETAL MUSCLE

目前认为，Ca2+释放的机制，从 肌浆网（SR）的运作，在骨骼肌，控制下， 横小管系统的膜电位。的帮助下 电生理和光学技术，建议调查 在两个水平上调节细胞内Ca 2+浓度： SR可能引发肌浆改变的机制 [Ca2+]在释放过程的激活过程中，和B）机制 局部Ca 2+释放SR向其余部分的传播 肌浆这些实验旨在获得关于关键的 关于这些过程可能提出的问题：SR是否发布 Ca2+通过一个大的或小的渗透性？的作用是什么 钙诱导钙释放过程Ca2+释放过程 位于青蛙骨骼肌纤维的Z线上我在那里陡峭 肌节内（Ca2+）I梯度通过 Ca2+进入肌原纤维间隙？其中几个问题的答案 几十年来一直悬而未决然而，技术 快速闪光光解、钙离子探测和成像技术的进展 使它们现在可以通过实验来回答。结果 可能会导致一个新的画面的发展， 今天的肌肉生理学可以想象，治疗肌肉的方法 由于缺乏准确的定义， 细胞内Ca2+的调节所涉及的问题，可能是 鉴于这些结果。最后，由于该应用程序涉及 关于细胞内Ca2+调节的一般问题， 结论不仅适用于骨骼肌、心肌和平滑肌， 但几乎对任何细胞都是如此，因为胞质Ca 2+介导了大量的细胞内钙离子， 生物学中的细胞过程。

It is currently believed that the mechanism of Ca2+ release from the sarcoplasmic reticulum (SR) operates, in skeletal muscle, under control of the membrane potential of the transverse tubular system. With the aid of electrophysiological and optical techniques, it is proposed to investigate the regulation of the intracellular Ca2+ concentration at two levels: a) the mechanisms by which the SR may initiate the changes in myoplasmic [Ca2+] during the activation of the release process and b) the mechanisms of propagation of the localized Ca2+ release SR to the rest of the myoplasm. The experiments aim to obtain precise information about critical questions that can be raised about these processes: Does the SR releases Ca2+ by means of a large or a small permeability? What is the role of the calcium-induce-calcium release process? Is the Ca2+ release process localized at the Z lines in frog skeletal muscle fibers? Me there steep intra-sarcomeric (ca2+i gradients that dissipate rapidly by diffusion of Ca2+ to the myofibrillar space? The answers to several of these questions have been pending in the field since decades. Nevertheless, technological advances in fast flash photolysis, Ca2+ detection, and imaging techniques make it possible for them to be answered experimentally now. The results may lead to the development of a new picture in the way that we understand muscle physiology today. It is conceivable that the cure for muscle diseases not well understood yet due to the lack of an accurate definition of the problems involved in the regulation of intracellular Ca2+, may be reached in view of these results. Finally, since this application deals with general questions about intracellular Ca2+ regulation, the conclusions will not only apply to skeletal, cardiac, and smooth muscle, but to almost any cell, since cytosolic Ca2+ mediates a large variety of cellular processes in biology.