Purslow Peter P
Department of Biological Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK.
Comp Biochem Physiol A Mol Integr Physiol. 2002 Dec;133(4):947-66. doi: 10.1016/s1095-6433(02)00141-1.
The amount of intramuscular connective tissue (IMCT) and its morphological distribution is highly variable between muscles of differing function. The functional roles of this component of muscle have been poorly understood, but a picture is gradually emerging of the central role this component has in growth, transmission of mechanical signals to muscle cells and co-ordination of forces between fibres within a muscle. The aim of this review is to highlight recent advances that begin to show the functional significance of some of the variability in IMCT. IMCT has a number of clearly defined roles. It patterns muscle development and innervation, and mechanically integrates the tissue. In developing muscles, proliferation and growth of muscle cells is stimulated and guided by cell-matrix interactions. Recent work has shown that the topography of collagen fibres is an important signal. The timing and rates of expression of connective tissue proteins also show differences between muscles. Discussion of mechanical roles for IMCT has traditionally been limited to the passive elastic response of muscle. However, it is now clear that IMCT provides a matrix to integrate the contractile function of the whole tissue. Mechanical forces are co-ordinated and passed between adjacent muscle cells via cell-matrix interactions and the endomysial connective tissue that links the cells together. An emerging concept is that division of a muscle into fascicles by the perimysial connective tissue is related to the need to accommodate shear strains as muscles change shape during contraction and extension.
不同功能的肌肉之间，肌内结缔组织（IMCT）的数量及其形态分布差异很大。人们对肌肉这一组成部分的功能作用了解甚少，但它在生长、将机械信号传递给肌肉细胞以及协调肌肉内纤维间力量方面所起的核心作用正逐渐明晰。本综述的目的是强调一些最新进展，这些进展开始揭示IMCT某些变异性的功能意义。IMCT具有一些明确的作用。它决定肌肉发育和神经支配模式，并在机械方面整合组织。在发育中的肌肉里，肌肉细胞的增殖和生长受细胞与基质相互作用的刺激和引导。最近的研究表明，胶原纤维的形态是一个重要信号。结缔组织蛋白表达的时间和速率在不同肌肉之间也存在差异。传统上，关于IMCT机械作用的讨论仅限于肌肉的被动弹性反应。然而，现在很清楚的是，IMCT提供了一个整合整个组织收缩功能的基质。机械力通过细胞与基质的相互作用以及连接细胞的肌内膜结缔组织在相邻肌肉细胞之间协调和传递。一个新出现的概念是，肌周结缔组织将肌肉分成肌束与肌肉在收缩和伸展过程中改变形状时适应剪切应变的需求有关。
