Connective tissue changes in immobilised muscle.
Connective tissue changes in immobilised muscle.
复制标题
固定肌肉中的结缔组织发生变化。
作者：
P. Williams;G. Goldspink
固定在缩短位置的肌肉纤维长度的减少伴随着肌肉顺应性的降低。由于肌内结缔组织框架通过拉伸来分散被动施加在肌肉上的力，因此决定研究固定肌肉中结缔组织的数量和分布。对不同时间段固定在缩短位置的肌肉羟脯氨酸含量的生化分析表明，胶原蛋白与肌纤维组织的比例有所增加。这种情况发生在固定的最初几天，在肌节出现任何显着损失之前。因此，结缔组织的增加似乎是直接由固定引起的，而不是由纤维缩短后结缔组织的重新分布引起的。对天狼星红染色的肌肉切片的结缔组织进行详细的组织学分析表明，固定肌肉中结缔组织的早期增加发生在肌束膜而不是肌内膜，尽管经过较长时间的固定后，肌内膜也会增厚。对正常肌肉肌束膜的超微结构分析表明，胶原纤维与肌纤维所成的角度随肌肉的拉伸状态而变化；当肌肉缩短时，角度比肌肉拉长时更大。在固定的肌肉中，发现胶原纤维与肌纤维轴的排列方式比正常肌肉中的更锐角。这预计会影响肌肉的顺应性。所描述的实验表明，固定肌肉的硬度增加可能是由于结缔组织的量和质的变化造成的。
The reduction in fibre length of muscles immobilised in a shortened position is accompanied by reduced compliance of the muscle. Since the intramuscular connective tissue framework distributes the forces passively imposed on a muscle by stretching, it was decided to investigate the amount and distribution of connective tissue in immobilised muscles. Biochemical analysis of the hydroxyproline content of muscles immobilised in the shortened position for different periods of time showed an increase in the ratio of collagen to muscle fibre tissue. This occurred during the first few days of immobilisation, before there was any significant loss of sarcomeres. Thus the increase in connective tissue appeared to result directly from immobilisation rather than from redistribution of connective tissue, following shortening of the fibres. A detailed histological analysis of muscle sections stained for connective tissue with Sirius Red showed that the early increase in connective tissue in immobilised muscles occurred in the perimysium rather than the endomysium, although after a longer period of immobilisation there was also a thickening of the endomysium. Ultrastructural analysis of the perimysium in normal muscle showed that the angle the collagen fibres made with the muscle fibres changed with the state of stretch of the muscle; when the muscle was shortened, the angle was larger than when the muscle was lengthened. In immobilised muscle, collagen fibres were found to be arranged at a more acute angle to the axis of the muscle fibres than was found in normal muscle; this would be expected to affect the compliance of the muscle. The experiments described indicate that the increased stiffness of immobilised muscles could result from both quantitative and qualitative changes in the connective tissue.