Salmons S, Gale D R, Sréter F A
J Anat. 1978 Sep;127(Pt 1):17-31.
The criteria which serve to distinguish the slow from the fast type of mammalian skeletal muscle include differences at the ultrastructural level, in particular differences in Z disc morphology and mitochondrial content. If a fast muscle is subjected to sustained low frequency impulse activity similar to that normally received by a slow muscle, its physiological and biochemical properties become indistinguishable from those of a slow muscle. In the present study we have examined the fine structure of fast muscles stimulated in this way. The thickness of Z discs was significantly greater than that of control fast muscles and indistinguishable from that of slow muscles. Mitochondrial profiles, seen only infrequently in control fast muscles, were abundant in their stimulated counterparts. The regulatory influence of impulse activity on the differentiation of skeletal muscle thus extends to some of its most characteristic ultrastructural features.
用于区分哺乳动物慢肌和快肌类型的标准包括超微结构水平上的差异，特别是Z盘形态和线粒体含量的差异。如果快肌受到与慢肌通常所接受的相似的持续低频冲动活动，其生理和生化特性就会变得与慢肌难以区分。在本研究中，我们检查了以这种方式刺激的快肌的精细结构。Z盘的厚度明显大于对照快肌，且与慢肌的厚度无差异。线粒体轮廓在对照快肌中很少见，而在受刺激的快肌中大量存在。因此，冲动活动对骨骼肌分化的调节影响延伸到了其一些最具特征的超微结构特征。
