Davidowitz J, Philips G, Breinin G M
Tissue Cell. 1980;12(3):459-65. doi: 10.1016/0040-8166(80)90036-1.
The distribution of membrane--glycogen complexes along the length of individual muscle fibers was compared among three fiber populations in the orbital surface layer of rabbit superior rectus. These three populations were (a) 61 singly innervated fibers (SIFs), (b) 10 multiply innervated fibers of relatively constant 10 micrometer diameter (10 micrometer MIFs), and (c) 22 multiply innervated fibers which are of about 5 micrometer diameter toward the middle of their length and of about 15 micrometer diameter toward their proximal and distal segments (5--15 micrometer MIFs). The orbital surface layer was sampled by electron microscopy at 68 sequential locations. Membrane--glycogen complexes were not seen in any of the 1738 samples of the SIFs. In the MIFs, such complexes were observed in 14% of the 1541 samples. However, both the 10 micrometer MIFs and 5--15 micrometer MIFs displayed a preferential concentration of membrane--glycogen complexes toward their distal fiber portions, and such complexes were seen in about 50% of the MIF samples near the beginning of the muscle's distal third. In the distal portion of 5--15 micrometer MIFs, there was a direct relationship between their increasing fiber diameter and their increasing frequency of occurrence of membrane--glycogen complexes.
比较了兔上直肌眶表层中三个肌纤维群体沿单个肌纤维长度方向的膜-糖原复合物分布情况。这三个群体分别是：(a) 61条单突触支配纤维（SIFs）；(b) 10条直径相对恒定为10微米的多突触支配纤维（10微米MIFs）；(c) 22条多突触支配纤维，其长度中部直径约为5微米，近端和远端直径约为15微米（5-15微米MIFs）。通过电子显微镜在68个连续位置对眶表层进行取样。在1738个SIFs样本中均未发现膜-糖原复合物。在MIFs中，在1541个样本中有14%观察到了此类复合物。然而，10微米MIFs和5-15微米MIFs的膜-糖原复合物均在其纤维远端部分呈现出优先聚集的现象，并且在肌肉远端三分之一起始处附近约50%的MIFs样本中可见此类复合物。在5-15微米MIFs的远端部分，其纤维直径增加与膜-糖原复合物出现频率增加之间存在直接关系。
