Zenker W, Sandoz P A, Neuhuber W
Institute of Anatomy, University of Zürich, Switzerland.
Anat Embryol (Berl). 1988;177(3):235-43. doi: 10.1007/BF00321134.
The sternomastoid muscle of the rat is divided into a white (dominated by fast-glycolytic twitch fibers) and a red (dominated by fast oxidative-glycolytic twitch fibers, but also containing slow-oxidative twitch fibers) compartment. Previous reports on exclusive location of muscle spindles in the red portion were confirmed. On the basis of anterograde labeling with horseradish peroxidase-wheat germ agglutinine conjugate (WGA-HRP) it was shown in this study that, in addition to muscle spindle compartmentalisation, there was also an exclusive occurrence of tendon organs in the red part of the muscle; moreover, fine afferents (III- and IV-afferents) were mainly distributed to this portion as well. Radioimmunassay studies revealed that this part of the muscle contained twice as much substance P as the white part. It could be shown by acetylcholinesterase (AChE) histochemistry that the myelinated fibers of the white branch to the muscle exclusively displayed high enzyme activity which is characteristic for motor fibers; on the other hand, in the branch to the red portion two classes of AChE-positive fibers were found: a large one with a peak in the alpha-range, and a small one with a peak in the gamma-range. In addition, there was also a group of enzyme-negative (sensory) fibers. These results also indicate the red portion of the sternomastoid muscle to be its "sensory compartment".
大鼠的胸锁乳突肌分为白色部分（以快速糖酵解型快肌纤维为主）和红色部分（以快速氧化糖酵解型快肌纤维为主，但也含有慢氧化型快肌纤维）。先前关于肌梭仅位于红色部分的报道得到了证实。在本研究中，基于用辣根过氧化物酶 - 小麦胚凝集素共轭物（WGA - HRP）进行的顺行标记显示，除了肌梭的分区化之外，腱器官也仅存在于肌肉的红色部分；此外，细传入纤维（III型和IV型传入纤维）也主要分布于该部分。放射免疫分析研究表明，该部分肌肉中P物质的含量是白色部分的两倍。通过乙酰胆碱酯酶（AChE）组织化学可以看出，支配白色部分肌肉的分支中的有髓纤维仅表现出运动纤维特有的高酶活性；另一方面，在支配红色部分的分支中发现了两类AChE阳性纤维：一类大的在α范围内有峰值，一类小的在γ范围内有峰值。此外，还有一组酶阴性（感觉）纤维。这些结果也表明胸锁乳突肌的红色部分是其“感觉区”。
