Kasuta S
Department of Prosthodontics II, Faculty of Dentistry, Tokyo Medical and Dental University.
Kokubyo Gakkai Zasshi. 1995 Jun;62(2):254-68. doi: 10.5357/koubyou.62.254.
Histochemical and electron microscopic observations were made on normal and denervated masseter muscles of mice to elucidate differences of characteristics between the masticatory muscles and other skeletal muscles. The three types of muscle fibers were classified by means of Succinic dehydrogensae (SDH) reaction. In masseter muscles of normal adult mice, the three types of fibers, that is, high SDH activity fibers, intermediate SDH activity fibers and low SDH activity fibers, were recognized. More oxidative fibers in the deep portion of masseter muscles were found than that in the superior portion, which suggest that each portion has its own functional role. It is generally believed that denervation gradually causes atrophy in skeletal muscles. On the other hand, denervated masseter muscles of mice clearly showed different reactions which had two phases. In the first phase right after denervation, many masseter muscle fibers were degenerated, necrosed and regenerated. A few weeks later, in the second phase, muscle fibers remained immature, denervation atrophy was occurred, and dense connective tissue was proliferated. The other side of nondenervated masseter muscle was not influenced by denervated ones.
对小鼠正常和去神经支配的咬肌进行了组织化学和电子显微镜观察，以阐明咀嚼肌与其他骨骼肌之间特征的差异。通过琥珀酸脱氢酶（SDH）反应对三种类型的肌纤维进行分类。在正常成年小鼠的咬肌中，可识别出三种类型的纤维，即高SDH活性纤维、中等SDH活性纤维和低SDH活性纤维。咬肌深部的氧化纤维比上部更多，这表明各部分具有其自身的功能作用。一般认为去神经支配会逐渐导致骨骼肌萎缩。另一方面，小鼠去神经支配的咬肌明显表现出不同的反应，分为两个阶段。在去神经支配后的第一阶段，许多咬肌纤维发生变性、坏死和再生。几周后，在第二阶段，肌纤维仍不成熟，发生去神经支配性萎缩，并且致密结缔组织增生。未去神经支配的咬肌一侧不受去神经支配咬肌的影响。
