Skeletal muscle function and fibre types: the relationship between occlusal function and the phenotype of jaw-closing muscles in human.
Skeletal muscle function and fibre types: the relationship between occlusal function and the phenotype of jaw-closing muscles in human.
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DOI：
10.1093/ortho/27.1.15
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发表时间：
2000-03-01
影响因子：
1.3
通讯作者：
Morris, T J
中科院分区：
文献类型：
--
作者：
Sciote, J J;Morris, T J
哺乳动物骨骼肌细胞由重复的肌节单元组成，其中分别含有肌球蛋白和肌动蛋白的粗丝和细丝。仅当存在 Mg-ATP 和 Ca(2+) 时才可能激发肌球蛋白 ATP 酶。骨骼肌纤维根据其所含的肌球蛋白亚型可分为几种类型。已知哺乳动物骨骼肌中存在九种肌球蛋白重链亚型，包括 I 型、IIA 型、IIB 型、IIX 型、IIM 型、α 型、新生儿型、胚胎型和眼外型。健康成人四肢骨骼肌含有 I、IIA、IIB 和 IIX 型肌球蛋白重链。大多数食肉动物和灵长类动物的下颌闭合肌肉具有 IIM 型或“II 型咀嚼”肌球蛋白重链的组织特异性表达。然而，成人的下颌闭合肌肉不含 IIM 肌球蛋白。相反，它们表达 I 型、IIA 型、IIX 型（如在人类四肢肌肉中）以及通常在发育中或心肌中表达的肌球蛋白。人类下颌闭合肌纤维的形态也很不寻常，因为 II 型纤维的直径小于 I 型纤维，除非功能增强和肥大。本文描述了纤维类型和运动单位功能与人类咬合和咀嚼活动变化的关系。审稿的科学论文
Mammalian skeletal muscle cells are composed of repeated sarcomeric units containing thick and thin filaments of myosin and actin, respectively. Excitation of the myosin ATPase enzyme is possible only with presence of Mg-ATP and Ca(2+). Skeletal muscle fibres may be classified into several types according to the isoform of myosin they contain. Nine isoforms of myosin heavy chain are known to exist in mammalian skeletal muscle including type I, IIA, IIB, IIX, IIM, alpha, neonatal, embryonic, and extra-ocular. Healthy adult human limb skeletal muscle contains type I, IIA, IIB, and IIX myosin heavy chains. The jaw-closing muscles of most carnivores and primates have tissue-specific expression of the type IIM or 'type II masticatory' myosin heavy chain. Adult human jaw-closing muscles, however, do not contain IIM myosin. Rather, they express type I, IIA, IIX (as in human limb muscle), and myosins typically expressed in developing or cardiac muscle. The morphology of human jaw-closing muscle fibres is also unusual in that the type II fibres are of smaller diameter that type I fibres, except in cases of increased function and hypertrophy. This paper describes the relationship of fibre types and motor unit function to changes in human occlusion and masticatory activity. Refereed Scientific Paper