Expression of myosin heavy chain isoforms in the postnatal mouse masseter muscle.
Expression of myosin heavy chain isoforms in the postnatal mouse masseter muscle.
复制标题
出生后小鼠咬肌中肌球蛋白重链亚型的表达。
DOI：
10.2535/ofaj.86.105
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
I. Sato
中科院分区：
文献类型：
--
作者：
Y. Miwa;M. Sunohara;I. Sato
我们研究了5 - 7周龄小鼠咬肌的特性。在咬肌中测量肌球蛋白重链（MyHC）亚型。5周龄和7周龄小鼠咬肌中均存在I型（强反应）、IIA型（中间反应）和IIB型（弱反应）3种肌纤维，3种肌纤维的酶活性可明显区分。在5周龄和7周龄的小鼠中，IIB型纤维所占比例最高（> 50%）。肌球蛋白slow和肌球蛋白IIb的mRNA水平在5周和7周之间显著增加。这些观察结果表明，肌纤维的大小，肌纤维类型和mRNA水平的MyHC亚型都有助于减少咬肌酶活性的功能适应性。
We investigated the properties of the masseter muscle in mice from five to seven weeks of age. Myosin heavy chain (MyHC) isoforms were measured in the masseter muscle. The three types of muscle fibers (Type I, strong reaction; Type IIA, intermediate reaction; and Type IIB, weak reaction) were all present in the masseter muscle in five-weeks-old mice and seven-weeks-old mice, the three types could be clearly distinguished by their enzyme activity. The percentage of Type IIB fibers (above 50%) was the highest among all fiber types both 5- and 7-weeks-old mice. The mRNA levels for myosin slow and myosin IIb increased significantly between 5 and 7 weeks. These observations suggest that muscle fiber size, muscle fiber types and mRNA levels of the MyHC isoforms all contribute to the diminished functional adaptability of enzyme activity in the masseter muscle.