Fiber Type Composition of the Sternomastoid and Diaphragm Muscles of Dystrophin-Deficient mdx Mice
Fiber Type Composition of the Sternomastoid and Diaphragm Muscles of Dystrophin-Deficient mdx Mice
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DOI：
10.1002/ar.21224
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发表时间：
2010-10-01
影响因子：
2
通讯作者：
Minatel, Elaine
中科院分区：
文献类型：
--
作者：
Guido, Anderson Neri;Rocha Campos, Gerson Eduardo;Minatel, Elaine
The muscle fiber phenotype is mainly determined by motoneuron innervation and changes in neuromuscular interaction alter the muscle fiber type. In dystrophin-deficient mdx mice, changes in the molecular assembly of the neuromuscular junction and in nerve terminal sprouting occur in the sternomastoid (STN) muscle during early stages of the disease. In this study, we were interested to see whether early changes in neuromuscular assembly are correlated with alterations in fiber type in dystrophic STN at 2 months of age. A predominance of hybrid fast myo-fibers (about 52% type IIDB) was observed in control (C57B1/10) STN. In mdx muscle, the lack of dystrophin did not change this profile (about 54% hybrid type IIDB). Pure fast type HD fibers predominated in normal and dystrophic diaphragm (DIA; about 39% in control and 30% in mdx muscle) and a population of slow Type I fibers was also present (about 10% in control and 13% in mdx muscle). In conclusion, early changes in neuromuscular assembly do not affect the fiber type composition of dystrophic STN. In contrast to the pure fast fibers of the more affected DIA, the hybrid phenotype of the STN may permit dynamic adaptations during progression of the disease. Anat Rec, 293:1722-1728, 2010. (C) 2010 Wiley-Liss, Inc.
