このエントリーをはてなブックマークに追加
ID 20793
file
creator
Matsuura, Natsue
Ozawa, Junya
Kai, Satoru
Sakakima, Harutoshi
Abiko, Sachiko
NDC
Medical sciences
abstract
To study injury and subsequent changes in skeletal muscles, the rat sciatic nerve was electrically stimulated at 50 Hz and muscle contraction was induced for 30 min. Muscle damage was classified into five types (hypercontraction, hyperstretching, Z band disorders, misalignment of myofilament and regions of scarce myofilaments) by electron microscopy and quantified by ultrastructural assessment. After electrical nerve stimulation, the percentages of the injured areas of the soleus muscle were 18.8 ± 15.8% (mean ± SD) at O h, 9.7 ± 1.0 0x1.3f1c4p-890t 6 h, 22.0 ± 23.6 0x0p+0t 12 h, 13.1 ± 3.2 0x0p+0t 24 h, 4.9 ± 6.0 0x0p+0t 3 days and 0.5 ± 0.4 0x0p+0t 7 days. At 0 h, the vast majority of ultrastructural alterations were sarcomere hypercontraction. At 6 h, hypercontraction was not recognizable and sarcomere hyperstretching and Z band disarrangement constituted the major findings. At 12 h, when the injury reaehed its maximum, myofilament disorganization and hyperstretching were predominant. At 24 h or afterwards, the injury began to decrease and recovered to almost normal conditions by 7 days. There were very few necrotic muscle fibers in all specimens. It is considered that the muscle lesions in the present study were reversible, and recovered through changes in various types of sarcomere alterations. Z band streaming and free ribosomes were frequently found at 12 and 24 h, which may indicate repair processes rather than newly formed lesions.
journal title
Archives of Histology and Cytology
volume
Volume 64
issue
Issue 4
start page
393
end page
400
date of issued
2001
publisher
International Society of Histology and Cytology
issn
0914-9465
ncid
publisher doi
pubmed id
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
relation url
department
Graduate School of Health Science