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ID 26005
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title alternative
RELATIONSHIP BETWEEN OXIDATION OF MYOFIBRILLAR PROTEINS AND CONTRACTILE PROPERTIES IN SOLEUS MUSCLES FROM HYPERTHYROID RAT
creator
Yamada, Takashi
Mishima, Takaaki
Sakamoto, Makoto
Sugiyama, Minako
Matsunaga, Satoshi
subject
reactive oxygen species
hyperthyroidism
specific force reduction
redox status
NDC
Medical sciences
abstract
We tested the hypothesis that a force reduction in soleus muscles from hyperthyroid rats would be associated with oxidative modification of myofibrillar proteins. Daily injection of thyroid hormone [3,5,3'-triiodo-L-thyronine (T_3)] for 21 days depressed isometric forces in whole soleus muscle across a range of stimulus frequencies (1, 10, 20, 40, 75 and 100Hz) (P<0.05). In fiber bundles, hyperthyroidism also led to pronounced reductions (P<0.05) in both K^+- and 4-chloro-m-cresol-induced contracture forces. The degrees of the reductions were similar between these two contractures. These reductions in force production were accompanied by a remarkable increment (103% ; P<0.05) in carbonyl groups comprised in myofibrillar proteins. In additional experiments, we have also tested the efficacy of carvedilol, a non-selective β_1-β_2-blocker that possesses anti-oxidative properties. Treatment with carvedilol prevented T_3-induced oxidation of myofibrillar proteins. However, carvedilol did not improve the hyperthyroid-induced reductions in force production. These data suggest that oxidative modification of myofibrillar proteins may not account for the reductions in force production of hyperthyroid rat soleus muscle.
journal title
体力科学 : Japanese Journal of Physical Fitness and Sports Medicine
volume
Volume 56
issue
Issue 5
start page
473
end page
480
date of issued
2007-10-01
publisher
日本体力医学会
issn
0039-906X
ncid
language
jpn
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
日本体力医学会
本文データは学協会の許諾に基づきCiNiiから複製したものである
relation url
department
Graduate School of Integrated Arts and Sciences