ジチオトレイトールが高強度運動後の骨格筋筋小胞体のCa^<2+>-ATPase活性に及ぼす影響

EFFECT OF DITHIOTHREITOL ON Ca^<2+>-ATPase ACTIVITY OF SARCOPLASMIC RETICULUM IN RAT SKELETAL MUSCLE AFTER HIGH-INTENSITY EXERCISE

Tsuchimochi Hirotsugu

Inashima Shuichiro

Wada Masanobu

体力科学 : Japanese Journal of Physical Fitness and Sports Medicine

Although the precise mechanisms underlying the dysfunction of sarcoplasmic reticulum(SR) that occurs during skeletal muscle fatigue remain obscure, it has been hypothesized that it may be attributable to oxidation of critical sulfhydryl groups residing in SR Ca^<2+>-ATPase protein by endogenously produced reactive oxygen species. In order to test this hypothesis, SR Ca^<2+>-ATPase activities in the absence or presence of the disulfide reducing agent, dithiothreitol(DTT), were examined in muscle homogenates of the soleus muscles(SOL) and the superficial portions of the vastus lateralis muscles(VS) from the rat subjected to exhaustive running at 50 m/min on a 10% grade. Immediately after exercise, the catalytic activity of SR Ca^<2+>-ATPase was significantly depressed in VS, but not in SOL. The loss of SR Ca^<2+>-ATPase activity observed in VS was fully recovered after treatment with DTT(1 mM). These recovery effects of a potent disulfide reducing agent suggest that important proteins of SR Ca^<2+>-ATPase may be oxidized during high-intensity exercise and that the onset of muscular fatigue may be delayed by the improved function of the cellular antioxidant

sarcoplasmic reticulum

muscular fatigue

oxidation

sulfhydryl

reducing agent

Medical sciences [ 490 ]

jpn

日本体力医学会

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

[ISSN] 0039-906X

[NCID] AN00137986

[NAID] 110001918779