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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Research
article
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EFFECT OF TAURINE SUPPLEMENTATION ON THE ALTERATIONS IN AMINO ACID CONTENT IN SKELETAL MUSCLE WITH EXERCISE IN RAT |
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Keisuke Ishikura1, Teruo Miyazaki3, Song-Gyu Ra1, Shoji Endo2, Yusuke Nakamura2, Takashi Matsuzaka1, Shumpei Miyakawa1 and Hajime Ohmori1  |
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1Graduate School of Comprehensive Human Sciences, and 2School of Health and Physical Education, University of Tsukuba, Tsukuba, 3Department of Development for Community Medicine, Tokyo Medical University, Ami, Japan |
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© Journal of Sports Science and Medicine (2011) 10, 306 - 314 |
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| ABSTRACT | |||
| Taurine included abundantly in skeletal muscle, particularly in
the slow-twitch fibers, enhances exercise performance. However, the exact
mechanisms for this effect have been unclear. The present study investigated
the influence of taurine supplementation on amino acids profile in skeletal
muscles as one of mechanisms in the enhancement of exercise performance
induced by taurine. In the rats that received taurine solution, amino acids
concentrations were comprehensively quantified in two portions with different
fiber compositions in the fast-twitch fiber dominant (FFD) gastrocnemius
muscle after 2 weeks, and in the gastrocnemius and additional other FFD
muscles, liver, and plasma with exhausted exercise after 3 weeks. In the
FFD muscles after 2 weeks, a common phenomenon that decreased concentrations
of threonine (-16%), serine (-15~-16%), and glycine (-6~-16%) were observed,
and they are categorized in the pyruvate precursors for hepatic gluconeogenesis
rather than biosynthesis, polar, and side-chain structures. The decreases
in the three amino acids were significantly emphasized after an additional
week of taurine supplementation in the FFD muscles (p values in three amino
acids in these tissues were less than 0.001-0.05), but not in the liver
and plasma, accompanied with significantly increase of running time to exhaustion
(p <0.05). In contrast, the three amino acids (threonine and serine;
p < 0.05, glycine; p < 0.01) and alanine (p < 0.01) in the liver
were significantly decreased and increased, respectively, following the
exhaustive exercise. In conclusion, the taurine-induced reductions of these
amino acids in skeletal muscle might be one of the mechanisms which underpin
the enhancement of exercise performance by taurine. Key words: Serine, glycine, threonine, gluconeogenic precursor, treadmill. . |
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