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Fast‐to‐slow shift of muscle fiber‐type composition by dietary apple polyphenols in rats: Impact of the low‐dose supplementation
Author(s) -
Mizunoya Wataru,
Okamoto Shinpei,
Miyahara Hideo,
Akahoshi Mariko,
Suzuki Takahiro,
Do MaiKhoi Q.,
Ohtsubo Hideaki,
Komiya Yusuke,
Qahar Mulan,
Waga Toshiaki,
Nakazato Koichi,
Ikeuchi Yoshihide,
Anderson Judy E.,
Tatsumi Ryuichi
Publication year - 2017
Publication title -
animal science journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.606
H-Index - 38
eISSN - 1740-0929
pISSN - 1344-3941
DOI - 10.1111/asj.12655
Subject(s) - myosin , isometric exercise , endocrinology , medicine , hindlimb , atrophy , myoglobin , lower body , zoology , chemistry , leg muscle , muscle hypertrophy , anatomy , biology , physical medicine and rehabilitation , biochemistry
Our previous studies demonstrated that an 8‐week intake of 5% (w/w) apple polyphenol (APP) in the diet improves muscle endurance of young‐adult rats. In order to identify a lower limit of the dietary contribution of APP to the effect, the experiments were designed for lower‐dose supplementation (8‐week feeding of 0.5% APP in AIN‐93G diet) to 12‐week‐old male Sprague‐Dawley rats. Results clearly showed that the 0.5% APP diet significantly up‐regulates slower myosin‐heavy‐chain (MyHC) isoform ratios (IIx and IIa relative to total MyHC) and myoglobin expression in lower hind‐limb muscles examined ( P < 0.05). There was a trend to increased fatigue resistance detected from measurements of relative isometric plantar‐flexion force torque generated by a stimulus train delivered to the tibial nerve ( F (98, 1372) = 1.246, P = 0.0574). Importantly, there was no significant difference in the animal body‐phenotypes or locomotor activity shown as total moving distance in light and dark periods. Therefore, the present study encourages the notion that even low APP‐intake may increase the proportions of fatigue‐resistant myofibers, and has promise as a strategy for modifying performance in human sports and improving function in age‐related muscle atrophy.