title: Fast-to-slow shift of muscle fiber-type composition by dietary apple polyphenols in rats: Impact of the low-dose supplementation.
abstract: 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.
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Mizunoya
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Shinpei
authors.initials: S
authors.lastname: Okamoto
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Miyahara
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Akahoshi
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.|Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Mai-Khoi Q
authors.initials: MQ
authors.lastname: Do
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ohtsubo
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Komiya
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Mulan
authors.initials: M
authors.lastname: Qahar
authors.affiliation: Fundamental Research Laboratory, Asahi Breweries, Ltd., Moriya, Ibaraki, Japan.|Wakodo, Ltd., Chofu, Tokyo, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Waga
authors.affiliation: Department of Exercise Physiology, Graduate School of Health and Sport Sciences, Nippon Sport Science University, Tokyo, Japan.
authors.forename: Koichi
authors.identifier: http://orcid.org/0000-0002-2479-5771
authors.initials: K
authors.lastname: Nakazato
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Ikeuchi
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Judy E
authors.initials: JE
authors.lastname: Anderson
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Tatsumi
mesh_terms: D000818:Animals; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D027845:Malus; D018763:Muscle Fatigue / Q000187:drug effects; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D009211:Myoglobin / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism; D059808:Polyphenols / Q000008:administration & dosage* / Q000494:pharmacology*; D020033:Protein Isoforms; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D009211:Myoglobin; D059808:Polyphenols; D020033:Protein Isoforms; D018995:Myosin Heavy Chains
keywords: apple polyphenol; fiber type; locomotor activity; muscle endurance; myoglobin; myosin heavy chain