title: Improvement of Endurance Based on Muscle Fiber-Type Composition by Treatment with Dietary Apple Polyphenols in Rats.
abstract: A recent study demonstrated a positive effect of apple polyphenol (APP) intake on muscle endurance of young-adult animals. While an enhancement of lipid metabolism may be responsible, in part, for the improvement, the contributing mechanisms still need clarification. Here we show that an 8-week intake of 5% (w/w) APP in the diet, up-regulates two features related to fiber type: the ratio of myosin heavy chain (MyHC) type IIx/IIb and myoglobin protein expression in plantaris muscle of 9-week-old male Fischer F344 rats compared to pair-fed controls (P < 0.05). Results were demonstrated by our SDS-PAGE system specialized for MyHC isoform separation and western blotting of whole muscles. Animal-growth profiles (food intake, body-weight gain, and internal-organ weights) did not differ between the control and 5% APP-fed animals (n = 9/group). Findings may account for the increase in fatigue resistance of lower hind limb muscles, as evidenced by a slower decline in the maximum isometric planter-flexion torque generated by a 100-s train of electrical stimulation of the tibial nerve. Additionally, the fatigue resistance was lower after 8 weeks of a 0.5% APP diet than after 5% APP, supporting an APP-dose dependency of the shift in fiber-type composition. Therefore, the present study highlights a promising contribution of dietary APP intake to increasing endurance based on fiber-type composition in rat muscle. Results may help in developing a novel strategy for application in animal sciences, and human sports and age-related health sciences.
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Hakozaki, 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, Hakozaki, 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, Hakozaki, 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, Hakozaki, 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, Hakozaki, Fukuoka, 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, Hakozaki, Fukuoka, Japan.
authors.forename: Mai-Khoi Q
authors.initials: MK
authors.lastname: Do
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Hakozaki, 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, Hakozaki, 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, Hakozaki, Fukuoka, Japan.
authors.forename: Mu
authors.initials: M
authors.lastname: Lan
authors.affiliation: Fundamental Research Laboratory, Asahi Breweries, Ltd., Moriya, Ibaraki, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Waga
authors.affiliation: Department of Physical Therapy, Faculty of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Iwata
authors.affiliation: Department of Exercise Physiology, Graduate School of Health and Sport Sciences, Nippon Sport Science University, Fukasawa, Tokyo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakazato
authors.affiliation: Department of Animal and Marine Bioresource Sciences, Graduate School of Agriculture, Kyushu University, Hakozaki, Fukuoka, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Ikeuchi
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Manitoba, Winnipeg, MB, 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, Hakozaki, Fukuoka, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Tatsumi
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D027845:Malus; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D009211:Myoglobin / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism; D010807:Physical Endurance / Q000502:physiology*; D064209:Phytochemicals / Q000008:administration & dosage*; D059808:Polyphenols / Q000008:administration & dosage*; D020033:Protein Isoforms / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D024744:Skeletal Muscle Myosins / Q000378:metabolism
chemical_list: D009211:Myoglobin; D064209:Phytochemicals; D059808:Polyphenols; D020033:Protein Isoforms; D024744:Skeletal Muscle Myosins; D018995:Myosin Heavy Chains