TY - JOUR
T1 - Improvement of endurance based on muscle fiber-type composition by treatment with dietary apple polyphenols in rats
AU - Mizunoya, Wataru
AU - Miyahara, Hideo
AU - Okamoto, Shinpei
AU - Akahoshi, Mariko
AU - Suzuki, Takahiro
AU - Do, Mai Khoi Q.
AU - Ohtsubo, Hideaki
AU - Komiya, Yusuke
AU - Lan, Mu
AU - Waga, Toshiaki
AU - Iwata, Akira
AU - Nakazato, Koichi
AU - Ikeuchi, Yoshihide
AU - Anderson, Judy E.
AU - Tatsumi, Ryuichi
N1 - Publisher Copyright:
© 2015 Mizunoya et al.
PY - 2015/7/29
Y1 - 2015/7/29
N2 - 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. Animalgrowth 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 fibertype 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.
AB - 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. Animalgrowth 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 fibertype 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.
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U2 - 10.1371/journal.pone.0134303
DO - 10.1371/journal.pone.0134303
M3 - Article
C2 - 26222548
AN - SCOPUS:84941730209
SN - 1932-6203
VL - 10
JO - PloS one
JF - PloS one
IS - 7
M1 - 134303
ER -
