Hibernating Bears Conserve Muscle Strength and Maintain Fatigue Resistance

@article{Lohuis2007HibernatingBC,
  title={Hibernating Bears Conserve Muscle Strength and Maintain Fatigue Resistance},
  author={T. D. Lohuis and Henry J. Harlow and Thomas D. I. Beck and Paul Anthony Iaizzo},
  journal={Physiological and Biochemical Zoology},
  year={2007},
  volume={80},
  pages={257 - 269}
}
Black bears spend several months each winter confined to a small space within their den without food or water. In nonhibernating mammals, these conditions typically result in severe muscle atrophy, causing a loss of strength and endurance. However, an initial study indicated that bears appeared to conserve strength while denning. We conducted an in vivo, nonsubjective measurement of strength, resistance to fatigue, and contractile properties on the tibialis anterior muscle of six hibernating… 
Soleus muscle stability in wild hibernating black bears.
TLDR
The ability of the black bear to preserve the biochemical and performance characteristics of the soleus muscle during prolonged hibernation validates the ability of this mammal to resist skeletal muscle atrophy during hibernation.
Hibernating black bears (Ursus americanus) experience skeletal muscle protein balance during winter anorexia.
  • T. Lohuis, H. Harlow, T. Beck
  • Biology, Medicine
    Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology
  • 2007
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TLDR
The results agreed with a study that showed minimal skeletal muscle atrophy between seasons in wild black bears, and the half‐rise time in the twitch contractions increased in winter relative to summer samples, which is unexpected under disuse conditions.
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TLDR
It is suggested that metabolic rate alone can influence the rate of Muscle atrophy and that ectothermic vertebrates may have an intrinsic mechanism to resist muscle atrophy during seasonal periods of inactivity.
Comparative functional genomics of adaptation to muscular disuse in hibernating mammals
TLDR
A large‐scale gene expression screen in hind limb muscles comparing hibernating and summer‐active black bears and arctic ground squirrels using custom 9600 probe cDNA microarrays showed an elevated proportion of overexpressed genes involved in all stages of protein biosynthesis and ribosome biogenesis in muscle of both species during torpor of hibernation, suggesting induction of translation at different hibernation states.
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