The Journal of Physiological Sciences

, Volume 68, Issue 3, pp 269–280 | Cite as

Long-term resistance exercise-induced muscular hypertrophy is associated with autophagy modulation in rats

  • Insu Kwon
  • Yongchul Jang
  • Joon-Yong Cho
  • Young C. Jang
  • Youngil Lee
Original Paper


Elevation of anabolism and concurrent suppression of catabolism are critical metabolic adaptations for muscular hypertrophy in response to resistance exercise (RE). Here, we investigated if RE-induced muscular hypertrophy is acquired by modulating a critical catabolic process autophagy. Male Wistar Hannover rats (14 weeks old) were randomly assigned to either sedentary control (SC, n = 10) or resistance exercise (RE, n = 10). RE elicited significant hypertrophy of flexor digitorum profundus (FDP) muscles in parallel with enhancement in anabolic signaling pathways (phosphorylation of AKT, mTOR, and p70S6K). Importantly, RE-treated FDP muscle exhibited a significant decline in autophagy evidenced by diminished phosphorylation levels of AMPK, a decrease in LC3-II/LC3-I ratio, an increase in p62 level, and a decline in active form of lysosomal protease CATHEPSIN L in the absence of alterations of key autophagy proteins: ULK1 phosphorylation, BECLIN1, and BNIP3. Our study suggests that RE-induced hypertrophy is achieved by potentiating anabolism and restricting autophagy-induced catabolism.


Resistance exercise Autophagy Skeletal muscle Hypertrophy 



This project was supported by a grant from the University of West Florida though the Office of Research and Sponsored Programs (#164336) and UWF Florida Research Fellowship to YL (CF6672).

Author contributions

I.K. and Y.J. collected and analyzed data; I.K., Y.J., Y.C.J. and Y.L. interpreted results; I.K. and Y.J. prepared the table and figures; I.K. and Y.L. drafted the manuscript; I.K., Y.J., J-Y. C., Y.C.J., and Y.L. edited and revised the manuscript; I.K., Y.J., J-Y. C., J.Y.C., and Y.L. approved the final version of the manuscript; I.K. and Y.L. developed the conception and design of research.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no competing interests.


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Copyright information

© The Physiological Society of Japan and Springer Japan 2017

Authors and Affiliations

  • Insu Kwon
    • 1
  • Yongchul Jang
    • 1
  • Joon-Yong Cho
    • 2
  • Young C. Jang
    • 3
  • Youngil Lee
    • 1
  1. 1.Molecular and Cellular Exercise Physiology Laboratory, Department of Exercise Science and Community Health, College of HealthUniversity of West FloridaPensacolaUSA
  2. 2.Exercise Biochemistry LaboratoryKorea National Sport UniversitySeoulKorea
  3. 3.School of Applied Physiology and Parker H. Petit Institute for Bioengineering and BioscienceGeorgia Institute of TechnologyAtlantaUSA

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