Journal of Biomedical Science

, Volume 11, Issue 6, pp 838–846

Effect of prolonged intermittent hypoxia and exercise training on glucose tolerance and muscle GLUT4 protein expression in rats

  • Li-Ling Chiu
  • Shih-Wei Chou
  • Yu-Min Cho
  • Hsin-Yi Ho
  • John L. Ivy
  • Desmond Hunt
  • Paulus S. Wang
  • Chia-Hua Kuo
Original Paper

DOI: 10.1007/BF02254369

Cite this article as:
Chiu, LL., Chou, SW., Cho, YM. et al. J Biomed Sci (2004) 11: 838. doi:10.1007/BF02254369

Abstract

We compared the chronic effect of intermittent hypoxia and endurance training on the glucose tolerance and GLUT4 protein expression in rat skeletal muscle. Thirty-two Sprague-Dawley rats were matched for weight and assigned to one of the following four groups: control, endurance training, hypoxia, or hypoxia followed by endurance training. Hypoxic treatment consisted of breathing 14% O2 for 12 h/day under normobaric conditions, and the training protocol consisted of making animals swim 2 times for 3 h/day. At the end of the 3rd week, an oral glucose tolerance test (OGTT) was performed 16 h after treatments. At the end of the 4th week, GLUT4 protein, mRNA, and glycogen storage in skeletal muscle were determined. Endurance training significantly improved OGTT results. Glycogen content and GLUT4 protein expression in the plantaris and red gastrocnemius, but not in the soleus or white gastrocnemius muscles, were also elevated. Chronic intermittent hypoxia also improved OGTT results, but did not alter GLUT4 protein expression. Additionally, hypoxia followed by exercise training produced significant increases in GLUT4 protein and mRNA in a greater number of muscles compared to endurance training alone. Both exercise training and hypoxia significantly reduced body mass, and an additive effect of both treatments was found. In conclusion, chronic intermittent hypoxia improved glucose tolerance in the absence of increased GLUT4 protein expression. This treatment facilitated the exercise training effect on muscle GLUT4 expression and glycogen storage. These new findings open the possibility of utilizing intermittent hypoxia, with or without exercise training, for the prevention and clinical treatment of type 2 diabetes or insulin resistance.

Key Words

Body mass Diabetes Glycogen Insulin resistance Skeletal muscle 

Copyright information

© National Science Council 2004

Authors and Affiliations

  • Li-Ling Chiu
    • 5
  • Shih-Wei Chou
    • 1
  • Yu-Min Cho
    • 5
  • Hsin-Yi Ho
    • 5
  • John L. Ivy
    • 3
  • Desmond Hunt
    • 4
  • Paulus S. Wang
    • 2
  • Chia-Hua Kuo
    • 5
  1. 1.Department of Physical Medicine and RehabilitationChang Gung Memorial HospitalChina
  2. 2.Department of PhysiologyNational Yang-Ming UniversityTaipeiTaiwan, ROC
  3. 3.Department of KinesiologyUniversity of TexasAustin
  4. 4.National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUSA
  5. 5.Laboratory of Exercise BiochemistryTaipei Physical Education CollegeTaipeiTaiwan (ROC)