| Summary: | 碩士 === 臺北巿立體育學院 === 運動科學研究所 === 93 === The present study was to investigate the effects of eight weeks intermittent hypoxia (14% O2) on glucose tolerance and skeletal muscle morphology. Twenty-one Sprague-Dawley rats were matched for weight and assigned into following 3 treatments: control (C), 1-hr hypoxia/day (O), and 8-hr hypoxia/day (E). The fiber types of soleus and plantaris muscle were determined using the mATPase(pH4.6) and SDH method, and capillary density was visualized using the AP method. Abdominal fat weight, Fasting blood glucose, fasting and postprandial serum insulin concentration in E group was significant lower than C group during the OGTT. The E group had a significantly increased percentage of Type IIa fiber and capillary density in soleus muscle than C group, whereas the fiber size of soleus muscle decreased. Significant correlations were found among fasting blood glucose(r=0.43, p<.05), postprandial serum insulin concentration(r=0.50, p<.05), and abdominal fat weight. Furthermore, the fiber size of soleus muscle correlated significantly with postprandial serum insulin concentration(r=-0.43, p<.05). There were no significant correlations between fiber type transformation and capillary density. In conclusion, intermittent hypoxia improved fasting blood glucose and insulin sensitivity. The level of the improvement could be associated with the effect of hypoxia duration on body weight, visceral fat weight, and muscle fiber size.
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