从生长激素-胰岛素样生长因子Ⅰ变化观察两种模拟高原训练过程对大鼠身体成分的影响

Influence of two hypoxia-training ways on rat body composition by the changes in growth hormone-insulin-like growth factor Ⅰ levels

目的：从生长激素胰岛素样生长因子Ⅰ变化的角度观察高住低练和低住高练两种模拟高原训练过程对身体成分的影响。方法：实验于2005-03／05在广州体育学院运动生化省重点实验室进行。①实验材料及分组：雄性SD大鼠30只，体质量180～220g，随机分为低住低练对照组、高住低练组和低住高练组，每组10只。②实验过程：模拟高原低氧环境为海拔2500m（15．4％O2），高住为每天12h，低住低练组和高住低练组运动强度为25m／min，低住高练组20m／min运动1h／d，运动6d／周。③评估：4周后测试血清生长激素、胰岛素样生长因子Ⅰ、肝脏、腓肠肌胰岛素样生长因子Ⅰ和身体成分。结果：①低住高练组血清生长激素、骨骼肌胰岛素样生长因子Ⅰ高于高住低练组（P〉0．05）；肝脏中胰岛素样生长因子Ⅰ含量高于高住低练组（P〈0．05）；血清胰岛素样生长因子Ⅰ低于高住低练组（P〈0．05）。②低住高练组大鼠体质量、腓肠肌质量高于高住低练组（P〈0．05）；脂肪质量、脂肪比重、腓肠肌比重各组间差异不显著（P〉0．05）。结论：低住高练模式更有利于机体保持稳定的体质量和代谢平衡。

AIM： To investigate the effects of living high-training low and living low-training high in plateau on body composition by the changes in the content of growth hormone-insulin-like growth factor Ⅰ（IGF-Ⅰ）. METHODS： Experiments were performed at the Laboratory of Sports and Biochemistry of Guangzhou Sports College from March to May 2005. （1）Thirty male Sprague-Drawly （SD） rats （180 220 g） were randomly divided into living low-training low （Lo-Lo）, living high-training low （Hi-Lo）, living low-training high （Lo-Hi） groups with 10 in each group. （2）In the hypoxic environment, the oxygen content was 15.4% （simulated altitude of 2 500 m）. The Hi-Lo group lived in the hypoxic environment for 12 hours. The rats were trained on a treadmill using a progressive protocol that plateaued at 25 m/min in normal environment and at 20 m/min in hypoxic environment for 1 hour every day, 6 days per week for a total of four weeks. （3）Serum growth hormone, IGF-Ⅰ, liver, gastrocnemius IGF-Ⅰ and body composition were measured. RESULTS： （1）The serum growth hormone and the muscle IGF-Ⅰ contents of the Lo-Hi group were higher than the Hi-Lo group （ P 〉 0.05 ） . Liver IGF-Ⅰ content in the Lo-Hi group was significantly higher than the Hi-Lo group （P 〈 0.05 ） . The serum IGF-Ⅰ content was lower than the Hi-Lo group （P 〈 0.05 ）.（2）Compared to the Hi-Lo group, the weight and gastrocnemius muscle mass of Lo-Hi group were higher （P 〈 0.05） . The gastrocnemius muscle proportion, fat weight and fat proportion had no great differences in each group （P 〉 0.05） . CONCLUSION： The way of Lo-Hi was better in keeping the balance of weight and metabolism.