Abstract:

The purpose of this study is to probe into the effects of different hypoxia training methods on skeleton muscle HIF1αmRNA in rats, in order to provide theoretical and applying basis for the application of hypoxia training to sports training. 90 rats are selected from 120 male SD rats (6 weeks old) by three weeks adaptable training and exhaustive test . These rats were randomly divided into 9 groups: normoxia quiet control group（C）, continuing hypoxia group(CH), intermittent hypoxia group(IH), normaxia training group(T), livinghigh and traininghigh group(HiHi), livinghigh and traininglow group(HiLo), livinglow and traininghigh group(LoHi), normoxia training group after HiHi and normoxia training group after HiLo. During the 6 weeks of experimental period, we employed the 13.6% concentration of oxygen (equal to altitude of 3?500?m) in the hypoxic chamber. The rats of hypoxia training were introduced to treadmill. The training speed was 30?m/min in hypoxia and 35?m/min in normoxia. The rats were trained 5?d/week and were sacrificed after 6 weeks. Technology of RQPCR, immunohistochemistry andWestern blot are adopted in order to test the mRNA and protein level changes of  HIF1αin rats′ skeletal muscle to probe further into the mechanisms of the acclimatization in skeletal muscle. It is found that the mRNA level of HIF1α in rat skeletal muscle increased significantly (P＜0.05) in HiHi and HiLo comparing with LoLo; and the mRNA level of HIF1α (1.05 times) in rat skeletal muscle increased significantly (P＜0.01) in HiHi comparing with C group. Comparing with LoLo group, the mRNA level of HiHi and HiLo increased significantly. The mRNA level of HIF1α declined significantly in T group after HiHi and HiLo(P<0.05). The results show that the mRNA level of HIF1α in rat skeletal muscle increased significantly in HiHi, HiLo and CH. Moreover,the level of HIF1α is closely related to the extend of hypoxia and the exposure time.

Key words:  hypoxia training; 　HIF1α; gene expression; skeletal muscle