慢性低氧及跑台训练对大鼠骨骼肌成肌调节因子MyoD和myogenin基因表达的影响

The Influences of Chronic Hypoxia and Exercise Training on the Gene Expression of MyoD and Myogenin of Skeletal Muscle of Rats

旨在研究慢性低氧及跑台训练对大鼠骨骼肌成肌调节因子MyoD和myogenin基因表达的影响,对揭示肌肉收缩蛋白性能的变化机制具有特定的意义。方法:取健康SD雄性大鼠28只,随机分成4组:1)慢性对照组(C),2)常氧训练组(NT),3)低氧安静组(HC),4)低氧居住常氧训练组(HT)。其中HC、HT两个低氧组每天保证22 h生活在模拟4 000 m高原的低氧舱(氧浓度12.7%),经2 d跑台适应后,NT、HT两个训练组每天进行常氧跑台上坡训练1 h,28 d后,测定骨骼肌成肌调节因子MyoD和myogenin的mRNA基因表达。结果:与常氧对照组(C)相比,低氧和训练各组的骨骼肌成肌调节因子MyoD和myogenin基因表达均明显升高(P<0.01),其中慢性低氧组(HC)两种因子升高幅度最大;但低氧暴露加常氧训练后(HT),安静状态下成肌调节因子的基因表达并不进一步升高,其机理有待进一步研究。

The propose of this article is to investigate the influences of chronic hypoxia and exercise training on the gene expression of MyoD and myogenin of skeletal muscle in rat. 28 male SD rats were randomly divided to four groups： （1） Control at normoxic condition（C）, （2） Training at normoxic condition（NT）, （3） Control at hypoxic condition（nC） , （4）Living at hypoxic condition and Training at normoxic condition （HT）. After 28 day, the gene expression of quadriceps MyoD and myogenin mRNA is determined by RT-PCR technology. The effects shows that the mRNA contents of MyoD and myogenin in HC, HT and NT groups are all upregulated by hypoxia or exercise training compared with that in C group（P〈 0. 01）, and the highest value was that of the HC group. Thus chronic hypoxia induced the significant increases of MyoD and myogenin mRNA contents, and the exercise training also did. But hypoxia and training （HT） didn＇t induce a higher val- ue. The mechanism of the changes of MyoD and myogenin will be probed in future experiments.