低氧训练大鼠骨骼肌组织低氧诱导因子1对血管新生的影响

Effects of hypoxia inducible factor 1 on angiogenesis in skeletal muscle tissues of rats receiving hypoxia training

背景:低氧诱导因子1是一种在氧平衡调节中起关键作用的转录因子,与机体的耐缺氧能力密切相关。目的:观察低氧训练大鼠骨骼肌组织中低氧诱导因子1和血管内皮CD34的蛋白表达,探讨低氧诱导因子1在促进骨骼肌组织血管形成中的作用。方法:将健康雄性SD大鼠60只,随机分为6组:常氧对照组、低氧不运动组、常氧训练组、低住高练组、高住低练组和高住高练低练组。运动组采用10周递增负荷跑台运动训练,每周训练6d,运动量由第1周的速度为15m/min、持续时间为25min递增至第10周速度为28m/min、持续时间为50min,低练组每周二、四、六在相当于海拔1500m的低氧环境中训练,并且在低氧环境中居住,低氧程度由第1周相当于海拔1800m递增至第10周相当于海拔3600m。结果与结论:低氧状态下,低氧诱导因子1有大量的蛋白表达,低氧复合运动表达更多,而CD34蛋白表达只发生在常氧运动组和低氧训练组。提示低氧诱导因子1是促进骨骼肌组织血管新生的一种重要因子,但须结合运动才能产生积极的作用。

BACKGROUND： Hypoxia inducible factor 1 is a kind of transcription factor which plays a crucial role in the organism’s adaptation to changing oxygen tensions. It is closely related to the organism resistance to anoxia. OBJECTIVE： To detect the expression of hypoxia inducible factor 1 and vascular endothelial CD34 protein expression in skeletal muscle tissues of rats receiving hypoxic training; to explore the effects of hypoxia inducible factor 1 on angiogenesis in skeletal muscle tissues. METHODS： A total of 60 healthy male SD rats were randomly divided into six groups： normoxic control group, hypoxic sedentary group, normoxic training group, hypoxic residence plus hyperoxic training group, hyperoxic residence plus hypoxic training group and hyperoxic residence plus hyperoxic/hypoxic training group. Rats in training group were trained with increasing load treadmill exercise 6 days a week for 10 weeks. The exercise volume changed from 15 m/min for 25 minutes in the 1st week to 28 m/min for 50 minutes in the 10th week. Rats in hypoxic groups were trained every Tuesday, Thursday and Saturday under the hypoxia environment equivalent to 1 500 meters above sea level; and lived in low oxygen environments, whose hypoxic degree increased from that equivalent to 1 800 meters in the 1st week to that equivalent to 3 600 meters above sea level in the 10th week. RESULTS AND CONCLUSION： Under the low oxygen condition, hypoxia inducible factor 1 had massive protein expression. The expression was more under the low oxygen environment combined with training. While CD34 protein expression was only detected in normoxic training group and hypoxic trainging group. It indicates that hypoxia inducible factor 1 is an important factor in the promotion of angiogenesis in skeletal muscle tissues, but it can produce positive effects only when combined with exercise.