Changes in microRNAs during hypoxia-induced physiological adaptation

在运动过程中，活动肌肉的氧张力福尔斯下降到静息值的1/10。这种低氧刺激促进了低氧诱导因子（HIF-1 α）的积累，并引起骨骼肌的各种适应性变化。这项研究旨在研究microRNA如何对急性和/或慢性运动做出反应。本研究结果表明，运动训练抑制表达的抗血管生成的microRNA，从而促进毛细血管的生长，在年轻的大鼠。然而，在老年大鼠中，运动训练上调了抗血管生成和促血管生成的microRNA，从而运动诱导的毛细血管生长可能会受到轻微抑制。

During exercise, oxygen tension in the active muscle falls to 1/10 of resting value. This hypoxic stimulus facilitates an accumulation of hypoxia-inducible factor (HIF-1alpha), and causes various adaptive changes in skeletal muscle. This study was designed to examine how microRNAs react to acute and/or chronic exercise. The present results suggest that exercise training suppresses expression of anti-angiogenic microRNAs, thus facilitate capillary growth, in young rats. However, in aged-rats, exercise training upregulates both anti- and pro-angiogenic microRNAs, thereby exercise-induced capillary growth may be slightly suppressed.