Chronic exposure to simulated altitude does not increase angiogenic activity in skeletal muscle of rats

In order to examine whether the hypoxia of high altitude increases angiogenic activity in skeletal muscle, six male Wistar rats were subjected to a simulated altitude of about 5,500 m (ambient pressure 380 mmHg) for 3 weeks, and the whole soleus, gastrocnemius, and extensor digitorum longus muscles were collected. As a result, any muscle extracts from high altitude rats did not significantly enhance the capillary growth in an in vitro angiogenesis model compared with those from sea-level rats. This appeared to confirm previous morphological studies that hypobaric-hypoxic environment did not cause the formation of new capillaries in skeletal muscles.