Nitric Oxide Key to Living at High Altitudes
CLEVELAND—How can some people live at high altitudes and thrive while others struggle to obtain enough oxygen to function?
The answer for Tibetans who live at altitudes around 14,000 feet is increased nitric oxide (NO) levels. High levels of NO circulate in various forms in the blood and produce the physiological mechanisms that cause the increased blood flow that maintains oxygen delivery despite hypoxia—low levels of oxygen in the ambient air and the bloodstream. Researchers from Case Western Reserve University and the Cleveland Clinic report that Tibetans have 10 times more NO and have more than double the forearm blood flow of low-altitude dwellers. The findings from a comparison of NO levels in the high and low altitude dwellers are reported in the article, “Higher Blood Flow and Circulating NO Products Offset High-altitude Hypoxia among Tibetans,” in the current Proceedings of the National Academy of Sciences (PNAS).
