nitric oxide tanks! hmmmmmmmmmm
Nitric Oxide Helps Humans Adapt to High Altitudes
NEW YORK (Reuters Health) - People living at extremely high altitudes
produce higher concentrations of a compound that facilitates oxygen
flow throughout the body, researchers report.
The compound, nitric oxide (NO), is produced in the lungs and helps
blood vessels to dilate, thereby allowing oxygen-carrying blood to
flow more freely. ****NO also boosts the oxygen-carrying capacity of
hemoglobin, a component of red blood cells.*****
The findings, which are based on information from people in Bolivia
and Tibet, shed light on how humans adapt to high altitudes, according
to Dr. Cynthia M. Beall from Case Western Reserve University in
Cleveland, Ohio, and colleagues.
``The similar responses of these two geographically separate
high-altitude populations underlines the importance of NO for life
under hypoxic stress,'' they write.
Hypoxia is a severe lack of oxygen that causes symptoms ranging from
mental confusion to a life-threatening swelling of the brain.
According to the findings in the November 22 issue of Nature, people
who live at very high altitudes adapt by producing more NO than
individuals living at sea level. The researchers measured
concentrations of NO exhaled by 105 healthy nonsmokers living in Tibet
at 4,200 meters above sea level, in 144 people living in Bolivia at
3,900 meters above sea level, and in 33 people living at sea level in
the US.
The Tibetans were found to have more than twice the concentration of
NO that US citizens had. Similarly, the concentration of NO exhaled by
the Bolivians was 25% greater than concentrations exhaled by US
individuals.
``The functional advantage of high NO concentrations in the lungs
seems to be to offset ambient hypoxia by enhancing the uptake of
oxygen from the lungs, which presumably improves delivery of oxygen to
peripheral tissues,'' Beall and colleagues conclude.