Alterations in norepinephrine and dopamine content in selected brain areas of guinea pigs adapted to simulated high altitude.

The alterations in brain content of norepinephrine (NE) and dopamine (DA) were studied in guinea pigs adapted to simulated high altitude (hypobaric hypoxia) equivalent to 5500 meters. The animals were adapted for 46 days over a period of 82 days to a pressure of 375 mm Hg. The animals were then killed and the following brain parts dissected: cerebellum, neocortex, caudate head/basal forebrain, diencephalon/rhinencephalon, and brain stem. NE and DA content were analyzed by high pressure liquid chromatography with electrochemical detection by a technique described. Results showed a significant increase of NE and DA in neocortex; a significant increase of DA but not NE in caudate/basal forebrain, and a significant decrease of NE and not DA in diencephalon/rhinencephalon.