ISSN:
1432-2013
Keywords:
Hypobarie
;
Hypoxia
;
Norepinephrine turnover
;
Dopamine turnover
;
Central nervous system
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The elimination rate constant, half-life and turnover time of dopamine (DA) and norepinephrine (NE) were determined, after inhibiting their biosynthesis by α-methyl-para-tyrosine (αMT), in the hypothalamus, striatum and the remainder of the brain of rats exposed to different degrees of hypobaric hypoxia, corresponding to altitudes of 1,800, 3,800, 5,200 and 7,000 meters. The effects varied as a function of the degree of hypoxia and the brain region studied. The turnover time of NE in the hypothalamus remained unchanged, regardless of the altitude, while in the rest of the brain the rate constant of neurotransmitter elimination decreased inversely as a linear function of the degree of hypoxia. On the contrary, the changes of the DA turnover time in the striatum and the rest of the brain, were biphasic, being accelerated by moderate altitudes (1,800 m) and retarded by the two highest simulated altitudes studied as a function of hypoxia. The differential effects of hypoxia on NE and DA turnovers are attributed to different sensitivities of the respective enzyme systems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00582147
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