Inhibitory effects of hypoxia on dopamine release.

Behavioral and neurochemical results refer to an impairment of the dopaminergic system produced by hypoxia. On that account we determined the chemically (K+, amphetamine) and electrically stimulated release of dopamine from rat striatum slices which were preloaded with labeled dopamine following the animals' exposure to hypobaric hypoxia. The effect of hypoxia consists in a marked inhibition of dopamine release depending both on the degree of hypoxia and on the kind of stimuli used. Dopamine release inhibition reflects not only the direct effect of hypoxia, which seems to be connected especially with the vesicular compartment, but also adaption and restitution processes. Regarding the effects on rats at the age of two weeks the resistance of young animals against hypoxia may be founded also upon missing vesicular mechanisms of distinct vulnerability.