Piribedil-induced anti-hypoxic protection in rats

The action of the dopaminergic agonist, piribedil, on a conditioned avoidance response was studied in normoxic or hypobaric hypoxic rats. This agonist has no effects in normoxia, but induced an anti-hypoxic protection (improvement of learning in hypoxia), antagonised by low doses of pimozide. The mechanism of the anti-hypoxic property seems to be mediated by the stimulation of the postsynaptic dopaminergic receptors, but does not exclude the role of noradrenergic pathways, as shown by the stabilisation of norepinephrine levels during hypoxia after treatment with piribedil.