Evidence for catecholamine involvement in the suppression of locomotor activity due to hypoxia

Abstract

Locomotor activity of mice under 12 or 21% oxygen in nitrogen was measured. Under 12% oxygen there was a decrease in locomotor activity which was not reversed by administration of amphetamine; however, administration of a sub-threshold dose of l-dopa in combination with a peripheral decarboxylase inhibitor before the amphetamine restored the locomotor stimulant action of the drug under hypoxia. In contrast to amphetamine, the increase in locomotor activity after the administration of a combination of noradrenaline and dopamine receptor stimulating agents, Clonidine plus apomorphine respectively, was not inhibited by hypoxic conditions. Data suggest an involvement of central catecholamine neurotransmission in the disruption of locomotor activity due to hypoxia.