[Changes in catecholamines of the striatum during 5% oxygen administration and the alleviating effects of flunarizine...

Five percent oxygen was administered to rats under controlled respiration. The concentrations of catecholamines and their metabolites (dopamine, HVA, DOPAC, norepinephrine) were measured during 5% oxygen administration and subsequent recovery period. Flunarizine, a calcium channel blocker, was administered and its effects on catecholamine fluctuations were studied. Results were as follows. Dopamine increased with 5% oxygen administration. DOPAC and norepinephrine decreased and no changes were seen in HVA. After 20 min of hypoxia, catecholamine contents returned to the control levels in another 2 hours of air breathing. When flunarizine was administered in advance, changes in catecholamine content appeared to be lower during 5% oxygen administration and subsequent recovery period.