Brain H-3-catecholamine metabolism in experimental cerebral ischemia

Unilateral ligation of a common carotid artery in gerbils causes a major depletion of brain dopamine, which is most marked in brain regions known to receive dopaminergic projections. To determine whether this depletion reflects release of stored dopamine, a radioactive label (H-3-dopamine) was introduced into brain dopamine pools 4 hours prior to ligation. Twenty-four hours later, brain H-3-catecholamines were profoundly depressed ipsilateral to the lesion among animals exhibiting clinical signs of stroke. Within brain regions known to receive dopaminergic projections, common carotid ligation also was associated with a selective decrease in the concentration of H-3-deaminated metabolites. These data suggest that cerebral ischemia is associated with release of catecholamines, as well as with impaired oxidative metabolism of catecholamines.