Interaction of bradykinin with dopaminergic receptors in the CNS

The influence of bradykinin on the action of compounds affecting predominantly the dopaminergic receptor was studied in behavioral tests (Lat test and sterotypy) and biochemically (estimation of the level of biogenic amines--noradrenaline, dopamine and serotonin, and their metabolites--normetanephrine, homovanillic and 5-hydroxyindoleacetic acids in the brain tissue). Bradykinin potentiated the action of nialamide with L-dopa, dopamine, 1,3-dimethyl-5-aminoadamantane, apomorphine and noradrenaline. Spiroperidol abolished potentializing effect of bradykinin on the central action of nialamide with L-DOPA and of noradrenaline. In animals receiving spiroperidol with bradykinin psychostimulatory action of noradrenaline was also not observed. FLA-63--inhibitor of dopamine beta-hydroxylase--increased the potentializing effect of bradykinin on the central action of dopamine. Most significant biochemical changes between the group receiving nialamide alone and the group given nialamide together with bradykinin have been observed in corpus striatum, where the level of dopamine and its metabolite--homovanillic acid--increased. The results obtained point out that the potentiation of the central effects of catecholamines by kinins depends mainly on the interaction of this peptide with dopaminergic receptor.