Effects of naturally occurring catecholamines on adrenergic neuro-effector interaction in isolated cutaneous veins
Dalemans, P.; Janssens, W.; Verbeuren, T.; Vanhoutte, P.M.
Archives Internationales de Pharmacodynamie et de Therapie 220(2): 333-334
1976
ISSN/ISBN: 0003-9780 PMID: 182095 Document Number: 99827
Helical strips of dog saphenous veins were incubated in solutions containing 3H-norepinephrine and mounted for superfusion and determination of 3H-norepinephrine and metabolites in the superfusate. In control strips, but not in veins treated with cocaine, norepinephrine caused a slow and moderate increase in the efflux of 3H-norepinephrine and its deaminated metabolites. Epinine and dopamine caused rapid and marked increases in the efflux of 3H-norepinephrine and its deaminated metabolites. The presynaptic .alpha. receptor mediating feedback inhibition of norepinephrine release may have a different affinity for naturally occurring amines than do the postsynaptic receptors causing contraction of the smooth muscle cells.