EFFECTS OF S14001 ON ADRENERGIC NEUROEFFECTOR INTERACTION IN ISOLATED CANINE SAPHENOUS VEINS

1. The effects of (S) fluoro-6(morpholinyl-2 methoxy)-8-tetrahydro-1,2,3,4 quinoleine (S14001) on adrenergic neurotransmission in isolated canine saphenous veins were investigated in experiments which measured the accumulation, overflow and metabolism of H-3-norepinephrine. 2. S14001 inhibited the accumulation of total tritium (H-3-norepinephrine and H-3-metabolites of norepinephrine) in a concentration-dependent manner. 3. Under basal conditions, S14001 increased tension and basal efflux of total tritium; the latter consisted predominantly of H-3-DOPEG. The increases in these parameters were not inhibited by desmethylimipramine (DMI). 4. During electrical stimulation, S14001 increased the contraction and overflow of total tritium; the latter consisted predominantly of H-3-DOPEG. The increases in these parameters were inhibited by DMI. 5. These experiments suggest that S 14001 has dual effects on adrenergic neurotransmission in the canine saphenous vein: (a) an inhibitory action on the neuronal accumulation; and (b) a pharmacological displacement of the transmitter from adrenergic nerve terminals.