Pre-junctional regulation of sympathetic neurotransmission in the mouse vas deferens: assessment of agonist and antagonist potencies.
Dopaminergic agonists and antagonists were tested on the field-stimulated mouse vas deferens. Both LY 171555 and SK & F 38393, relatively selective DA2 and DA1 receptor agonists, respectively, produced concentration-dependent inhibition of the field stimulation-induced contractions, without modifying the baseline tone nor the contractile responses to the exogenous noradrenaline. Both LY 171555 and SK & F 38393 concentration-response curves were shifted rightward in a parallel manner by sulpiride (relatively specific DA2 antagonist) and SCH 23390 (relatively specific DA1 antagonist), respectively. The results are suggestive of the existence of pre-junctional dopamine receptors involved in the regulation of sympathetic neurotransmission in rodent vasa.
Carratù
M R
MR
Institute of Pharmacology, Medical Faculty, University of Bari, Italy.
Camerino
D C
DC
De Serio
A
A
Ferrari
E
E
Mitolo-Chieppa
D
D
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D015259:Dopamine Agents / Q000494:pharmacology; D004873:Ergolines / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000294:innervation; D009638:Norepinephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D019257:Quinpirole; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects; D014649:Vas Deferens / Q000294:innervation*
D001552:Benzazepines; D015259:Dopamine Agents; D004873:Ergolines; D019257:Quinpirole; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D011433:Propranolol; D009638:Norepinephrine