Pharmacological characterization of dopamine receptors in parasympathetic innervation of rat heart.
The action of dopamine agonists (apomorphine, bromocriptine, pergolide and quinpirole) on the bradycardia induced in vivo by electrical stimulation of the vagus nerves was studied in pithed rats pretreated with atenolol. The dopamine agonists decreased significantly the vagal-induced but not the acetylcholine-induced bradycardia. The first effect was blocked by (S)-sulpiride or domperidone but not by yohimbine, prazosin or SCH 23390. Both effects were antagonized by methylatropine. The data suggest the presence of presynaptic and/or ganglionic dopamine DA2 receptors in the parasympathetic innervation of the rat heart, stimulation of which inhibits the release of acetylcholine.
Laboratoire de Pharmacodynamie, U.F.R. de Pharmacie, Université de Bordeaux, France.
J
J
Roquebert
A
A
Moran
P
P
Demichel
M F
MF
Sauvage
D000109:Acetylcholine / Q000502:physiology; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001919:Bradycardia / Q000503:physiopathology; D001971:Bromocriptine / Q000494:pharmacology; D003655:Decerebrate State; D015259:Dopamine Agents / Q000494:pharmacology*; D004558:Electric Stimulation; D004873:Ergolines / Q000494:pharmacology; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D008297:Male; D010479:Pergolide / Q000494:pharmacology; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology
D015259:Dopamine Agents; D004873:Ergolines; D011954:Receptors, Dopamine; D019257:Quinpirole; D010479:Pergolide; D001971:Bromocriptine; D001058:Apomorphine; D000109:Acetylcholine