Effect of dopamine on the cyclic adenosine monophosphate generating system in the rabbit internal carotid and middle cerebral artery.
The effect of in vitro addition of dopamine on the 3'-5'-cyclic adenosine monophosphate (cAMP) generating system of rabbit internal carotid and middle cerebral artery was studied. Dopamine increased cAMP levels in a dose-dependent manner in both arteries. The DA1-receptor antagonist SCH 23390 decreased the dopamine-elicited cAMP increase. On the contrary, the DA2-receptor antagonist L-sulpiride caused an increase in dopamine-dependent cAMP levels. The simultaneous addition of SCH 23390 and of L-sulpiride abolished any effect of dopamine on cAMP content. The DA2-receptor agonists bromocriptine and co-dergocrine decreased cAMP levels. The above findings indicate the existence in the rabbit internal carotid and middle cerebral artery of 2 types of dopamine receptors mediating respectively, the increase (DA1-effect) and the decrease (DA2-effect) of cAMP levels.
Amenta
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Dipartimento di Scienze Neurologiche, Università La Sapienza, Roma, Italy.
Cavallotti
C
C
Collier
W L
WL
De Rossi
M
M
Ricci
A
A
Amenta
F
F
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D002339:Carotid Arteries / Q000187:drug effects / Q000378:metabolism; D002536:Cerebral Arteries / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis*; D004298:Dopamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D011817:Rabbits; D011954:Receptors, Dopamine / Q000187:drug effects; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D011954:Receptors, Dopamine; D013469:Sulpiride; D000242:Cyclic AMP; D004298:Dopamine