Hypotensive action and alpha-adrenolytic properties of a new dopaminergic agonist, CU 32-085, in the rat.
The effect of an 8-alpha-amino-ergoline-derivative, CU 32-085, recently characterized as a dopamine agonist, was studied on blood pressure and heart rate in normotensive anesthetized rats. The effects of CU 32-085 and bromocriptine on dose-response curves to sympathomimetic agents (adrenaline, noradrenaline, methoxamine and clonidine), intravenously administered, were also studied. CU 32-085 slowed heart rate and lowered blood pressure. The hypotensive effect was antagonized by pretreatment with sulpiride. CU 32-085 and bromocriptine reduced the pressor effect of adrenaline, noradrenaline and methoxamine and the hypotensive action of clonidine. These results suggest that the hypotensive action of CU 32-085, like bromocriptine, is mainly due to an action on dopaminergic receptors. In addition, the data obtained with sympathomimetic agents suggest that CU 32-085 is a compound with mixed alpha 1 and alpha 2 antagonist properties, similar to bromocriptine.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000758:Anesthesia; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D000978:Antiparkinson Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D001971:Bromocriptine / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology; D004873:Ergolines / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D008729:Methoxamine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*
D000317:Adrenergic alpha-Antagonists; D000959:Antihypertensive Agents; D000978:Antiparkinson Agents; D004873:Ergolines; D011954:Receptors, Dopamine; D001971:Bromocriptine; D008729:Methoxamine; D003000:Clonidine; C031649:mesulergine; D009638:Norepinephrine; D004837:Epinephrine