Coronary vascular activity of the novel inotropic pro-drug ibopamine and the de-esterified active form epinine.
The effects of the novel inotropic pro-drug, ibopamine, and the de-esterified active form, epinine (N-methyldopamine), were investigated in isolated canine circumflex coronary arteries in vitro. Both ibopamine and epinine produced concentration-dependent contractions of isolated canine coronary arteries, with epinine being approximately 7-fold more potent than ibopamine. The coronary vasoconstrictor response produced by ibopamine was inhibited completely by the irreversible alpha-adrenoceptor antagonist, phenoxybenzamine, whereas the response produced by epinine was transformed into relaxation which was inhibited by the beta-adrenoceptor antagonist, propranolol. The results indicate that ibopamine has the capacity to produce coronary arterial vasoconstriction, but that this activity may be partially offset by the beta-adrenoceptor-mediated activity of the active form, epinine.
Ohlstein
E H
EH
Department of Pharmacology, Smith Kline & French Laboratories, King of Prussia, PA.
Kopia
G A
GA
Ruffolo
R R
RR
D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects*; D003846:Deoxyepinephrine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015237:Dinoprost / Q000494:pharmacology; D004285:Dogs; D004298:Dopamine / Q000031:analogs & derivatives*; D066298:In Vitro Techniques; D011355:Prodrugs / Q000494:pharmacology
D002316:Cardiotonic Agents; D011355:Prodrugs; C023487:ibopamine; D015237:Dinoprost; D003846:Deoxyepinephrine; D004298:Dopamine