Cardiovascular pharmacology of ASL-7022, a novel catecholamine. I. Inotropic, chronotropic and pressor actions.

ASL-7022 (2-[3-(3,4-dihydroxy-phenyl)-1-methylethyl]-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene) was examined for inotropic, chronotropic and blood pressure activity in pentobarbital anesthetized, vagotomized dogs instrumented for measurement of right ventricular contractile force, blood pressure and heart rate. The compound produced a dose-dependent increases in contractile force accompanied by bradycardia and hypotension. At high doses, the compound increased heart rate. At doses which increased contractile force by 100%, ASL-7022 produced no significant increase in heart rate, whereas dopamine and dobutamine produced small but significant increase in cardiac rate, ASL-7022 was therefore found to be more inotropic selective with respect to cardiac action than dopamine or dobutamine. Beta blockade reduced the positive inotropic, positive chronotropic and depressor action of the compound and also eliminated the negative chronotropic effect. ASL-7022 appears to be a beta adrenergic receptor agonist which possesses a unique spectrum of cardiovascular action.