Can the amrinone struggle against myocardial depression induced by propanolol in narcotized dog

In the anesthetic dog, it has been researched if the amrinone, new positive inotropic agent, was able to face or to correct the depressor effect induced by propranolol. Used by simultanous perfusion to propranolol at the dose of 100 ug. Kg[-1], the amrinone increases significantly the LD 100 of propranolol from 33.4 +/- 2 mg. Kg[-1] to 44.14 +/- 4.21 mg. Kg[-1] and to 53.9 +/- 12.2 mg Kg[-1] at the dose of 300 ug. Kg[-1]. After the systolic arterial pressure reduction of 50 to 60% by the propranolol, perfusion of 25 or 50 ug. kg of amrinone correct quickly and completely the tensional decrease. The amrinone seems as a therapeutics not without interest in case of cardiovascular collapse induced by adrenergie betablocking agent