aq-a39 ( 5,6-dimethoxy-2- [ 3- [ ( 3,4-dimethoxy ) phenylethyl ) methylamino ] propyl ) - phthalimidine ) , a specific bradycardic agent , and verapamil , a calcium channel blocker , were studied for their ability to alter rate and force of contraction in the presence and absence of isoproterenol , a beta-adrenergic stimulant , using isolated guinea pig atria .
C0428977
bradycardic
C0022245
isoproterenol