the order of agonist competition for the binding site was epinephrine ( ki = 2.3 +/- 0.5 microm ) greater than or equal to norepinephrine ( ki = 4.4 +/- 1.3 microm ) much greater than isoproterenol ( ki = 195.5 +/- 27.6 microm ) , consistent with an alpha-adrenergic interaction .
C0014563
epinephrine
C0028351
norepinephrine