isoproterenol , epinephrine , and norepinephrine each stimulated the secretion of 35so4-labeled macromolecules from these cultured serous cells with a rank order of potency ( isoproterenol greater than epinephrine greater than norepinephrine ) consistent with the presence of beta 2-adrenergic receptors .
C0014563
epinephrine
C0028351
norepinephrine