catecholamines act with the order of potencies isoproterenol ( ed50 = 50 nmol 1 ( -1 ) greater than epinephrine ( ed50 = 0.1 mumol 1 ( -1 ] greater than norepinephrine ( ed50 = 5 mumol 1 ( -1 ] .
C0007412
catecholamines
C0028351
norepinephrine