in competition studies , alpha-adrenergic antagonists and agonists inhibited the binding of 125i-rau-papc with a potency order consistent with an interaction at alpha 2-adrenergic receptors ( rauwolscine greater than phentolamine greater than prazosin ; clonidine greater than ( - ) -epinephrine greater than ( - ) -norepinephrine greater than dopamine greater than ( + ) -epinephrine ) .
C0028351
norepinephrine
C0014563
epinephrine