dermorphin and the selective mu-receptor ligand ( d-ala2 , mephe4 , gly5-ol ) -enkephalin ( dago ) had similar high potencies in competing with ( 3h ) -dermorphin binding , whereas the inverse holds for the prototypical delta receptor ligand ( d-pen2 , d-pen5 ) -enkephalin ( dpdpe ) , which exhibited a potency three orders of magnitude lower .
C0525773
dago
C0014298
enkephalin