in a comparison of potencies against [ 3h ] - [ d-ala2 , d-leu5 ] enkephalin ( 3h-dadle ) and [ 3h ] - [ d-ala2 , mephe4 , gly-ol5 ] enkephalin ( 3h-dago ) as delta and mu tracers , respectively , enkephalin dimer showed a very high affinity , especially for the delta opiate receptors .
C0525773
dago
C0014298
enkephalin