the types of binding sites were discriminated on the basis of their affinities for [ 3h-d-ala2-mephe4-gly5-ol ] enkephalin ( [ 3h ] dago ) , [ 3h-d-ala2-d-leu5 ] enkephalin , and [ 3h ] ethylketocyclazocine and the relative potencies of the displacing ligands , dago , [ d-ser2-leu5 ] enkephalyl-thr and trans-3,4-dichloro-n-methyl-n- [ 2- ( 1-pyrrolidinyl ) - cyclohexyl ] benzeneacetamide methanesulfonate hydrate ( u50488h ) , which are selective for mu , delta and kappa type binding sites respectively .
C0014298
enkephalin
C0525773
dago