the ability of codeine-epoxide to displace [ 3h ] dihydromorphine binding was the most effective among three labeled ligands , that is , [ 3h ] dihydromorphine , [ 3h ] -d-ala2-d-leu5-enkephalin and [ 3h ] ethylketocyclazocine , suggesting that codeine-epoxide had a selectively high affinity to mu-receptors , despite the fact the affinities of codeine-epoxide to opiate receptors were slightly less potent than its parent compound , codeine .
C0066908
mu-receptors
C0034801
opiate receptors