the selectivities of morphine , codeine , l-methadone and d-propoxyphene , towards the binding sites in mouse brain membranes labelled by 3h-dihydromorphine ( dhm ) , 3h-ethylketocyclazocine ( ekc ) and 3h-d-ala2-leu5-enkephalin ( dale ) , were investigated .
C0026549
morphine
C0009214
codeine