opioid binding was measured by using [ 3h ] u69 593 , [ 3h ] ( 2-d-penicillamine,5-d-penicillamine ) enkephalin ( [ 3h ] dpdpe ) or [ 3h ] [ d-ala2 , mephe4 , gly- ( ol ) 5 ] enkephalin ( [ 3h ] dago ) as selective radioligands for k , delta and mu opioid receptors , respectively .
C0525856
dpdpe
C0014298
enkephalin