moreover , mu ligands protected the analgesia evoked by ed50s of morphine , [ d-ala2 , n-me-phe4 , met- ( o ) 5-ol ] enkephalin ( fk 33-824 ) , [ d-ala2 , n-me-phe4 , gly-ol5 ] enkephalin ( dago ) and human beta-endorphin at doses ( ed50s ) lower than those required for delta ligands ( approximately ed90s ) to reach a similar protection . delta preferential ligands effectively protected the analgesia induced by ed50s of [ d-ala2 , d-leu5 ] enkephalin ( dadle ) , [ d-thr2 , leu5 ] enkephalin-thr6 ( dtlet ) and [ d-pen2 , d-pen5 ] enkephalin ( dpdpe ) from the beta-fna-deteriorating effect .
C0014298
enkephalin
C0525856
dpdpe