three opioid agonists ( [ d-ala2 , n-mephe4 , gly-ol5 ] enkephalin ( dago ) , [ d-pen2 , d-pen5 ] enkephalin ( dpdpe ) and u50488h ) were tested independently for their ability to produce analgesia in the formalin test .
C0014298
enkephalin
C0525773
dago