the effects of the mu-selective opioid peptide [ d-ala2 , nme-phe4 , met ( o ) 5ol ] enkephalin ( fk 33-824 ) and the delta-selective peptide [ d-pen2 , d-pen5 ] enkephalin ( dpdpe ) were qualitatively and quantitatively similar .
C0014298
enkephalin
C0525856
dpdpe