the mu-selective agonist [ d-ala2 , n-methyl-phe4 , gly5-ol ] enkephalin ( dago ) , the delta-selective agonist [ d-pen2 , d-pen5 ] enkephalin ( dpdpe ) and the reference mu-acting agonist morphine , all produced antinociception after either i.c.v . or intrathecal ( ly ) ( i.t . ) administration .
C0525773
dago
C0014298
enkephalin