in the guinea-pig ileum , pretreatment with beta-fna ( 3 x 10 ( -8 ) - 3 x 10 ( -6 ) m ) produced a concentration-dependent antagonism of the inhibitory effect produced by the mu-opioid receptor agonist [ d-ala2 , mephe4 , gly ( ol ) 5 ] enkephalin ( dago ) .
C0014298
enkephalin
C0525773
dago