intracerebroventricular administration of the selective mu ( mu ) opioid receptor agonist , ( d-ala2 , n-mephe4 , gly-ol5 ) enkephalin ( dago ; 25-50 micrograms ) , or the selective delta ( delta ) opioid agonist , [ d-pen2 , d-pen5 ] enkephalin ( dpdpe ; 3-50 micrograms ) , like morphine , produced significant decreases in hepatic glutathione 3 h after administration .
C0014298
enkephalin
C0525773
dago