administration in the dr of a selective mu opioid receptor agonist , ( d-ala2 , n-me-phe4 , gly5-ol ) -enkephalin ( dago ) , in doses ranging from 0.01 to 1 microgram/0.5 microliter , dose-dependently reduced aggression caused by apomorphine 20 mg/kg intraperitoneally .
C0014298
enkephalin
C0525773
dago