PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 2577268-5 1989 The metENK actions appear mediated via a mu-opiate receptor; morphine and D-ala-metENK-amide (DALA), a stable analog of metENK, are agonists. Morphine 61-69 proopiomelanocortin Homo sapiens 4-10