title: Dimeric tetrapeptide enkephalins display extraordinary selectivity for the delta opiate receptor.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002460:Cell Line; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000138:chemical synthesis / Q000378:metabolism*; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D004723:Endorphins; D004745:Enkephalins; D011957:Receptors, Opioid