title: Structure-activity relationships of opioid peptides.
mesh_terms: D000818:Animals; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006168:Guinea Pigs; D009130:Muscle, Smooth / Q000187:drug effects; D011957:Receptors, Opioid / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D004723:Endorphins; D004745:Enkephalins; D011957:Receptors, Opioid