title: An update on opioid receptors.
mesh_terms: D000700:Analgesics; D000818:Animals; D004285:Dogs; D004723:Endorphins; D006168:Guinea Pigs; D006801:Humans; D051379:Mice; D011817:Rabbits; D051381:Rats; D011957:Receptors, Opioid / Q000032:analysis / Q000502:physiology*; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D017480:Receptors, sigma
chemical_list: D000700:Analgesics; D004723:Endorphins; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D017480:Receptors, sigma