title: Recent developments in the bioassay of opioids.
mesh_terms: D000818:Animals; D001681:Biological Assay; D001921:Brain / Q000378:metabolism; D004723:Endorphins / Q000032:analysis* / Q000494:pharmacology; D008024:Ligands; D011957:Receptors, Opioid / Q000187:drug effects* / Q000378:metabolism; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu
chemical_list: D004723:Endorphins; D008024:Ligands; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu