title: Recent developments in bioassay using selective ligands and selective in vitro preparations.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D001681:Biological Assay / Q000379:methods*; D007082:Ileum / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D008297:Male; D009294:Narcotics / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D017450:Receptors, Opioid, mu; D014649:Vas Deferens / Q000378:metabolism
chemical_list: D008024:Ligands; D009294:Narcotics; D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu