title: Effect of naloxone and morphine on guinea pig tonic immobility.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D007103:Immobilization; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009129:Muscle Tonus / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects
chemical_list: D011957:Receptors, Opioid; D009270:Naloxone; D009020:Morphine