title: Enhanced analgesic effects of morphine after chronic administration of naloxone in the rat.
mesh_terms: D000700:Analgesics; D000818:Animals; D004357:Drug Synergism; D005260:Female; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects; D013997:Time Factors; D014828:Vocalization, Animal / Q000187:drug effects
chemical_list: D000700:Analgesics; D011957:Receptors, Opioid; D009270:Naloxone; D009020:Morphine