title: Met-enkephalin attenuates morphine tolerance in rats.
mesh_terms: D000698:Analgesia; D000818:Animals; D004347:Drug Interactions; D004361:Drug Tolerance; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects
chemical_list: D004723:Endorphins; D004745:Enkephalins; D009020:Morphine