title: Antagonism of stress-induced analgesia by quaternary naloxone.
abstract: Both naloxone hydrochloride and the quaternary compound, naloxone methylbromide, significantly reduced antinociception elicited by 90 s of continuous footshock. Peripheral specificity of quaternary naloxone was demonstrated by its lack of antagonism of morphine analgesia. These results suggest that a significant portion of the antinociception elicited by these parameters of footshock and assessed by tail-flick procedures in rats is due to the activation of peripheral endorphins.
mesh_terms: D000698:Analgesia; D000818:Animals; D004347:Drug Interactions; D004597:Electroshock; D004091:Hydromorphone / Q000031:analogs & derivatives*; D008297:Male; D009020:Morphine / Q000008:administration & dosage; D010111:Oxymorphone / Q000008:administration & dosage* / Q000145:classification; D010146:Pain; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000502:physiology; D013312:Stress, Physiological / Q000378:metabolism*
chemical_list: D009020:Morphine; D010111:Oxymorphone; D004091:Hydromorphone