The effect of naloxone on C-fiber reflex in cats.
The specific opiate antagonist naloxone rapidly reverses hypotension caused by endotoxin, hypovolemia and spinal transection. The fact that naloxone appears to act as a causative level to improve shock pathophysiology, as well as its extensive clinical use for opiate overdose, makes this drug a particularly clinical use for opiate overdose, makes this drug a particularly attractive potential therapeutic agent for the treatment of shock in humans. The electrophysiological effects of naloxone were studied on c-fiber reflex in spinal and intact cats. The drugs were injected in to the right cephalic vein. Results can be summarized as follows: Naloxone in the intact cat had a more pronounced facilitating effect than in the spinal cat. Naloxone given as a one shot injection was more potentiating than naloxone given as a 5 minute injection. Naloxone antagonized the facilitation of a small dose of ketamine-HCL in the intact cat and also the depression of a large dose ketamine-HCL. Naloxone antagonized capsaicin on c-fiber reflex. This result supports that naloxone has the antagonizable inhibitory effect of substance-P. Naloxone for the first injection had an effective response but additional naloxone did not facilitate the c-fiber reflex.
D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D002415:Cats; D005260:Female; D007649:Ketamine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D012018:Reflex / Q000187:drug effects*; D013116:Spinal Cord / Q000502:physiology
D009270:Naloxone; D007649:Ketamine; D002211:Capsaicin