Anti-nociceptive effects of oxytocin in rats and mice.
The existence of neural opioid-mediated networks that are specific for the modulation of nociception is well established. Parallel non-opioid pathways exist, but their underlying physiology is little known. We now report that oxytocin administered intraperitoneally to rats, and intraperitoneally or intracisternally to mice has an anti-nociceptive effect, which is related to the activation of descending anti-nociceptive pathways. This anti-nociceptive effect can be reversed by an oxytocin antagonist but not by the opioid antagonist naloxone. The anti-nociceptive effect of oxytocin is not directly dependent on the activation of serotonergic pathways or to changes in temperature. Our data indicate that the oxytocinergic system has a modulatory function on nociception.
Lundeberg
T
T
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Uvnäs-Moberg
K
K
Agren
G
G
Bruzelius
G
G
D000700:Analgesics / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D002946:Cisterna Magna; D004347:Drug Interactions; D007267:Injections; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D010121:Oxytocin / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010147:Pain Measurement / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D012881:Skin Temperature / Q000502:physiology
D000700:Analgesics; D009270:Naloxone; D010121:Oxytocin