[Role of locus coeruleus in analgesia caused by stimulation of supraoptic nucleus].
The effects of stimulation of supraoptic nucleus (SON) on the changes of oxytocin (OT), arginine vasopressin (AVP), norepinephrine (NE) and serotonin (5-HT) in the perfusate of locus coeruleus (LC) and changes of pain threshild (PT) were studied by methods of microinjection, radioimmunoassay (RIA) and high pressure liquid chromatography (HPLC) technique. The results showed that the OT contents at 30, 60 and 90 min after stimulation, that of AVP at 30 min and 5-HT at 60 min were increased significantly, while the NE contents at 30 and 60 min were decreased markedly. Injection of V1 antagonist into LC did not affect the analgesic effect caused by administration of L-glutamic acid (L-Glu) into SON, which, however, could be partially inhibited by V2 antagonist or even reversed by OT antagonist. The above results suggested that the analgesic effect due to stimulation of SON is caused by increase of 5-HT and decreases of NE in the LC though the action of OT released by SON on OT and V2 receptor in LC.
D000698:Analgesia; D000818:Animals; D018698:Glutamic Acid / Q000494:pharmacology; D008125:Locus Coeruleus / Q000378:metabolism / Q000502:physiology*; D008297:Male; D008845:Microinjections; D009638:Norepinephrine / Q000378:metabolism; D010121:Oxytocin / Q000378:metabolism; D017288:Pain Threshold; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism; D013495:Supraoptic Nucleus / Q000502:physiology*
D012701:Serotonin; D018698:Glutamic Acid; D010121:Oxytocin; D009638:Norepinephrine