Central oxytocin enhances antinociception in the rat.
The study aimed to investigate the effect of oxytocin on antinociception in the rat. The pain threshold was elevated by oxytocin following intraventricular (icv) or intrathecal injection (ith), and reduced by anti-oxytocin serum (icv or ith). But the pain threshold was not altered by intravenous injection (iv) of oxytocin or anti-oxytocin serum. Pain stimulation induced oxytocin concentration decrease in the hypothalamic supraoptic nucleus, and increase in the locus coeruleus, raphe magnus nucleus, caudate nucleus and spinal cord, but no change in the hypothalamic paraventricular nucleus and plasma. The results indicated that central, not peripheral oxytocin could enhance antinociception.
Yang
Jun
J
Institute for Pharmaceuticals and Medical Science, Guangdong Bangmin Pharmaceutical Co. Ltd., Jianghai Distract, Jiangmen, Guangdong 529080, China. yj6676@yahoo.com
Yang
Yu
Y
Chen
Jian-Min
JM
Liu
Wen-Yan
WY
Wang
Cheng-Hai
CH
Lin
Bao-Chen
BC
D000818:Animals; D004305:Dose-Response Relationship, Drug; D007106:Immune Sera / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology; D007275:Injections, Intravenous; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D010121:Oxytocin / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000187:drug effects*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000503:physiopathology; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000503:physiopathology; D013493:Suprachiasmatic Nucleus / Q000187:drug effects / Q000503:physiopathology
D007106:Immune Sera; D010121:Oxytocin