title: Central oxytocin enhances antinociception in the rat.
abstract: 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.
authors.affiliation: Institute for Pharmaceuticals and Medical Science, Guangdong Bangmin Pharmaceutical Co. Ltd., Jianghai Distract, Jiangmen, Guangdong 529080, China. yj6676@yahoo.com
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Chen
authors.forename: Wen-Yan
authors.initials: WY
authors.lastname: Liu
authors.forename: Cheng-Hai
authors.initials: CH
authors.lastname: Wang
authors.forename: Bao-Chen
authors.initials: BC
authors.lastname: Lin
mesh_terms: 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
chemical_list: D007106:Immune Sera; D010121:Oxytocin