Effect of oxytocin on acupuncture analgesia in the rat.
Oxytocin has been demonstrated to be involved in pain modulation. Acupuncture analgesia is a very useful clinical tool for pain relief, which has over 2500-year history in China. The present study investigated the role of oxytocin in acupuncture analgesia in the rat through oxytocin administration and measurement. Central administration of oxytocin (intraventricular injection or intrathecal injection) enhanced acupuncture analgesia, while central administration of anti-oxytocin serum weakened acupuncture analgesia in a dose-dependent manner. However, intravenous injection of oxytocin or anti-oxytocin serum did not influence acupuncture analgesia. Electrical acupuncture of "Zusanli" (St. 36) reduced oxytocin concentration in the hypothalamic supraoptic nucleus, and elevated oxytocin concentration in the hypothalamic suprachiasmatic nucleus, hypothalamic ventromedial nucleus, thalamic ventral nucleus, periaqueductal gray, raphe magnus nucleus, caudate nucleus, thoracic spinal cord and lumbar spinal cord, but did not alter oxytocin concentration in the hypothalamic paraventricular nucleus, anterior pituitary, posterior pituitary and plasma. The data suggested that oxytocin in central nervous system rather than in peripheral organs is involved in acupuncture analgesia.
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-Cheng
BC
D026881:Acupuncture; D000698:Analgesia; D000818:Animals; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D004558:Electric Stimulation; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D010121:Oxytocin / Q000008:administration & dosage / Q000494:pharmacology*; D010146:Pain / Q000517:prevention & control*; D010902:Pituitary Gland / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology
D010121:Oxytocin