title: [Effects of repeated electroacupuncture on gene expression of cannabinoid receptor-1 and dopamine 1 receptor in nucleus accumbens-caudate nucleus region in inflammatory-pain rats].
abstract: OBJECTIVE
  To observe the effect of repeated electroacupuncture (EA) on the expression of cannabinoid receptor-1 (CB 1) mrRNA and dopamine 1 receptor (D 1) mRNA in Nucleus Accumbens (NAC)-Caudate Nucleus (CN) region in inflammatory-pain rats, so as to study its underlying mechanism in analgesia.
  
  
  METHODS
  A total of 30 SD rats were randomized into normal control, model, EA, EA+ AM 251 and WIN 55212-2 groups, with 6 cases in each group. EA (2 Hz/100 Hz, 1 -3 mA) was applied to "Zusanli"(ST 36) and "Kunlun"(BL 60) for 30 min, once every other day, and 4 sessions all together. Arthritis model was established by injection of Freund's complete adjuvant 0.05 mL in the rat's left ankle. Thermal pain threshold (paw withdrawal latency, PWL) was detected before and after modeling and after repeated EA and/or intraperitoneal injection of AM 251(an inverse antagonist at the CB 1 cannabinoid receptor, 0. 1 mg/100 g) and WIN 55212-2 (a potent cannabinoid receptor agonist, 0. 2 mg/100 g). The expression of CB 1 receptor mRNA and D 1 receptor mRNA in the NAC-CN region was measured by real time fluorescence quantitative-polymerase chain reaction.
  
  
  RESULTS
  Compared with the control group, the pain threshold values of the model group was decreased significantly (P<0.01). In comparison with the model group, the pain threshold values of the EA group and WIN 55212-2 group were increased considerably on day 10 (P<0. 01). No significant differences were found between the EA+ AM 251 and model groups and between the EA and WIN 55212-2 groups in PWL after the treatment (P>0.05). Compared with the control group, both CB 1 R mRNA and D 1 R mRNA expression levels in the model group were increased slightly, while in comparison with the model group and EA+ AM 251 group, CB 1 R mRNA and D 1 R mRNA expression levels in the EA group and WIN 55212-2 group were upregulated obviously. No significant differences were found between the EA + AM 251 and model groups and between the EA and WIN 55212-2 groups in CB 1 R mRNA and D 1 R mRNA expression levels.
authors.affiliation: Yueyang Hospital of Integrated Chinese and Western Shanghai University of Chinese Medicine, Shanghai 200437, China. S_Showing@hotmail.com
authors.forename: Yin
authors.initials: Y
authors.lastname: Shou
authors.forename: Ying-qian
authors.initials: YQ
authors.lastname: Zhao
authors.forename: Ming-shu
authors.initials: MS
authors.lastname: Xu
authors.forename: Lin-bao
authors.initials: LB
authors.lastname: Ge
mesh_terms: D015667:Acupuncture Analgesia; D015669:Acupuncture Points; D000818:Animals; D001168:Arthritis / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D002421:Caudate Nucleus / Q000276:immunology*; D004195:Disease Models, Animal; D015671:Electroacupuncture; D015870:Gene Expression; D006801:Humans; D008297:Male; D009714:Nucleus Accumbens / Q000276:immunology*; D010146:Pain / Q000235:genetics / Q000276:immunology; D059408:Pain Management; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D043884:Receptor, Cannabinoid, CB1 / Q000235:genetics* / Q000276:immunology; D011954:Receptors, Dopamine / Q000235:genetics* / Q000276:immunology
chemical_list: C543264:Cnr1 protein, rat; D043884:Receptor, Cannabinoid, CB1; D011954:Receptors, Dopamine