title: [Effect of triptolide on iNOS and SP expressions in spinal dorsal horn and dorsal root ganglion of rats with adjuvant arthritis].
abstract: OBJECTIVE
  To observe the analgesic effect of triptolide (TP) of high, middle and low doses on rats with adjuvant arthritis (AA), and the expressions of inducible nitric oxide synthase (iNOS) and substance P (SP) in spinal dorsal horn and dorsal root ganglion (DRG) of corresponding sections, in order to discuss the possible mechanism for the analgesic effect of TP on rats with adjuvant arthritis.
  
  
  METHODS
  Fifty SD rats were selected and randomly divided into the normal group (group A), the model group (group B), and TP low (group C), middle (group D), high (group E) dose groups. Except for the group A, all of the remaining groups were injected with 0.1 mL of Freund's complete adjuvant through their right rear toes to establish the model. At 14 d after the model establishment, rats in C, D and E groups were intraperitoneally injected with different doses of TP (0.1 mg x kg(-1) for the group C, 0.2 mg x kg(-1) for the group D, 0.4 mg x kg(-1) for the group E) once a day for 9 days. Then the 50% mechanical withdraw threshold (MWT) was determined. And the expressions of iNOS and SP in lumbar5 (L5) spinal dorsal horn and DRG were detected with the immunohistochemical method.
  
  
  RESULTS
  The 50% MWT of rats in the group B was significantly lower than that of the group A (P < 0.01). After being treated with TP, the Thermal withdrawal latencies of groups C, D and E were significantly higher than that of the group B (P < 0.01). TP could notably increase the MWT of AA rats, with a certain dose-effect relationship. The immunohistochemical results indicated that the iNOS and SP expressions significantly increased in the group B (P < 0.01), while the positive expression levels of iNOS and SP in groups C, D and E were significantly lower than that of the group B (P < 0.01), with a certain dose-effect relationship.
  
  
  CONCLUSIONS
  TP shows a good analgesic effect on AA, and could inhibit the iNOS and SP expressions in spinal dorsal horn and DRG in rats with adjuvant arthritis, which may be one of action mechanisms for the analgesic effect of TP.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Zhang
authors.forename: Zhuo-Hui
authors.initials: ZH
authors.lastname: Lu
authors.forename: Deng-Ming
authors.initials: DM
authors.lastname: Wei
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001169:Arthritis, Experimental / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D004224:Diterpenes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004852:Epoxy Compounds / Q000494:pharmacology; D005260:Female; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D010147:Pain Measurement / Q000379:methods; D010616:Phenanthrenes / Q000494:pharmacology*; D008517:Phytotherapy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism; D013373:Substance P / Q000096:biosynthesis*; D013997:Time Factors; D016896:Treatment Outcome; D029757:Tripterygium / Q000737:chemistry
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004224:Diterpenes; D004852:Epoxy Compounds; D010616:Phenanthrenes; C001899:triptolide; D013373:Substance P; D052247:Nitric Oxide Synthase Type II