地塞米松对CIA大鼠DRG中炎症因子的抑制和关节疼痛的改善作用

Dexamethasone inhibits inflammatory factors in DRG and improves joint pain of CIA rats

目的研究地塞米松对胶原诱导性关节炎(collagen induced arthritis,CIA)大鼠关节疼痛的改善作用。方法除10只正常组外,其余22只Wistar大鼠被随机平均分模型组和给药组、建立CIA模型,给药组腹腔注射地塞米松(1 mg·kg^-1),每周3次,连续4周。Von Frey法测机械性缩足反射阈值。给药4周后,处死并采集血清、滑膜、背根神经节(dorsal root ganglion,DRG)。采用Real-time PCR方法检测滑膜和DRG中炎症因子IL^-1β、IL-6、IL^-17、TNF-α以及DRG中疼痛指标神经肽Y、瞬时感受器电位香草酸受体1、神经生长因子以及脑源性神经营养因子的mRNA的表达。酶联免疫吸附法(enzyme-linked immunosorbent assay,ELISA)测定大鼠血清中IL^-17A和TGF-β1的含量。结果地塞米松能明显降低CIA大鼠滑膜、DRG以及血清中炎症因子的表达,提高TGF-β1表达;降低DRG中疼痛相关因子表达水平,从而起到缓解CIA关节疼痛的作用。结论地塞米松对CIA大鼠具有缓解局部关节炎症和缓解疼痛的作用。

Aim To study the effects of dexamethasone on pain in collagen induced arthritis(CIA)rats.Methods Except 10 rats as normal group,22 Wistar rats were randomly divided into model group and administration group.After the CIA model was established,dexamethasone(1 mg·kg^-1)was injected intraperitoneally in the administration group 3 times a week for 4 weeks.Von Frey method was used to determine the mechanical withdrawal threshold(MWT)of hind paw in rats.Four weeks after the administration,the sera,synovial membrane,and DRGs were collected.Real-time PCR was used to detect not only the inflammatory factors IL^-1β,IL-6,IL^-17,TNF-αin DRG and synovium but also pain indicator in DRG,such as neuropeptide Y(Neuropeptide Y,NPY),transient receptor potential vanilloid^-1(TRPV1),NGF,BDNF.The contents of IL^-17A and TGF-β1 in rat serum were determined using enzyme-linked immunosorbent assay(ELISA).Results Dexamethasone decreased not only the expression of inflammatory factors in synovium,DRG and serum of CIA rats,but also decreased the expression of pain indicators in DRG and increased transforming growth factorβ1 levels thereby playing a role in relieving CIA joint pain.Conclusions Dexamethasone can relieve local arthritis and relieve pain in CIA rats.