地塞米松改善胶原性关节炎大鼠免疫功能与其血药浓度的相关性研究

Correlation between dexamethasone′s improving immune function and blood concentration in rats with collagen-induced arthritis

目的研究地塞米松对胶原诱导性关节炎(Collagen induced arthritis,CIA)大鼠炎症和免疫的调节作用。方法32只Wistar大鼠,分为3组,正常组10只、模型组11只,给药组11只。建立CIA模型后,给药组腹腔注射地塞米松(1 mg/kg),每周3次。连续给药4周后,处死并计算脾脏指数、胸腺指数。采用Real-time PCR方法检测脾淋巴细胞炎症因子IL-1β、IL-6、IL-17、TNF-α,转录因子T-bet、GATA3、RORγT、Foxp3mRNA的表达。HPLC法测大鼠地塞米松血药浓度,并将血药浓度与脾脏指数、Th亚型淋巴细胞亚群特异性转录因子做相关性分析。结果腹腔注射地塞米松能显著缓解CIA足爪肿胀、预防踝关节变形,降低脾脏指数、胸腺指数(P<0.01)。PCR结果显示,地塞米松抑制CIA大鼠脾淋巴细胞中炎症因子,并改善Th1/Th2、Th17/Treg的失衡(P<0.05)。HPLC法检测大鼠地塞米松平均血药浓度为0.1738μg/ml。血药浓度与脾脏指数呈负相关,与T-bet、RORγT呈负相关,与GATA3、Foxp3呈正相关。结论地塞米松对CIA大鼠具有强大的抗炎和免疫调节作用。

Objective To investigate the regulating effects of dexamethasone on inflammation and immunization of rats with collagen-induced arthritis.Methods Totally 32 Wistar rats were randomly divided into 3 groups(normal group,n=10;model group,n=11;administration group,n=11).After the CIA model was established,dexamethasone(1 mg/kg)was injected intraperitoneally in the administration group,3 times a week for 4 consecutive weeks.Spleen index and thymus index were calculated.The expression of spleen lymphocyte inflammation factor IL-1β,IL-6,IL-17,TNF-αand transcription factors T-bet,GATA3,RORγT and Foxp3 mRNA was measured by Real-time PCR.The dexamethasone blood concentration was measured by HPLC and a correlation analysis of blood drug concentration with spleen index and Th subtype lymphocyte subset-specific transcription factors was made.Results Dexamethasone could significantly alleviate CIA foot swelling,prevent ankle joint deformation and decrease the spleen index and thymus index(P<0.01).PCR results showed that dexamethasone inhibited the inflammatory factors in spleen lymphocytes of CIA rats,and improved the imbalance of Th1/Th2 and Th17/Treg(P<0.05).The average blood drug concentration of dexamethasone in rats measured by HPLC was 0.1738μg/ml.Serum concentration was negatively correlated with spleen index,and negatively correlated with T-bet and RORγT,while positively correlated with GATA3 and Foxp3.Conclusion Dexamethasone has strong anti-inflammatory and immunosuppressive effects on CIA rats.