地塞米松对创伤失血性休克大鼠T淋巴细胞功能的影响

Effects of dexamethasone on T-lymphocytes in rats with traumatic-hemorrhagic shock

目的 探讨地塞米松对创伤失血性休克大鼠T淋巴细胞的功能的影响。方法 制作创伤失血性休克大鼠动物模型 ,随机分为正常对照组、创伤失血性休克组、创伤失血性休克地塞米松处理组。分别于模型完成的 1、 2、 3、 6、 12h时间点测血浆TNF α水平 ,将各组各时间点大鼠活杀 ,取肺、脾做病理学检查 ,创伤失血性休克组在 2h和 6h时将动物杀死后取脾行电镜检查。并取各组各时间点脾做免疫组化IL 2、IL 4标记。结果 大鼠创伤失血性休克后 ,血浆INF α水平持续增高 ,6h达高峰。光镜下肺脏组织损伤 ,脾小体早期增生 ,后期出现萎缩。电镜显示 ,脾小体增生期腺淋巴细胞增殖活化 ,萎缩期脾淋巴细胞坏死。免疫组化显示脾小体增生期以IL 2表达为主 ,萎缩期以IL 4表达为主。地塞米松能显著降低血浆TNF α表达水平 ,减轻脾、肺组织损伤 ,光镜下脾小体持续增生 ,免疫组化标记结果变化不大。结论 创伤失血性休克大鼠早期T淋巴细胞激活 ,随后出现了向TH2 的漂移 ,最后淋巴细胞功能衰竭。原因是早期应用地塞米松抑制了过度的炎症反应 。

Objective To investigate the effects of dexamethasone on T-lymphocytes of rats with traumatic-hemorrhagic shock.Methods The model of traumatic-hemorrhagic shock was established.Seventy-fire rats were randomly divided into three groups:normal control group(n=25),traumatic-hemorrhagic shock group(n=25),and dexamethasone-treated group(n=25).TNF-α in plasma of rats in each group were measured at 1,2,3,6 and 12 h after shock.In each group,rats were killed,and the pathological changes of spleen lymphocyte and lung were examined by light microscopy at different time poimts .Meanwhile,at 2 h and 6 h,the pathological changes of spleen lymphocyte were examined by transmission electron microscopy with immunohistochemistry technology.IL-2 and IL-4 in spleen were detected by immunohistochemistry.Results After traumatic-hemorrhagic shock,the expression of TNF-α increased evidently and peaked at 6h.Splenic corpuscle hyperplasia at the early phase and atrophy at the later phase were observed under light microscopy.Under transmission electron microscopy,hyperplasia and activation of T-lymphocytes were observed during splenic corpuscle hyperplasia period;necrosis of T-lymphocytes was observed during splenic corpuscle atrophy period.IL-2 was expressed during splenic corpuscle hyperplasia period,while IL-4 was expressed during splenic corpuscle atrophy period.The administration of dexametha sone inhibited the expression of TNF-α and alleviated the pulmonary and spleen damage.Splenic corpuscle hyperplasia persisted and the immunohistochemistry markers did not change significantly.Conclusion T-lymphocytes are activated in traumatic-hemorrhagic shock rats initially,with a TH 2 shift later,and T-lymphocytes function fails finally.dexametha sone inhibits inflammatory responses,alleviates organ damage,and preserves function of T-lymphocytes.