烫伤大鼠肠、肺组织白细胞介素-18的表达及其对脏器的影响

Dynamic changes of interleukin-18 expression in thermal injured rats and its effect on organ dysfunction

目的 探讨大鼠严重烫伤后肠、肺组织IL 1 8(白细胞介素 1 8,Interleukin 1 8)和相关介质的动态表达规律及其对脏器的影响。方法 采用大鼠 30 %体表面积Ⅲ度烫伤延迟复苏模型 ,肠、肺组织IL 1 8、IFN γ、FasL(Fas配体 ,FasLigand)mRNA含量采用逆转录聚合酶链式反应检测。ELISA法测定IFN γ含量 ;同时检测肠、肺功能指标。结果 肠、肺组织IL 1 8、IFN γ、FasLmRNA表达较伤前显著升高 ,烫伤后 8小时达高峰 ,且一直持续至伤后 2 4小时 ,给予SDD(选择性消化道脱污染selectivedecontaminationofthedigestivetract)预治疗后 ,不同程度抑制了IL 1 8、IFN γ、FasLmRNA的表达。严重烫伤后 ,出现广泛的脏器功能损害 ,预防性SDD处理可不同程度地保护脏器。相关分析表明 ,循环内毒素与肠、肺IL 8、IFN γ、FasL诱生有关 ,而后者与器官功能损害密切相关。结论 肠、肺组织IL 8、IFN γ、FasLmRNA表达在烫伤早期即显著增多 ,并呈逐渐升高的趋势 。

Objtective To investigate the dynamic changes of interleukin 18(IL 18)expression and its effect on organ dysfunction.?Methods Animals were subjected to a 30% total body surface area full thickness thermal injury,fluid resuscitation was performed at 6 hours post burns.Fifty four male Wistar rats were randomly divided into three groups:normal controls,30% Ⅲ injury group,and selective decontamination of the digestive tract(SDD) treatment group.Plasma endotoxin was measured by limulus amebocyte lysate test,cytokine mRNA expression was semi quantitated by reverse transcription polymerase chain reaction(RT PCR) using GAPDH as an internal standard.Enzyme linked immunosorbent assay(ELISA) was performed for IFN γ measurement.Results IL 18?IFN γ?FasL mRNA expression significantly increased in intestine,lung at 2 hours,peaking at 8 hours,the high level was maintained till 24 hours,However,treatment with SDD could markedly inhibit IL 18?IFN γ?FasL mRNA expression in various organs.Intestinal DAO.pulmonary MPO activities markedly increased after burns,treatment with SDD could improve ogran functional lesion.There were positive correlations between plasma endotoxin and tissue IL 18?IFN γ?FasL mRNA expression,IFN γ level.Similar results were also obtained betwwen cytokine mRNA expression and organ function parameters.Conclusion This study suggests that major burns can lead to a marked elevation of tissue Il 18 and IFN γ?FasL mRNA expression in vital organs,which might be associated with the damage of organ function.