选择性消化道脱污染对烫伤大鼠白细胞介素-18及相关介质表达的影响

目的：探讨选择消化道脱污染对烫伤大鼠白细胞介素－18及相关介质表达的影响。方法：采用大量30％体表面积Ⅲ度烫伤模型,组织IL－18、IFN－γ、FasL mRNA含量采用逆转录聚合酶链式反应检测,IFN－γ蛋白含量采用ELISA法测定。结果：烫伤组织IL－18 mRNA表达较伤前值即有显著升高,8h达高峰,且一直持续至伤后24h;烫伤后组织IFN－γ mRNA表达开始增加,伤后8h达高峰、肠、肺组织IFN－γ水平与基因表达趋势基本一致,未致伤动物肠、肺可表达少量FasL mRNA,烫伤可使其表达增加。相关分析表明,组织IL－18 mRNA表达与IFN－γ mRNA、IFN－γ水平、FasL mRNA表达均呈显著正相关,结论：肠、肺组织IL－18 mRNA表达在烫伤早期即显著增多,并呈一逐渐升高的趋势,创伤后组织IL－18 mRNA基因表达对IFN－γ、FasL的生成具有重要影响。SOD预治疗后可不同程度抑制IL－18及相关介质表达的表达。

The effect of selective decontamination of the digestive tract on interleukin-18 mRNA expression in thermal injured rats

Objective　To　investigate　the　effect　of　selective　decontamination　of　the　digestive　tract　on　interleukin-18　mRNA　expression　in　thermal　injured　rats．Methods　The　animals　were　subjected　to　a　30％　total　body　surface　area　full-thickness　thermal　injury,fluid　resuscitation　were　performed　at　6　hour　aftev　burns．54　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．Cytokine　mRNA　expression　were　semi-quantitated　by　the　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　at　2　hour,peaking　at　8　hour,and　a　high　level　was　maintained　till　24　hour．However,treatment　with　SDD　could　lower　systemic　endotoxin　levels,and　markedly　inhibit　IL-18、IFN-γ、FasL　mRNA　expression．In　addition,positive　correlation　between　IL-18　mRNA　expression　and　IFN-γ　mRNA　expression,IFN-γ　level,FasL　mRNA　expression　were　noted（r＝0.716～0.905,P＜0.01）．Conclusion　This　study　suggests　that　major　burns　can　lead　to　a　marked　elevation　of　tissue　IL-18　mRNA　expression　in　vital　organs,Treatment　with　SDD　can　effectively　block　IL-18　pathway　and　excessive　inflammation　response　secondary　to　major　burns．