烫伤大鼠细胞免疫抑制与肠源性内毒素血症的关系

The relationship between abnormalities of cell-mediated immunity and gut origin endotoxemia in a rat model of thermal injury

采用大鼠40%TBSAⅢ度烫伤模型,将动物随机分成烫伤对照组和选择性消化道脱污染(SI)D)防治组,探讨烫伤大鼠全身性细胞免疫抑制与肠源性内毒素血症的关系。结果显示,大鼠40%Ⅲ度烫伤后睥细胞对促有丝分裂原增殖应答反应、诱生白介素-2(IL-2)活性及 T 细胞亚群(Th/Ts)比值明显下降。预防性进行 SDD 动物,内毒素血症发生率显著降低,脾细胞增殖应答反应和 IL-2活性的诱生能力均明显恢复(P<O.05～0.01).但外周血中 Th/Ts 比值与对照组相比差异无显著意义(P>0.05)。提示烫伤所致肠道细菌/内毒素移位可能与诱发机体细胞免疫功能异常密切相关。SDD 预处理可防止动物细菌/内毒素移位,从而减轻创伤后的免疫抑制。

This study was conducted to determine the relationship between abnormalities of cell- mediated immunity and gut-derived endotoxemia in rats following burns.Animals were subjected to a 40% full-thickness scald injury,and randomly divided into control and selective decontamination of the digestive tract(SDD)treated groups.It was found that thermal injury resulted in marked reductions in splenocyte proliferative response to concanavalin A or phytohemagglutinin,interleukin 2(IL-2)produc- tion,and T helper/suppressor(Th/Ts)cells ratio.Prophylactic treatment with SDD significantly re- duced the incidence of endotoxemia,prevented suppressive mitogenic response and inadequacy in IL-2 production(P<0.05～0.01),but did not affect the abnormal ratio of Th/Ts in blood(P>0.05).We conclude that bacteria/endotoxin translocation from the gastrointestinal tract appears to be involved in cellular immune dysfunction after thermal injury.Pretreatment with SDD might attenuate systemic im- rnunosuppression by preventing translocation events.