小鼠烧伤创面脓毒症模型的建立与评价

Establishment and evaluation of a murine burn wound sepsis model

目的建立一种稳定的小鼠烧伤创面脓毒症模型,检测其病理生理指标,为烧伤脓毒症相关研究提供标准化的动物模型。方法将小鼠背部侵入90℃水面接触8 s建立小鼠Ⅲ度烫伤模型,烫伤面积约15%~20%。2 h后痂下注射100μL浓度为0.75×10^(5) CFU/mL的铜绿假单胞菌(Pseudomonas aeruginosa,PA)造伤后创面脓毒症。连续12 d观测记录小鼠的体重、采食量、生存率和一般状态指标。在注射后1、2、3、5、7 d取小鼠外周血和肝组织,测定血清生化和炎症因子指标,观察肝组织病理改变。结果模型组建模后12 d的死亡率为30.2%。血清生化指标中ALT、AST、UREA和CREA均较建模前显著上升(P<0.05或P<0.01),TP和TBIL指标无明显变化。血清炎症指标中TNF-α、IL-6在建模后第1天升至最高值(P<0.01),随后逐日递减,分别至第3、7天恢复至造模前水平。肝组织病理切片结果显示在各个时相点均出现肝损伤表现。结论建立了操作简便可控、严重程度适宜的烧伤脓毒症模型,符合烧伤脓毒症的病理生理特点,可为相关机制研究和药物研发提供标准化的实验动物模型。

Objective To establish a stable mouse burn wound sepsis model,determine its pathophysiological indicators,and provide a standardized animal model for the study of burn sepsis.Methods The back of a mouse was exposed for 8 s to water with a temperature of 90℃to establish a third degree scald model,and the scald area was about 15%~20%.Two hours later,100μL of Pseudomonas aeruginosa(PA)with a concentration of 0.75×10^(5) colony-forming units/mL was injected under the eschar to create wound sepsis.The bodyweight,feed intake,survival rate and general status of the mice were observed and recorded for 12 days.Peripheral blood and liver tissues were collected from the mice on post-infection days 1,2,3,5 and 7,the serum biochemical and inflammatory factors were measured,and the pathological changes of liver tissues were observed.Results The mortality of the model mice on the twelfth day postinfection was 30.2%.The levels of the serum biochemical indexes ALT,AST,UREA and CREA were significantly increased from baseline(P<0.05 or P<0.01),whereas the levels of TP and TBIL exhibited no obvious changes.The serum inflammatory indexes TNF-αand IL-6 increased to their highest values on the first day after infection(P<0.01)and then decreased daily,recovering to their baseline levels on the third and seventh days post-infection,respectively.The histopathological sections of liver revealed liver injury at all tested timepoints.Conclusions A simple burn sepsis model with a manageable protocol and appropriate severity was established;the model characteristics are in line with the pathophysiological characteristics of burn sepsis;and this approach can provide a standardized experimental animal model both for relevant mechanism research and for drug research and development.