大肠杆菌DNA诱导大鼠TNF-α IL-6释放的初步研究及意义

Primary research on release of TNF-α and IL-6 induced by Escherichia coli DNA and its significance

目的了解细菌DNA是否参与诱导了SIRS的发生及可能机制。方法抽提大肠杆菌DNA,60Co辐照去除内毒素;分别以10mg/kg60CoDNA和LPS注射Wistar大鼠(n=4),ELISA法检测药后1、3、6、12、24h血浆TNFα、IL6水平。结果大鼠60CoDNA与内毒素组血浆TNFα、IL6的变化趋势相似,TNFα分别于1和3h达高峰,为27162u/ml和4496u/ml(P<005);IL6于3h达到峰值,持续至6h,两组无显著差异(P>005)。结论大肠杆菌DNA可介导SIRS发生,其机制可能是通过启动细胞因子的级联反应。

Objective: To investigate the effects of Escherichia coli DNA on systemic inflammatory response syndrome. Methods: The Escherichia coli genome DNA and its fragments were extracted from 25922 strains of Escherichia coli and the activity of lipopolysaccharide in these DNA was deactivated by 60 Co irradiation( 60 Co DNA). The 60 Co DNA(30 mg/kg) and lipopolysaccharide(10 mg/kg) were injected into hearts of Wistar rats through a cardiac catheter, respectively, and then the plasma levels of TNF-αand IL-6 were detected at 0, 1, 3, 6, 12, 24 h after injection.Results: The change tendency and magnitude of plasma TNF-αand IL-6 were similar in both groups. After injection, the high peak level of plasma TNF-αappeared at 1 h in 60 Co DNA group(n=4) and 3 h in lipopolysaccharide group(n=4), respectively; The high peak level of IL-6 appeared later in 60 Co DNA group(6 h) than that in lipopolysaccharide group(3 h), respectively. There was not significant difference between groups. Conclusion: Escherichia coli DNA may induce the systemic inflammatory response syndrome by stimulating cytokine release.