炎性反应在胸部撞击和胸部撞击-失血性休克复苏致大鼠急性肺损伤中作用的比较

Comparison of roles of inflammatory response in acute lung injury induced by blunt chest trauma versus by blunt chest trauma-hemorrhagic shock and resuscitation in rats

目的 比较炎性反应在胸部撞击和胸部撞击-失血性休克复苏“双重打击”致大鼠急性肺损伤中的作用.方法 雄性SD大鼠30只,8周龄,体重240 ～ 280 g,采用随机数字表法,将其分为3组（n=10）：假手术组（S组）、胸部创伤组（T组）和胸部创伤-失血性休克复苏组（THSR组）.将砝码（300g）于95 cm高处自由落体,撞击大鼠心前区,制备胸部撞击模型,5 min后经左侧股动脉放血,使MAP在15 min内降至35 ～ 45 mmHg,并维持60 min,然后进行复苏,制备胸部撞击-失血性休克复苏“双重打击”模型.于模型制备后6h时,取右侧颈动脉血样,行血气分析,采用ELISA法测定血清TNF-α、IL-6、IL-1β和IL-10的浓度.然后处死大鼠,取肺组织,光镜下观察病理学结果,电镜下观察超微结构,采用ELISA法测定肺组织TNF-α、IL-6、IL-1β和IL-10的含量.结果 与S组比较,T组和THSR组PaO2降低,血清和肺组织TNF-α、IL-6、IL-1β和IL-10的水平升高（P＜0.05）;与T组比较,THSR组PaO2降低,血清和肺组织TNF-α、IL-6、IL-1β和IL-10的水平升高（P＜0.05）.THSR组肺组织病理学损伤较T组加重.结论 与在胸部撞击致大鼠急性肺损伤中的作用比较,炎性反应在胸部撞击-失血性休克复苏“双重打击”致大鼠急性肺损伤中的作用明显增强.

Objective To compare the roles of inflammatory response in acute lung injury （ALI） induced by blunt chest trauma verus by blunt chest trauma-hemorrhagic shock and resuscitation （double hits） in rats.Methods Thirty male Sprague-Dawley rats,aged 8 weeks,weighing 240-280 g,were randomly assigned into 3 equal groups （n =10 each） using a random number table：sham operation group （S group）,blunt chest trauma group （T group）,and blunt chest trauma and hemorrhagic shock and resuscitation group （THSR group）.Lung contusion was induced in anesthetized rats by dropping a 300 g weight onto a precordial protective shield to direct the impact force away from the heart and toward the lungs.Blood was withdrawn via the left femoral artery 5 min later until MAP was decreased to 35-45 mmHg within 15 min and maintained at this level for 60 min,followed by resuscitation.At 6 h after the model was established,the arterial blood samples were collected for blood gas analysis and detection of serum concentrations of tumor necrosis factor-α （TNF-α）,interleukin-6 （IL-6）,IL-1β and IL-10 （by ELISA）.The rats were then sacrificed and pulmonary specimens were obtained for determination of contents of TNF-α,IL-6,IL-1β and IL-10 in lung tissues and for microscopic examination.Results Compared with group S,PaO2 was significantly decreased,and the levels of TNF-α,IL-6,IL-1β and IL-10 in serum and lung tissues were increased in T and THSR groups.Compared with group T,PaO2 was significantly decreased,and the levels of TNF-α,IL-6,IL-1β and IL-10 in serum and lung tissues were increased in group THSR.The histopathological damage to lung tissues was aggravated in THSR group as compared with T group.Conclusion The role of inflammatory response in ALI induced by blunt chest trauma-hemorrhagic shock and resuscitation （double hits） is significantly stronger than that in ALI induced by blunt chest trauma alone in rats.