盐酸戊乙奎醚对胸部撞击-失血性休克/复苏致大鼠急性肺损伤的影响

Effects of penehyclidine hydrochloride on acute lung injury induced by blunt chest trauma-hemorrhagic shock and resuscitation in rats

目的 探讨盐酸戊乙奎醚对胸部撞击-失血性休克/复苏致大鼠急性肺损伤的影响.方法 健康雄性SD大鼠40只,体重250～300 g,8周龄,采用随机数字表法将其分为4组（n=10）：假手术组（S组）、胸部撞击-失血性休克/复苏组（THSR组）、盐酸戊乙奎醚预防组（P1组）和盐酸戊乙奎醚治疗组（P2组）.THSR组、P1组和P2组制备胸部撞击-失血性休克/复苏致急性肺损伤模型：将砝码（300g）于95 cm高处自由落体,撞击大鼠心前区,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.P1组于胸部撞击前30 min时静脉注射盐酸戊乙奎醚2mg/kg;P2组于失血性休克后60 min时静脉注射盐酸戊乙奎醚2 mg/kg.模型制备后6h,采集动脉血样进行血气分析,计算氧合指数（OI）,采用ELISA法测定血清IL-6和IL-1β的浓度.取血后处死大鼠,收集肺泡灌洗液（BALF）,行白细胞计数,测定蛋白浓度;取肺组织,光镜和电镜下观察肺组织病理学结果,采用Western blot法检测Toll样受体4（TLR4）和磷酸化p38丝裂原活化蛋白激酶（p-p38MAPK）的表达.结果 与S组比较,THSR组、P1组和P2组PaO2和OI降低,PaCO2、BLAF蛋白浓度、白细胞计数和血清IL-6、IL-1β的浓度升高,肺组织TLR4和p-p38MAPK的表达上调（P＜0.05）;与THSR组比较,P1组和P2组PaO2和OI升高,PaCO2、BLAF蛋白浓度、白细胞计数和血清IL-6、IL-1β的浓度降低,肺组织TLR4和p-p38MAPK表达下调（P＜0.05）;P1组和P2组上述各指标比较差异无统计学意义（P＞0.05）.结论 盐酸戊乙奎醚可减轻胸部撞击-失血性休克/复苏致大鼠急性肺损伤,其机制可能与抑制TLR4/p38MAPK信号通路的激活,减轻炎性反应有关.

Objective To investigate the effects of penehyclidine hydrochloride （PHC） on acute lung injury induced by blunt chest trauma-hemorrhagic shock and resuscitation in rats.Methods Forty male SpragueDawley rats,aged 8 weeks,weighing 250-300 g,were randomly assigned into 4 equal groups （n =10 each） using a random number table：sham operation group （S group）,blunt chest trauma combined with hemorrhagic shock and resuscitation group （group THSR）,PHC for prevention group （group P1）and PHC for treatment group （group P2）.ALI was induced by dropping a 300 g weight onto a precordial protective shield to direct the impact force away from the heart and toward the lungs in anesthetized rats in THSR,P1 and P2 groups.Blood was withdrawn via the femoral artery 5 min later until MAP was decreased to 35-45 mmHg within 15 min and maintained at this level for 60 min,followed by resuscitation.In P1 group,PHC 2 mg/kg was injected intravenously at 30 min before blunt chest trauma.In P2 group,PHC 2 mg/kg was injected intravenously at 60 min after hemorrhagic shock.At 6 h after the model was established,arterial blood samples were obtained for blood gas analysis and for measurement of concentrations of interleukin-6 （IL-6） and interleukin-1β （IL-1β） in serum by ELISA.Oxygenation index （OI） was calculated.The animals were sacrificed and bronchoalveolar lavage fluid （BALF） was collected for determination of white blood cell count and protein concentrations.Lungs were removed for examination of pathological changes and ultrastructure and for determination of Toll-like receptor （TLR4） and phosphor-p38 mitogen activated protein kinase （p-p38MAPK） expression （by Western blot）.Results Compared with group S,PaO2 and OI were significantly decreased,PaCO2,protein concentrations in BALF,white blood cell count,and IL-6 and IL-1β concentrations in serum were increased,and TLR4 and p-p38MAPK expression was up-regulated in THSR,P1 and P2 groups.Compared with group THSR,PaO2 and OI were significantly increased,PaCO2,protein concentrations in BALF,white blood cell count,and IL-6 and IL-lβ concentrations in serum were decreased,TLR4 and p-p38MAPK expression was down-regulated in P1 and P2 groups.No significant differences were found in the parameters mentioned above between P1 and P2 groups.Conclusion PHC can mitigate acute lung injury induced by blunt chest trauma-hemorrhagic shock and resuscitation in rats,and inhibited activation of TLR4/ p38MAPK signaling pathway and attenuated inflammatory responses are involved in the mechanism.