七氟烷对急性肺损伤大鼠肺功能和NF-κB/NLRP3炎性体通路的影响

Effects of sevoflurane on lung function and the NF-κB/NLRP3 inflammatory pathway in rats with acute lung injury

目的研究七氟烷对急性肺损伤大鼠肺功能及核因子-κB/核苷酸结合寡聚化结构域样受体蛋白3(NF-κB/NLRP3)通路的影响。方法将75只大鼠随机分为对照组、模型组及1.5%、2.0%、2.5%七氟烷组,每组15只。除对照组外,其余4组腹腔注射5 mg/kg脂多糖制备急性肺损伤模型,造模后1.5%、2.0%、2.5%七氟烷组分别自由吸入1.5%、2.0%、2.5%七氟烷60 min,对照组和模型组自由呼吸空气。比较5组大鼠一般情况、肺功能状况(气道阻力、动态肺顺应性、用力肺活量)、肺湿/干比值(W/D)、氧合指数[动脉血氧分压(PaO_(2))/吸入氧浓度(FiO_(2))]、肺组织病理变化、肺泡灌洗液中炎性因子水平[肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)、白介素-1β(IL-1β)],采用蛋白免疫印迹法检测并比较5组大鼠肺组织NF-κB、NLRP3、凋亡相关斑点样蛋白(ASC)、半胱氨酸天冬氨酸蛋白水解酶1(caspase-1)表达水平。结果脂多糖作用96 h后,对照组、模型组及1.5%、2.0%、2.5%七氟烷组大鼠生存率分别为100%(15/15)、60.00%(9/15)、66.67%(10/15)、80.00%(12/15)、73.33%(11/15),2.0%七氟烷能明显提高大鼠生存率。HE染色显示,模型组肺组织病理改变明显,包括大量炎性细胞浸润、肺泡壁增厚且肺泡血管阻塞等,相较于模型组,1.5%、2.0%、2.5%七氟烷组肺组织病理改变有程度不同的减轻,其中以2.0%七氟烷改善效果最佳。与对照组比较,模型组气道阻力、肺W/D、TNF-α、IL-1β、IL-6、NF-κB、NLRP3、ASC、caspase-1显著升高(P<0.05),动态肺顺应性、用力肺活量、PaO_(2)/FiO_(2)显著降低(P<0.05);与模型组比较,1.5%、2.0%、2.5%七氟烷组气道阻力、肺W/D、TNF-α、IL-1β、IL-6、NF-κB、NLRP3、ASC、caspase-1显著降低(P<0.05),动态肺顺应性、用力肺活量、PaO_(2)/FiO_(2)显著升高(P<0.05)。结论七氟烷对急性肺损伤大鼠肺功能具有保护作用,以2.0%七氟烷肺保护效果最佳,其机制可能与抑制NF-κB/NLRP3炎性体通路有关。

Objective To study the effects of sevoflurane on lung function and the nuclear factor-κB/nucleotide binding oligomerization domain like receptor protein 3(NF-κB/NLRP3)pathway in rats with acute lung injury.Methods A total of 75 rats were randomly divided into control group,model group,and 1.5%,2.0%,and 2.5%sevoflurane groups,with 15 rats in each group.Except for those in the control group,acute lung injury models were prepared by intraperitoneal injection of 5mg/kg lipopolysaccharide into the other groups.After modeling,rats in the 1.5%,2.0%,and 2.5%sevoflurane groups freely inhaled 1.5%,2.0%,and 2.5%sevoflurane for 60 minutes,respectively,while those in the control group and model group freely breathed air.General situation,lung function status(airway resistance,dynamic lung compliance,forced lung capacity),lung wet-to-dry ratio(W/D),oxygenation index(arterial partial pressure of oxygen[PaO_(2)]/inhalation oxygen concentration[FiO_(2)]),pathological changes in lung tissues,and levels of inflammatory factors in alveolar lavage fluid(tumor necrosis factor[TNF-α],interleukin-6[IL-6],interleukin-1β[IL-1β])were compared.Protein levels of NF-κB,NLRP3,ASC(apoptosis-associated speck-like protein containing a caspase recruitment domain),and caspase-1 in lung tissue of rats in each group were detected by Western blot.Results After 96 hours of lipopolysaccharide treatment,the survival rate of rats in the control group,model group,and 1.5%,2.0%,and 2.5%sevoflurane groups was 100%(15/15),60.00%(9/15),66.67%(10/15),80.00%(12/15),and 73.33%(11/15),respectively.Induction of 2.0%sevoflurane significantly improved the survival rate of rats.H&E staining showed pronounced pathological changes in the lung tissue of the model group,including a large number of inflammatory cell infiltration,thickening of alveolar walls,and obstruction of alveolar blood vessels.Compared with those of the model group,pathological changes in the lung tissue of rats in the 1.5%,2.0%,and 2.5%sevoflurane groups were alleviated to varying degrees,especially in the 2.0%sevoflurane group.Compared with those of the control group,the model group showed significantly increased airway resistance,lung W/D,and expression levels of TNF-α,IL-1β,IL-6,NF-κB,NLRP3,ASC,and caspase-1(P<0.05),while dynamic lung compliance,forced lung capacity,and PaO_(2)/FiO_(2) significantly decreased(P<0.05).Compared with those of the model group,the 1.5%,2.0%,and 2.5%sevoflurane groups showed significantly lower airway resistance,lung W/D and expression levels of TNF-α,IL-1β,IL-6,NF-κB,NLRP3,ASC,and caspase-1(P<0.05),while dynamic lung compliance,forced lung capacity,and PaO_(2)/FiO_(2) were significantly higher(P<0.05).Conclusion Heptaflurane has a protective effect on lung function in rats with acute lung injury.The induction of 2.0%heptaflurane has the best lung protection effect by inhibiting the NF-κB/NLRP3 inflammatory pathway.