七氟醚对失血性休克诱发猪脑损伤时NF-κB活化的影响

Effect of sevoflurane on activation of NF-KB during brain injury induced by hemorrhagic shock in pigs

目的评价七氟醚对失血性休克诱发猪脑损伤时NF-κB活化的影响。方法成年雄性巴马小型猪32头，6月龄，体重22～25 kg，采用随机数字表法分为4组（n＝8）：假手术组（Sham组）不放血，仅行双侧股动脉、颈内静脉穿刺术；失血性休克组（HS组）采用容量控制性放血法制备失血性休克模型；七氟醚预处理组（Sev-Pre组）吸入2%七氟醚30 min后制备失血性休克模型；七氟醚后处理组（Sev-Post组）于失血性休克模型制备成功即刻吸入2%七氟醚30 min。于造模前即刻（T0）、失血性休克30 、60 、90 、120 、180和240 min（T1～6）时，采集颈静脉血样，采用ELISA法检测血清IL-1β和TNF-α浓度。于失血性休克4 h时处死，取脑组织，采用HE染色法观察海马CA1区病理学结果；采用Western blot法测定海马CA1区核蛋白NF-κB表达水平。结果与Sham组比较，HS组、Sev-Pre组和Sev-Post组T2～6时血清IL-1β和TNF-α浓度升高，海马CA1区核蛋白NF-κB表达上调（P〈0.05）；与HS组比较，Sev-Pre组和Sev-Post组T3～6时血清IL-1β和TNF-α浓度降低，海马CA1区核蛋白NF-κB表达下调（P〈0.05）；Sev-Pre组和Sev-Post组各时点血清IL-1β、TNF-α浓度及海马CA1区核蛋白NF-κB表达比较差异无统计学意义（P〉0.05）。Sev-Pre组和Sev-Post组病理学损伤较HS组减轻。结论七氟醚减轻失血性休克猪脑损伤的机制可能与抑制NF-κB活化，减轻炎性反应有关。

Objective To evaluate the effect of sevoflurane on activation of nuclear factor kappa B （NF-κB） during brain injury induced by hemorrhagic shock （HS） in pigs. Methods Thirty-two adult male Bama miniature pigs, aged 6 months, weighing 22-25 kg, were divided into 4 groups （n=8 each） using a random number table： sham operation group （group Sham） , HS group, sevoflurane preconditioning group （group Sev-Pre） and sevoflurane postconditioning group （group Sev-Post）. The animals were anesthetized, and tracheostomized and mechanically ventilated. In group Sham, the bilateral femoral arteries and internal jugular veins were only cannulated. HS was induced by removing 40% of blood volume within 15 min （30 ml/kg） via the right femoral artery and maintaining at this level for 1 h before resuscitation in HS, Sev-Pre and Sev-Post groups. In group Sev-Pre, 2% sevoflurane was inhaled for 30 min, and then HS was induced. In group Sev-Post, 2% sevoflurane was inhaled for 30 min starting from the time point immediately after HS was induced. Immediately before establishment of the model and at 30, 60, 90, 120, 180 and 240 min of HS （T1_6） , blood samples from the jugular vein were collected for determination of serum interleukin-lbeta （IL-1β） and tumor necrosis factor-alpha （TNF-ct） concentrations by enzymelinked immunosorbent assay. At 4 h of HS, the rats were sacrificed, and brains were removed for micro-scopic examination of hippocampal CA1 region （using haematoxylin and eosin staining） and for determina- tion of the expression of NF-κB in nucleoprotein （by Western blot）. Results Compared with group Sham, the concentrations of serum IL-1β and TNF-α were significantly increased at T2-6, and the expression of NF-κB in nucleoprotein in hippocampal CA1 region was up-regulated in HS, Sev-Pre and Sev-Post groups （P〈0. 05）. Compared with group HS, the concentrations of serum IL-1β and TNF-α were significantly decreased at T3-6 , and the expression of NF-KB in nucleoprotein in hippocampal CA1 region was down-regulated in Sev-Pre and Sev-Post groups （P〈0.05）. There were no significant differences between group SevPre and group Sev-Post in concentrations of serum IL-1β and TNF-α and expression of NF-KB in nucleoprotein in hippocampal CA1 region （P〉0.05）. The pathologic changes were significantly attenuated in SevPre and Sev-Post groups as compared with group HS. Conclusion The mechanism by which sevoflurane attenuates brain injury induced by HS may be related to inhibition of NF-κB activation and reduction of inflammatory responses in pigs.