大鼠肝缺血再灌注后肺细胞凋亡及七氟醚对细胞凋亡及 NF-κBp65的影响

摘要

目的：探讨七氟醚预处理对大鼠肝缺血再灌注后肺细胞凋亡的影响。方法24只Wister大鼠随机分为3组（n＝8）：假手术组，缺血再灌注组，七氟醚组，阻断肝门30 min后建立大鼠70％肝缺血再灌注模型。假手术组（ S组）仅游离肝门，但不阻断；肝缺血再灌注组（ IR组）采用阻断肝门30 min，再灌注1 h的方法制备大鼠肝缺血再灌注损伤模型；七氟醚预处理组（ SP组）吸入2．1％七氟醚30 min，停止吸入10 min后制备肝缺血再灌注模型。于再灌注1 h时处死动物，留取肺组织，测定湿／干重比（ W／D比），采用比色法检测超氧化物歧化酶（ SOD）活性及丙二醛（ MDA）含量，采用原位末端转移酶法（ TUNEL）检测细胞凋亡，计算细胞凋亡指数（ AI），采用Western blot法测定核蛋白NF-κBp65表达，光镜下观察肺组织病理学结果。结果与S组比较，IR组和SP组再灌注各时点肺组织W／D比值、细胞凋亡指数（ AI）和NF-κB 活性水平及MDA含量均显著增高（均P＜0．05）；SOD活性显著降低（P＜0．05）；与IR组比较，SP组W／D比值、细胞凋亡指数（AI）、NF-κB表达水平与MDA含量显著降低（均P＜0．05）；而SOD活性显著增加（P＜0．05）；SP组肺组织损伤较IR组减轻。结论细胞凋亡可能在肝缺血再灌注肺损伤发生过程中具有重要意义；七氟醚对大鼠肝缺血再灌注后肺细胞凋亡具有抑制作用，其作用机制可能通过降低肺组织NF-κB的活性，从而清除自由基、抑制脂质过氧化有关。%Objective To explore the influences of sevoflurane pretreatment on apoptosis of rat lung cells after hepatic ischemia reperfusion. Methods Twenty-four Wister rats were randomized into 3 groups (n=8):sham-operation group, hepatic ischemia reperfusion group and sevoflurane group.After 30 min of hepatic portal occlusion, rat models with 70%hepatic ischemia and reperfusion were established.Porta hepatis was only separated but not blocked in the sham-operation group (group S);hepatic ischemia reperfusion rat model was established by 30 min of hepatic portal occlusion and 1 h of reperfusion in hepatic ischemia reperfusion group (group IR);In sevoflurane pretreatment group (group SP), the rats were inhaled with 2.1%of sevoflurane for 30 min, and then stopped.10 min later, hepatic ischemia reperfusion model was established. The animals were executed at 1h after reperfusion.The lung tissue was taken.Wet/dry weight ratio (W/D ratio) was determined.Colorimetry was adopted to determine activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA).Terminal-deoxynucleoitidyl transfer-ase mediated nick end labeling (TUNEL) was used to determine cell apoptosis.Cell apoptosis index (AI) was calculated.Western blot was used to determine expressions of NF-κBp65.Pathological results of lung tissue were observed under microscope.Results W/D ratios, AIs, NF-κB activity and MDA content of group IR and group SP at each time after reperfusion were significantly increased compared with group S (All P<0. 05);SOD activity was decreased significantly (P<0.05);W/D ratios, AIs, NF-κB activity and MDA content of group SP were significantly low-er than those of group IR (All P<0.05);and SOD activity was obviously increased (P<0.05);lung tissue injury of group SP was decreased compared with group IR.Conclusions Cell apoptosis may play an important role in lung tissue injury due to hepatic ischemia reperfusion. Sevoflurane has a certain inhibition on rat lung cell apoptosis after hepatic ischemia reperfusion, which may eliminate free radicals and inhibit lip-id peroxidation by reducing activity of NF-κB in lung tissue.