右美托咪定与氙气改良的UW液对猪心脏死亡供肺的保护作用

Protective effects of modified UW solution with dexmedetomidine and xenon on swine lung for donation after cardiac death

目的探讨右美托咪定(Dexmedetomidine,DEX)与氙气(Xenon,Xe)添加改良的威斯康星大学保存液(university of Wisconsin solution,UW液)对猪心脏死亡器官捐献(donation after cardiac death,DCD)供肺的保护作用。方法4~6月龄雄性小香猪4只,体质量为13~17 kg,采用静推顺式阿曲库铵及停止供氧建立猪心脏停跳模型,待热缺血(warm ischemia,WI)1 h后取肺并将其切成薄片。其中部分切片被命名为WI组,剩余切片则置于N_(2)/DEX/Xe添加的4种UW液中4℃冷缺血(cold ischemia,CI)24 h,并分别命名为WI+CI+N_(2)组、WI+CI+DEX组、WI+CI+DEX+30%Xe组、WI+CI+DEX+50%Xe组。5组肺组织切片行HE染色及组织损伤评分;TUNEL法检测细胞凋亡;Western blot检测cleaved Caspase-3、谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)表达;免疫组化检测GPX4、高迁移率族蛋白1(high mobility group protein 1,HMGB1)表达。结果与WI组比较:HE染色显示各组肺泡结构均无明显破坏,肺水肿及炎症细胞浸润不明显,肺损伤评分无显著变化;WI+CI+N_(2)组TUNEL阳性细胞数、cleaved Caspase-3蛋白表达显著增加(P<0.05);各组肺组织GPX4蛋白表达无显著变化;WI+CI+N_(2)组HMGB1蛋白表达量显著增多(P<0.05)。与WI+CI+N_(2)组比较:WI+CI+DEX组、WI+CI+DEX+30%Xe组和WI+CI+DEX+50%Xe组的TUNEL阳性细胞数显著减少(P<0.001,P<0.05,P<0.05);WI+CI+DEX+30%Xe组HMGB1蛋白表达显著降低(P<0.01)。结论DEX单独或联合Xe添加改良的UW液可通过抑制细胞凋亡、下调HMGB1表达及细胞质内弥散对猪DCD供肺发挥更好的细胞保护效果。

ObjectiveTo explore the protective effects of dexmedetomidine(DEX)and xenon(Xe)modified university of Wisconsin solution(UW solution)in a pig model of lung donation after cardiac death(DCD).MethodsFour healthy male mini-musk pigs aged 4-6 months,weighing 13-17 kg,were subjected to cardiac arrest by cis-atracurium infusion and cessation of oxygen supply.After 1 h of warm ischemia(WI),the lungs were harvested and cut into thin slices.Some of the slices served as WI group,while the other slices were preserved in N_(2)/DEX/Xe added 4 types of UW solutions at 4℃for 24 h of cold ischemia(CI).These slices were divided into WI+CI+N_(2) group,WI+CI+DEX group,WI+CI+DEX+30%Xe group,and WI+CI+DEX+50%Xe group.The above 5 group of tissue slices were stained with HE for pathological score.Apoptosis of pulmonary cells were detected by TUNEL.Western blotting was used to detect the expression of cleaved Caspase-3 and glutathione peroxidase 4(GPX4).The expression of GPX4 and high mobility group protein 1(HMGB1)were assessed by immunohistochemical staining.ResultsCompared with the WI group,the histology of other groups showed no significant damage to alveolar structures.Pulmonary edema and inflammatory cell infiltration were not obvious.The injury score of lung had no significant change in lung tissues of all groups(P>0.05).Compared with the WI group,the number of TUNEL-positive cells and the protein level of cleaved Caspase-3 were increased in the WI+CI+N_(2) group(P<0.05).However,the protein level of GPX4 had no significant change in lung tissues of all groups.Compared with the WI group,the protein level of HMGB1 was elevated in the WI+CI+N_(2) group(P<0.05).Compared with the WI+CI+N_(2) group,the number of TUNEL-positive cells was significantly reduced in the WI+CI+DEX group,WI+CI+DEX+30%Xe group and WI+CI+DEX+50%Xe group(P<0.001,P<0.05,P<0.05,respectively).The protein level of HMGB1 was significantly reduced in the WI+CI+DEX+30%Xe group(P<0.01).ConclusionThe UW solution added with DEX alone or in combination with Xe can provide better cell protection on swine DCD lung through inhibiting cell apoptosis,down-regulating expression and restraining cytoplasmic translocation of HMGB1.