右美托咪定对肠缺血再灌注肺损伤中自噬与凋亡的影响  

The effect of dexmedetomidine on autophagy and apoptosis in intestinal ischemia reperfusion-induced lung injury

作　　者：解春艳[1] 李云峰[2] 梁江水[3] 肖金仿[1] 赵振龙[1] 李涛[2] 

机构地区：[1]南方医科大学南方医院麻醉科,广州510515 [2]湖南省郴州市第一人民医院重症医学科 [3]湖南省郴州市第一人民医院胸部肿瘤肺癌诊疗中心

出　　处：《中华结核和呼吸杂志》2015年第10期761-764,共4页Chinese Journal of Tuberculosis and Respiratory Diseases

基　　金：国家自然科学基金（81500066）;郴州市第一人民医院优秀青年基金（N-2014-004）

摘　　要：目的 探讨右美托咪定对肠缺血再灌注后肺损伤中细胞自噬与凋亡的影响.方法 按随机数字表法将24只SD大鼠分为对照组、缺血再灌注组（I/R组）、低剂量右美托咪定组（D1组）和高剂量右美托咪定组（D2）,每组6只.采用夹闭肠系膜上动脉60 min,再灌注12 h制备肠缺血再灌注后肺损伤模型.D1及D2组分别于夹闭前10 min给予右美托咪定1和5μg/kg,对照组及I/R组给予等量生理盐水.采用HE染色观察肺部病理变化;Westem blot法检测肺组织中微管相关蛋白轻链3（LC3）Ⅱ/I蛋白表达比值、Beclin-1蛋白、Bax及Bcl-2蛋白表达水平;TUNEL法检测肺组织细胞凋亡情况并计数;免疫组织化学法测定肺组织半胱氨酸天门冬氨酸蛋白酶3（caspase-3）活性.结果 与对照组比较,I/R组肺组织可见大量中性粒细胞浸润,肺泡壁增厚,而D2组仅少量炎症细胞浸润;与对照组比较,I/R组TUNEL阳性细胞[（69±8）个/视野]、LC3Ⅱ/I比值（57±8）、Beclin-1（488％±45％）及Bax（358％±37％）蛋白表达显著增加（均P＜0.05）,Bcl-2（39％±5％）蛋白表达下降（P＜0.05）;与I/R组比较,D2组中TUNEL阳性细胞[（32±5）个/视野]、LC3Ⅱ/I比值（27±4）、beelin-1 （285％±41％）及Bax（181％±25％）明显下降（均P＜0.05）,Bcl-2（91％±9％）蛋白表达明显增加（P＜0.05）;免疫组织化学示I/R组肺组织caspase-3活性较对照组明显增加,D2组肺组织caspase-3活性较I/R组明显降低.结论 肠缺血再灌注肺损伤中细胞自噬与凋亡被激活,而右美托咪定可通过抑制细胞自噬与凋亡,显著改善肠缺血再灌注介导的肺损伤.Objective To investigate the protective effects of dexmedetomidine against autophagy and apoptosis in intestinal ischemia reperfusion（I/R）-induced lung injury.Methods Twenty-four SD rats were randomly and equally divided into 4 groups according to the random number table：control group,L/R group,small dose of dexmedetomidine（D1） group and large dose of dexmedetomidine（D2） group.The model of lung injury was induced by occlusion of the superior mesenteric artery for 60 min followed by 12 h reperfusion.Rats in D1 and D2 groups received intravenous injection of dexmedetomidine at dose of 1 μg/kg and 5 μg/kg respectively.Rats in control and I/R groups were given same volume of normal saline.Pathological changes were detected by hematoxylin-eosin（HE） staining.The microtubule-associated protein 1 light chain 3 （LC3） Ⅱ / I ratio,Beclin-1,Bax and Bcl-2 expression were measured by Western blot.Cell apoptosis was assayed by terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL）,while caspase-3 activity was evaluated by immunohistochemistry.Results Significant infiltration of neutrophils and thickened alveolar walls were observed in the I/R group compared to the control group,which were improved by dexmedetomidine （5 μg/kg）treatment.Compared to the control group,the apoptosis cells [（69 ± 8） cells/field],LC3 Ⅱ / Ⅰ ratio （57 ± 8）,Beclin-1 （487％ ± 45％） and Bax （358 ％ ± 37％） expression were markedly increased（P ＜ 0.05）,while Bcl-2 （39％ ± 5％） expression was decreased （P ＜ 0.05）in the I/R group.Compared to the I/R group,the apoptosis cells [（32 ± 5） cells/field],LC3 Ⅱ/Ⅰ ratio （27 ± 4）,Beclin-1 （285 ％ ± 41％） and Bax （181％ ± 25 ％） expression were markedly reduced （P ＜ 0.05）,while Bcl-2 （91％ ± 9％） expression was increased （P ＜ 0.05） in the D2 group.Conclusions Autophagy and apoptosis were activated in intestinal I/R-induced lung injury.Dexmedetomidine ameliorated intestinal I/R-ind

关 键 词：再灌注损伤 右美托咪定 自噬 细胞凋亡 

分 类 号：R614[医药卫生—麻醉学]