鼠肝缺血再灌注后肺组织ERK1/2通路活性变化及褪黑素的影响  

Changes of the activity of ERK1/2 signaling pathway in lung after total hepatic ischemia-reperfusion in rats and effects of melatonin

作　　者：姜春玲[1] 刘岩[2] 王金兰[2] 咸云淑[1] 张卫星[1] 

机构地区：[1]北京大学深圳医院,广东深圳518036 [2]吉林大学中日联谊医院

出　　处：《中国实验诊断学》2011年第2期194-198,共5页Chinese Journal of Laboratory Diagnosis

摘　　要：目的探讨大鼠全肝缺血再灌注后肺组织损伤、修复过程中ERK1/2信号通路活性的动态变化与意义,以及褪黑素对该信号通路的影响。方法本实验将分成两部分完成。第一部分,36只SD大鼠随机分成6组(n=6):①缺血前组;②再灌注0.5 h组;③再灌注3 h组;④再灌注6 h组;⑤再灌注12 h组;⑥再灌注24 h组。阻断肝门30 min后开放血流,建立大鼠全肝缺血再灌注模型。分别于缺血前5 min、再灌注0.5 h、3 h、6 h、12 h、24 h处死动物取肺,检测ERK1/2和p-ERK1/2表达、细胞凋亡、PCNA表达及肺组织病理学变化,观察肝缺血再灌注后肺组织ERK1/2信号通路活性的动态变化及其与细胞增殖、凋亡的关系。第二部分,将12只SD大鼠随机分成2组(n=6):褪黑素组与基质对照组,依上述方法制备全肝缺血再灌注模型,分别于全肝缺血前15 min和再灌注前10 min静脉注射0.5%褪黑素溶液10 mg/kg或相同剂量的溶剂,于再灌注3 h处死动物取肺,检测前述相同参数,观察褪黑素的作用。结果 (1)与缺血前相比,全肝缺血再灌注后肺组织p-ERK/ERK比值与PCNA阳性指数均于再灌注0.5 h显著降低,此后逐渐增高;细胞凋亡指数则于再灌注0.5 h显著增高,后逐渐上升,再灌注6 h达最高,后又逐渐下降;肺组织病理于再灌注0.5 h即出现损伤改变,后逐渐加重,再灌注3 h最重,此后逐渐恢复。(2)双变量相关分析显示:p-ERK/ERK比值与PCNA阳性指数成正相关(r=0.85,P<0.01);与凋亡指数呈负相关(r=-0.38,P<0.05)。(3)褪黑素组与基质对照组比较,p-ERK/ERK比值显著增加,细胞凋亡指数显著降低,病理学改变减轻,但PCNA阳性指数无明显变化。结论全肝缺血再灌注后肺组织损伤、修复过程中,ERK1/2信号通路活性呈先抑制后激活的变化方式,该通路可能通过抑制凋亡、促进增殖在损伤肺组织自身修复过程中发挥积极作用。褪黑素可激活ERK1/2信号通路,并可能由此减轻肝缺血再灌注后�Objective To explore the dynamic changes of the activity of extracellular signal-regulated kinases 1/2（ERK1/2） signaling pathway and its significance in lung injury and repair after total hepatic ischemia –reperfusion（I/R） of rats,and melatonin＇s effects on this pathway.Methods This study was divided into 2 parts.In the first part,36 healthy male SD rats weighing 250-300 g were randomly divided into 6 groups（n=6）：①pre-ischemia group,②reperfusion 0.5 h group,③reperfusion 3 h group,④reperfusion 6 h group,⑤reperfusion 12 h group,⑥reperfusion 24 h group.Total hepatic I/R was produced by occlusion of hepatic helium for 30 minutes,and the occlusion was then released for reperfusion.The animals were killed at 5 minutes prior to ischemia and 0.5 h,3 h,6 h,12 h,24 h of reperfusion,and the lung tissue was taken for determation of ERK1/2,pERK1/2 protein expression,apoptotic cells,PCNA protein expression and histological examination,to observe the dynamic changes of the activity of ERK1/2 signaling pathway and its relationship with cell proliferation and apoptosis.In the second part,12 healthy male SD rats weighing 250-300 g were randomly divided into 2 groups（n=6）：melatonin group and vehicle group.Melatonin（0.5%,10 mg·kg-1）or vehicle of the same volume was injected via femoral vein 15 min before ischemia and 10 min before reperfusion,the animals were killed at 3 h of reperfusion,and the lung tissue was taken to determine the same parameters to observed the effects of melatonin.Results（1）Compared with that in pre-ischemia group,the p-ERK/ERK ratio and PCNA-positive index were both decreased at 0.5 h of reperfusion,and then were increased gradually in the lung.While the apoptotic index was increased at 0.5 h of reperfusion and became higher gradually,which reached the peak at 6 h of reperfusion,then decreased slowly after that.Histological examination revealed that the lung was injured at 0.5 h of reperfusion,then worsened gradually,which reached the peak at 3 h of reperfusion and

关 键 词：褪黑素 缺血再灌注 肺损伤 细胞外信号调节激酶1/2 凋亡 

分 类 号：R363[医药卫生—病理学]