肝缺血再灌注损伤后电解质变化对心肌细胞超微结构的影响

1、肝缺血再灌注损伤后电解质变化对心肌细胞超微结构的影响 08-10-21 14:18:00 编辑：studa20 作者：蒋俊丹， 郑晓春， 陈彦青， 吴晓丹， 黄风怡【关键词】 肝疾病；,肠；,缺血再灌注损伤；,肌细胞,心脏；,电解质；,显微镜检查,电子摘要: 目的观察大鼠肝门阻断后缺血再灌注（IR）损伤对心肌细胞超微结构的影响。方法 大鼠气管切开机械通气，监测肺动脉压（PAP）。72只大鼠随机分为对照组（A组）、肝血流阻断组（B组）及门静脉转流下肝血流阻断组(C组)。于IR前和IR后1，6 h取左心室前壁心肌组织数块。血气分析肝门阻断期间门脉血pH和电解质；光、电镜下观察心肌细胞形态学改变。结

2、果 与A组比较，B，C组IR后PAP显著升高（P0.05），但C组较B组更快恢复至阻断前水平。肝门阻断期间，B组pH降低显著（P0.05，）；K+较IR前升幅超过1倍（P0.01），IR后下降，但6 h时仍处于较高水平（P0.05）。电镜观察，A组心肌细胞超微结构正常；B组心肌细胞6 h可见线粒体水肿，心肌肌丝断裂，细胞间隙增大，部分心肌细胞可见坏死区域，结构崩解；C组IR后部分心肌肌丝模糊，线粒体肿胀，心肌细胞局灶性坏死。结论 肝门阻断后门脉内酸性物质和高钾血症直接抑制心肌收缩力，减少心排，肠道IR损伤是引起心肌细胞超微结构损害的主要因素。关键词: 肝疾病； 肠； 缺血再灌注损伤； 肌细胞，

3、心脏； 电解质； 显微镜检查，电子ABSTRACT: ObjectiveTo investigate the myocardial morphologic changes after hepatic portal occlusion(HPO) ischemareperfusion injury. Methods Rats were mechanical ventilated. The animals were randomly divided into 3 groups：(1)control group was shamoperated; (2)HPO group, the animals w

4、ere subjected to reperfusion after 60 min hepatic portal occlusion; (3)bypass group, HPO 60 min while bypassed by caudal lobe. The animals in each group were killed before reperfusion and the end of reperfusion 60 or 360 min. The hemodynamics and portal vein blood gas analysis were measured, the myo

5、cardial cell morphology were studied by optics and electron microscopy.Results Hemodynamics data in both B,C groups showed low cardiac output during HPO phase, and pulmonary artery pressure(PAP) was higher than group A after reperfusion（P0.05）, but in group C the PAP return to baseline was faster th

6、an group B（P0.05）. Compared with groups A and C, the portal vein pH in group B decreased significantly during HPO but immedially return after reperfusion, simultaneously the K+ remarkablely increased and lasted to 6 h; the Ca2+ decreased gradually（P0.05）. The electron microscopy showed the myocardia

7、l morphology in group A was normal, group C appeared myofilament broken ,mitochondrium swelling,and some cell focus necrosis. Group B was serious than group C, such as mitochondrium edema, there were myofilament and muscle rod broken, cell spaces increasing, and local necrosis or disintegration.Conc

8、lusion The ischemiareperfusion injury afer HPO may affected myocardial cell and inhibit cardiac contractibility. The interruption of bowel blood stream and reperfusion of intestinal metabolites may be the principal cause of myocardium damage.KEY WORDS: liver diseases; intertines; ischemia reperfusio

9、n injury; myocyes,cardiac; electrolytes; microscopy, electron肝移植和肝门阻断（hepatic portal occlusion，HPO）手术中肝脏缺血再灌注(ischemiareperfusion，IR)损伤是常见的病理生理表现，其中门静脉阻断后肠道IR损伤被认为是术后多脏器功能不全（MOSF）的引擎1，导致肝外多脏器功能损伤。笔者观察HPO后肝和肠道IR损伤对心肌细胞超微结构的影响。1 动物与方法1.1 动物分组 选取体质量200250 g成年SD雄性大鼠福建医科大学实验动物中心，合格证号SCXK(闽20040008)，术前禁食1

10、2 h。10%水合氯醛3 mL/kg腹腔麻醉，气管切开机械通气（TKR200A，江西特力小动物呼吸机）。肝素500 IU/kg静脉注射。常规消毒，腹部正中切口入腹，离断肝周韧带，中断肝脏侧支循环。经右侧颈外静脉将PE50导管置入后连接压力换能器（Datex多功能监测仪，芬兰），确认至肺动脉后固定导管并测定肺动脉压（PAP）。股动脉置管监测平均动脉压（MAP）和心率（HR）。灯烤保温，保持肛温3637 。 所有大鼠随机分3组：（1）对照组(A组，n=24)，经腹正中切口入腹，切断全部肝周韧带；不作肝血流的阻断。（2）肝血流阻断组（B组,n=24），Pringle法阻断肝十二指肠韧带，使包括尾叶在

11、内的全部肝叶完全缺血2，60 min后开放灌注，肝复流后切除尾叶(约占全肝5%)。（3）门静脉转流下肝血流阻断组（C组,n=24），参照文献3分别阻断肝左中叶及右叶肝蒂，保留尾叶血供作为门脉回流通道；60 min后灌注，肝复流后切除尾叶。每组各有8只大鼠分别于IR前、IR后1，6 h处死，取左心室前壁心肌组织数块。1.2 方法全程连续监测。以阻断前数值为基础值，并于各时间点取值3次求均值。处死前取门脉血1 mL送检血气分析（M3562A,德国Philips公司；测试条美国Irma Trutoint公司，批号139903）。冰面上操作,取左室前壁心肌组织数块，各1 mm1 mm1 mm，3%戊二醛1.5%多聚甲醛前固定，1%锇酸1.5%亚铁氰化钾后固定，酒精丙酮脱水，环氧树脂618包埋剂包埋；超薄切片80 nm，醋酸铀、枸橼酸铅染色，透射电镜(