线粒体损伤在脓毒症大鼠心肌细胞凋亡中的作用  

Role of damaged mitochondria in cardiocyte apoptosis in septic rats

作　　者：李莉[1] 严静[1] 陈昌勤[1] 龚仕金[1] 戴海文[1] 虞意华[1] 蔡国龙[1] 陈进[1] 许强宏[1] 

机构地区：[1]浙江医院重症医学科,杭州310013

出　　处：《中华急诊医学杂志》2012年第11期1221-1225,共5页Chinese Journal of Emergency Medicine

基　　金：国家自然科学基金面上项目（81171784）;浙江省自然科学基金（Z2100237,Y2110801）;浙江省医药卫生科学研究基金计划项目（2010KYB017）

摘　　要：【摘要】目的探讨线粒体损伤在脓毒症大鼠心肌细胞凋亡中的作用及其可能机制。方法72只SD大鼠随机（随机数字法）分为2组：（1）阴性对照组18只，腹腔注射无菌生理盐水；（2）脓毒症组，按大肠杆菌内毒素注射后6、12、24h分为3个亚组，各18只。取心脏组织，光镜和电镜下观察组织病理学和超微结构的变化，TUNEL法原位检测心肌细胞凋亡并计算凋亡指数，免疫印迹法检测核转录因子-κB（NF-κB）p65的表达，黄嘌呤氧化酶法测定线粒体超氧化物歧化酶（SOD）活性，比色法检测线粒体还原型谷胱甘肽（GPx）活性，硫代巴比妥酸法测定线粒体脂质过氧化产物丙二醛（MDA）含量，OxyBlot TMas蛋白氧化检测试剂盒观察线粒体蛋白氧化。结果脓毒症大鼠心肌有炎症细胞浸润，细胞水肿及空泡形成，并且在24h最明显；心肌细胞凋亡指数和核蛋白NF-κBp65活化均显著增加（P〈0．05）。脓毒症大鼠心肌线粒体损伤明显，至24h病变最严重，线粒体膜破碎，线粒体嵴消失，大量空泡形成。脓毒症大鼠心肌线粒体抗氧化酶SOD和GPx活性显著下降（均P〈0．05），线粒体脂质过氧化和蛋白氧化均显著增加（均P〈0．05），并呈时间依赖性。结论线粒体损伤在脓毒症心肌细胞凋亡中发挥重要作用，其作用机制可能与线粒体抗氧化物酶活性降低，活性氧产生过多和聚集有关。Objective To investigate the role of damaged mitochondria in cardiac cell apoptosis in septic rats and the possible mechanism involved. Methods Seventy-two Sprague-Dawley rats were randomly （random number） divided into negative control group （n = 18 ） and septic group （further divided into three groups as per rats sacrificed 6 h, 12 h, and 24 h after emlotoxin injection intra-peritoneally, n = 18）. The hearts of rats were taken. The changes of cardiac morphology were observed under light microscope and scanning electron microscope. Cell apoptosis in situ were examined by using terminal transferase - mediated dUTP nick end-labeling assay and nuclear factor-kappa B （NF-κB） activation in myocardium was detected by using Western blotting to estimate myocardial cell apoptosis. Mitochondrial lipid and protein oxidation were measured to assess oxidative stress, and mitoehondrial superoxide dismutase （SOD） and glutathione peroxidase （GPx） activities were determined to estimate antioxidant defense. Results Septic induced inflammatory cells infiltration, myocardium degeneration and effusion in a time-dependent manner. A remarkable expansion of capillaries could be observed in the hearts of infected rats at post-challenge of 24 h.Compared with sham-treated rats, the percentage of apoptosis increased in a time-dependent manner in the hearts of infected rats at 6 h, 12 h, 24 h of post-injection （P 〈0. 05）. The concentration of NF-κB p65 in the cytosol decreased gradually and increased in the nucleus during sepsis in a time-dependent manner （P 〈 0. 05）, indicating that septic challenge provoked progressive activation of NF-κB. Mitochondrial cristae disappeared in 6 h of challenge, and significant mitochondrial cristae disappearance, vacuolization, and rupture of mitochondria membrane became markedly obvious 12 and 24 h later. Both SOD and GPx activities decreased, while mitochondrial lipid and protein oxidation increased in a time-dependent manner after 6-24 h of challenge （P 〈 0. 05�

关 键 词：脓毒症 心肌损伤 细胞凋亡 线粒体 核转录因子-ΚB 

分 类 号：R285.5[医药卫生—中药学]