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目的:观察心脏骤停（cardiac arrest, CA）大鼠自主循环恢复（return of spontaneous circulation, ROSC）后线粒体分裂、融合在心脏中的变化，探讨线粒体分裂和融合在ROSC后心肌损伤中的作用。方法:将健康雄性SD大鼠按随机数字法分为复苏后（post-resuscitation, PR）4 h组、PR 24 h组、PR 72 h组及假手术（Sham）组，Sham组6只，其余每组12只。以窒息法诱导建立大鼠CA模型，CA 6 min后进行心肺复苏（cardiopulmonary resuscitation, CPR）。各组动物分别在ROSC后4 h、24 h、72 h行Western blot检测线粒体Drp1、Fis1、Mfn1及Opa1的蛋白表达，行RT-PCR法检测Drp1、Fis1、Mfn1及Opa1的mRNA表达，检测心肌组织ATP水平及线粒体呼吸功能，并通过光镜观察心肌组织病理学结构。定量资料多组均数比较采用单因素方差分析，组间两两比较采用LSD-n t检验。n 结果:PR 4 h和PR 24 h组，Drp1和Fis1的蛋白及mRNA表达升高，Mfn1和Opa1的蛋白及mRNA表达下降，与Sham组比较差异有统计学意义（均n P0.05）；与Sham组相比，PR 4 h和PR 24 h组心肌组织ATP水平[（8.57±0.44） nmol/g protein n vs. （4.53±0.76） nmol/g protein，（8.57±0.44） nmol/g protein n vs.（5.58±0.58） nmol/g protein]及线粒体呼吸控制率[（3.45±0.32） n vs. （2.47±0.38），（3.45±0.32） n vs. （2.97±0.24）]下降明显，差异有统计学意义（均n P0.05）。PR 4 h组可见心肌组织病理损伤明显，PR 72 h组心肌组织病理损伤明显改善。n 结论:CA/ROSC后早期的线粒体分裂融合失衡参与了复苏后心肌损伤的病理过程，其机制可能与线粒体功能受损有关。“,”Objective:To investigate the dynamic changes of mitochondrial fission and fusion in the heart of cardiac arrest (CA) rats after return of spontaneous circulation (ROSC), and to explore the role of mitochondrial fission and fusion in the myocardial injury after ROSC.Methods:Healthy male SD rats were randomly random number assigned into the post-resuscitation (PR) 4 h (n n=12), PR 24 h (n n=12), PR 72 h (n n=12), and sham groups (n n=6). The rat CA model was induced by asphyxia, and cardiopulmonary resuscitation (CPR) was performed 6 min after CA. The protein expressions of mitochondrial Drp1, Fis1, Mfn1, and Opa1 were determined by Western blot in each group at 4, 24 and 72 h after ROSC. The mRNA expressions of Drp1, Fis1, Mfn1, and Opa1 were determined by RT-PCR. Myocardial ATP content and mitochondrial respiratory function were measured. The histopathologic changes of myocardial tissue were observed under light microscope. One-way analysis of variance (ANOVA) was use to compare quantitative data, and LSD-n t test was used for comparison between groups.n Results:Compared with the sham group, the protein and mRNA expressions of Drp1 and Fis1 were increased (all n P<0.05) and the protein and mRNA expressions of Mfn1 and Opa1 were decreased (all n P0.05). Compared with the sham group, the levels of ATP content [(4.53±0.76) nmol/g protein n vs. (8.57±0.44) nmol/g protein and (5.58±0.58) nmol/g protein n vs. (8.57±0.44) nmol/g protein] and mitochondrial respiratory control rate [(2.47±0.38) n vs. (3.45±0.32) and (2.97±0.24) n vs. (3.45±0.32)] were obviously decreased in the PR 4 h and PR 24 h groups (all n P0.05). The pathological damage of myocardial tissue was obvious in the PR 4 h group, and was improved significantly in the PR 72 h group.n Conclusions:The imbalance of mitochondrial fission and fusion is probably involved in the pathological process of myocardial injury after ROSC, which may be related to mitochondrial dysfunction.