Mikhaĭlov V M, Kazakov V I, Komarov S A, Nilova V K, Shteĭn G I, Baranov V S
Institute of Cytology, Russian Academy of Sciences, St. Petersburg.
Tsitologiia. 1998;40(5):401-6.
DNA destruction and apoptosis of ventricular cardiomyocytes were studied using DMX and C57Bl10/J mice. According to our electron microscope observations the cardiomyocyte nuclei undergo chromatin condensation with the nuclear membrane folding. In cardiomyocytes with significant nuclear destruction, structural disturbances in the cytoplasm are also seen. The 0.5% agarose gel electrophoresis reveals DNA fragments, sized 64 kb and more, inside the total DNA of MDX mice myocardium. No kinds of DNA fragments are available inside samples of the total DNA of C57Bl mice myocardium. Swimming during 5 min induces formation of the same type of DNA fragments inside the total of DNA of C57Bl mice myocardium, which was registered after 2 and 22 hours of the experiment. The DNA fragments disappear from the total C57Bl mice myocardium DNA within 48 h after the stress. Trypan blue evokes formation of the same 64 kb fragments inside DNA of myocardium within 24 h after injection to C57Bl mice. Electrophoresis of the total DNA with 2% agarose gel or 5% PAAG revealed no DNA samples analysed during this study. The authors conclude that DNA destruction and apoptosis characteristic features of MDX mice cardiomyocytes of mice, have a common mechanism of DNA degradation that works both after the stress of trypan blue action in case of C57Bl mice, and as a consequence of dystrophin absence in cardiomyocytes in the case of MDX mice.
使用DMX和C57Bl10/J小鼠研究了心室心肌细胞的DNA破坏和凋亡。根据我们的电子显微镜观察，心肌细胞核发生染色质浓缩，核膜折叠。在核破坏明显的心肌细胞中，也可见细胞质的结构紊乱。0.5%琼脂糖凝胶电泳显示，MDX小鼠心肌总DNA中存在大小为64 kb及以上的DNA片段。C57Bl小鼠心肌总DNA样本中未发现任何种类的DNA片段。在C57Bl小鼠心肌总DNA中，游泳5分钟会诱导形成相同类型的DNA片段，这在实验2小时和22小时后被检测到。应激后48小时内，这些DNA片段从C57Bl小鼠心肌总DNA中消失。给C57Bl小鼠注射锥虫蓝后24小时内，锥虫蓝会在心肌DNA中诱导形成相同的64 kb片段。在本研究中，用2%琼脂糖凝胶或5%聚丙烯酰胺凝胶对总DNA进行电泳，未发现所分析的DNA样本。作者得出结论，MDX小鼠心肌细胞的DNA破坏和凋亡特征，具有共同的DNA降解机制，该机制在C57Bl小鼠受到锥虫蓝作用的应激后起作用，在MDX小鼠中则是由于心肌细胞中缺乏肌营养不良蛋白所致。
