Structural differences in two biochemically defined populations of cardiac mitochondria.
Structural differences in two biochemically defined populations of cardiac mitochondria.
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DOI：
10.1152/ajpheart.00866.2004
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发表时间：
2005-04
期刊：
影响因子：
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通讯作者：
A. Riva;B. Tandler;F. Loffredo;Edwin J. Vazquez;C. Hoppel
中科院分区：
文献类型：
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作者：
A. Riva;B. Tandler;F. Loffredo;Edwin J. Vazquez;C. Hoppel
为了确定是否有两个拓扑分离，生化定义的线粒体种群在大鼠心肌细胞的结构差异，这些细胞器的内部进行了检查，通过高分辨率扫描电子显微镜。基于159个原位肌膜下线粒体（SSM，即，那些直接邻接肌膜的细胞器），这些细胞器主要具有片状嵴（77%），而原位原纤维间线粒体（IFM，即，位于肌原纤维之间的肌纤维（n = 300）主要为管状（55%）或管状和片状混合（24%）。孤立的SSM（n = 374），类似于他们在原位的同行，主要是片状嵴（75%）。嵴类型的比例在孤立的IFM（n = 337）已被改变，只有20%的这些细胞器保留完全管状嵴，而58%的混合;后者，片状嵴占主导地位。这一发现表明，与SSM相反，IFM中的嵴在结构上是塑性的，在隔离期间发生变化。这些对超过1,000个细胞器的观察为两种心肌线粒体群体之间的明确差异提供了第一个定量形态学证据。
To determine whether there are structural differences in two topologically separated, biochemically defined mitochondrial populations in rat heart myocytes, the interior of these organelles was examined by high-resolution scanning electron microscopy. On the basis of a count of 159 in situ subsarcolemmal mitochondria (SSM, i.e., those that directly abut the sarcolemma), these organelles possess mainly lamelliform cristae (77%), whereas the cristae in in situ interfibrillar mitochondria (IFM, i.e., those situated between the myofibrils, n = 300) are mainly tubular (55%) or a mixture of tubular and lamelliform (24%). Isolated SSM (n = 374), similar to their in situ counterparts, have predominantly lamelliform cristae (75%). The proportions of crista types in isolated IFM (n = 337) have been altered, with only 20% of these organelles retaining exclusively tubular cristae, whereas 58% are mixed; of the latter, lamelliform cristae predominate. This finding suggests that, in contrast to SSM, the cristae in IFM are structurally plastic, changing during isolation. These observations on >1,000 organelles provide the first quantitative morphological evidence for definitive differences between the two populations of cardiac mitochondria.