Shaposhnikov J D, Kisselev O I
Neoplasma. 1978;25(1):3-12.
Rat and mouse liver mitochondria, when centrifuged in a sucrose density gradient (25--50%, w/w), showed the presence of heavy (H) and light (L) subfractions with buoyant densities 1.185 and 1.170--1.165 g/ml, respectively. Mild treatment with digitonin or EDTA (30 mM) shifted H-subfraction of mitochondria into the lighter zone of the gradient and as a result of this the mitochondria were distributed as a homogenous band with buoyant density 1.170--1.165 g/ml. Mitochondria isolated from both MD hepatoma and Zajdela rat hepatoma were characterized by a homogenous banding with buoyant density 1.160--1.165 g/ml. Regarding to this, the content and patterns of polyribosomes bound to outer membranes of mouse tumor mitochondria were studied. Analysis of polyribosomes as well as the results of RNA polyacrylamide gel electrophoresis indicate that the content of these polyribosomes in tumor mitochondria is less than that in normal liver ones. However, the decrease of cancer cell membrane-bound polyribosomes cannot account for the differences in buoyant densities of mitochondria from normal and tumor tissues.
大鼠和小鼠的肝线粒体在蔗糖密度梯度（25%-50%，w/w）中离心后，显示出存在重（H）和轻（L）亚组分，其浮力密度分别为1.185 g/ml和1.170-1.165 g/ml。用洋地黄皂苷或EDTA（30 mM）进行温和处理会使线粒体的H亚组分转移到梯度较轻的区域，结果线粒体以浮力密度为1.170-1.165 g/ml的均匀条带形式分布。从MD肝癌和Zajdela大鼠肝癌中分离出的线粒体的特征是具有浮力密度为1.160-1.165 g/ml的均匀条带。据此，对与小鼠肿瘤线粒体外膜结合的多核糖体的含量和模式进行了研究。多核糖体分析以及RNA聚丙烯酰胺凝胶电泳结果表明，肿瘤线粒体中这些多核糖体的含量低于正常肝线粒体中的含量。然而，癌细胞膜结合多核糖体的减少并不能解释正常组织和肿瘤组织中线粒体浮力密度的差异。
