Lemeshko Victor V, Solano Sigifredo, López Luis F, Rendón Dairo A, Ghafourifar Pedram, Gómez Luis A
Science Department, School of Physics, National University of Colombia, Medellin Branch, AA3840 Medellin, Colombia.
Arch Biochem Biophys. 2003 Apr 15;412(2):176-85. doi: 10.1016/s0003-9861(03)00034-1.
It has been reported that dextrans diminish the intermembrane space of mitochondria, increase the number of contact sites between the inner and the outer mitochondrial membranes, decrease the outer membrane permeability to adenosine 5(')-diphosphate, and change the kinetic properties of mitochondrial kinases. In the present work the influence of dextran M40 (5% w/v) on the oxidoreductase activities of the inner and outer membranes of mitochondria, the interaction of cytochrome c with mitochondrial membranes, and the light scattering by rat liver mitochondria were studied. No influence of dextran on the release of cytochrome c from mitochondria or its interaction with mitochondrial membranes was observed. Decreases in the NADH-oxidase (to 80+/-2% of the control), NADH-cytochrome c reductase (to 26+/-2%), succinate-cytochrome c reductase (to 70+/-5%), and NADH-ferricyanide reductase (to 75+/-3%) activities induced by dextran, which may be due to the mitochondrial aggregation, were observed. The formation of aggregates was registered by light scattering, confirmed by light microscopy, and explained within the framework of the Gouy-Chapman theory of the electrical double layer. The observed mitochondrial aggregation seems to be useful also for understanding the mechanisms of mitochondrial condensation and perinuclear clustering during apoptosis.
据报道，右旋糖酐可减小线粒体的膜间隙，增加线粒体内外膜之间接触位点的数量，降低外膜对腺苷5′-二磷酸的通透性，并改变线粒体激酶的动力学特性。在本研究中，研究了右旋糖酐M40（5% w/v）对线粒体内膜和外膜氧化还原酶活性、细胞色素c与线粒体膜的相互作用以及大鼠肝线粒体光散射的影响。未观察到右旋糖酐对细胞色素c从线粒体释放或其与线粒体膜相互作用的影响。观察到右旋糖酐诱导NADH氧化酶活性（降至对照的80±2%）、NADH-细胞色素c还原酶活性（降至对照的26±2%）、琥珀酸-细胞色素c还原酶活性（降至对照的70±5%）和NADH-铁氰化物还原酶活性（降至对照的75±3%）降低，这可能是由于线粒体聚集所致。通过光散射记录了聚集体的形成，通过光学显微镜证实，并在 Gouy-Chapman 双电层理论框架内进行了解释。观察到的线粒体聚集似乎也有助于理解细胞凋亡过程中线粒体浓缩和核周聚集的机制。
