Duthie G G, Shipley A, Smith P J
Rowett Research Institute, Aberdeen, Scotland, U.K.
Free Radic Res. 1994 May;20(5):307-13. doi: 10.3109/10715769409145630.
A self-referencing and non-invasive Ca(2+)-sensitive vibrating electrode was used to assess the effects of hydrogen peroxide-induced oxidative challenges on the efflux and influx of calcium across the plasma membrane of single nerve cells cultured from abdominal ganglion of Aplysia californica. A reduced net efflux of Ca2+ from the cell soma occurred immediately after the addition of hydrogen peroxide (0.0025 mM, 0.005 mM or 0.01 mM) to the culture medium, indicating damage to the cell membrane or Ca2+ transport mechanism. There then followed a marked efflux, the extent and duration of which was related to the concentration of hydrogen peroxide used and which may reflect compensatory activity by the Ca2+ regulatory mechanisms in the plasmalemma. No morphological changes were observed in cells challenged with 0.0025 mM hydrogen peroxide and the enhanced rate of Ca2+ efflux rapidly decreased to pre-exposure values. Sustained and enhanced Ca2+ effluxes from those cells exposed to 0.005 mM or 0.01 mM hydrogen peroxide were also consistent with regulatory pumping of Ca2+ out of the cell although contraction and blebbing of neurites and swelling of the soma may indicate that a proportion of the efflux arose from release of Ca2+ from disrupted intracellular stores. The vibrating electrode is a useful additional technique for the study of the pathogenesis of neurological conditions, as ionic fluxes across single nerve cells exposed to physiologically-relevant concentrations of free radicals can be monitored non-invasively for prolonged periods.
使用一种自参考且非侵入性的钙敏感振动电极，来评估过氧化氢诱导的氧化应激对从加州海兔腹神经节培养的单个神经细胞质膜上钙的外流和内流的影响。向培养基中添加过氧化氢（0.0025 mM、0.005 mM或0.01 mM）后，细胞体中钙离子的净外流立即减少，这表明细胞膜或钙转运机制受到了损伤。随后出现了明显的外流，其程度和持续时间与所用过氧化氢的浓度有关，这可能反映了质膜中钙调节机制的代偿活性。在用0.0025 mM过氧化氢处理的细胞中未观察到形态变化，并且钙离子外流增强的速率迅速降至暴露前的值。暴露于0.005 mM或0.01 mM过氧化氢的细胞中持续且增强的钙离子外流也与钙离子从细胞中被调节泵出一致，尽管神经突的收缩和起泡以及细胞体的肿胀可能表明一部分外流是由于细胞内储存的钙离子释放所致。振动电极是研究神经疾病发病机制的一种有用的辅助技术，因为可以长时间非侵入性地监测暴露于生理相关浓度自由基的单个神经细胞上的离子通量。
