Olson J E, Fleischhacker D, Murray W B, Holtzman D
Department of Emergency Medicine, Wright State University School of Medicine, Dayton, Ohio 45401.
Glia. 1990;3(5):405-12. doi: 10.1002/glia.440030512.
Astrocytes from primary culture were exposed to conditions that affect intracellular and extracellular Ca2+ concentrations. Astrocyte cell volume was increased approximately 16% after a 30 min exposure to isoosmotic phosphate-buffered saline (PBS) containing the Ca2+ buffer EDTA. Cell volume returned to control values within 30 min of resuspension in normal PBS. Cellular calcium content was not affected by these treatments; however, the recovery of normal cell volume following EDTA exposure was inhibited by 0.1-1.0 mM quinine HCl in a dose-dependent fashion suggesting that a potassium channel controlled by the intracellular Ca2+ concentration is important in this volume response. Intracellular accumulation of an exogenous Ca2+ buffer, BAPTA, also produced cell swelling that persisted following resuspension in normal PBS. Lowering the extracellular Ca2+ concentration with EDTA enhanced the swelling of BAPTA-loaded cells. These data suggest that conditions leading to a decrease in free intracellular Ca2+ concentration may influence astrocyte volume by a mechanism similar to that described in other cell types.
将原代培养的星形胶质细胞置于影响细胞内和细胞外钙离子浓度的条件下。在暴露于含有钙离子缓冲剂乙二胺四乙酸（EDTA）的等渗磷酸盐缓冲盐水（PBS）30分钟后，星形胶质细胞的细胞体积增加了约16%。在重新悬浮于正常PBS中30分钟内，细胞体积恢复到对照值。细胞内钙含量不受这些处理的影响；然而，暴露于EDTA后正常细胞体积的恢复受到0.1 - 1.0 mM盐酸奎宁的剂量依赖性抑制，这表明由细胞内钙离子浓度控制的钾通道在这种体积反应中很重要。外源性钙离子缓冲剂1,2-双（2-氨基苯氧基）乙烷-N,N,N',N'-四乙酸（BAPTA）在细胞内的积累也会导致细胞肿胀，在重新悬浮于正常PBS后肿胀持续存在。用EDTA降低细胞外钙离子浓度会增强加载BAPTA的细胞的肿胀。这些数据表明，导致细胞内游离钙离子浓度降低的条件可能通过与其他细胞类型中描述的类似机制影响星形胶质细胞体积。
