Dominant role of mitochondria in clearance of large Ca2+ loads from rat adrenal chromaffin cells
Dominant role of mitochondria in clearance of large Ca2+ loads from rat adrenal chromaffin cells
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DOI：
10.1016/s0896-6273(00)80038-0
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发表时间：
1996-01-01
期刊：
影响因子：
16.2
通讯作者：
Hille, B
中科院分区：
文献类型：
--
作者：
Herrington, J;Park, YB;Hille, B
应用全细胞膜片钳技术和indo-1Ca ~（2+）光度法研究了肾上腺嗜铬细胞内Ca ~（2+）经电压依赖性Ca ~（2+）通道内流后的胞浆Ca ~（2+）清除。我们使用下列药物的组合，通过几种机制分离出Ca-c（2+）清除率（预期目标）：Li+或TEA取代Na+（Na+-Ca 2+交换），在去极化后施加1 mM La 3 +（Na+-Ca 2+交换和质膜Ca 2 +-ATP酶），1 μ M毒胡萝卜素（泵入网状储存器）和2 μ M羰基氰化物间氯苯腙（摄取到线粒体中）。值得注意的是，当[Ca 2 +]（c）升高到500 nM以上时，线粒体对Ca-c（2+）的清除率超过了Na+-Ca 2+交换或质膜和网状膜的Ca 2+泵的清除率。随着[Ca 2 +]（c）再次下降，Ca 2+重新从线粒体中出现，延长了最终恢复到基础水平的时间。
Cytosolic Ca2+ (Ca-c(2+)) clearance from adrenal chromaffin cells was studied by whole-cell patch clamp and indo-1 Ca2+ photometry after influx of Ca2+ through voltage-dependent Ca2+ channels. We isolated the rates of Ca-c(2+) clearance by several mechanisms using combinations of the following agents (with their expected targets): Li+ or TEA substituted for Na+ (Na+-Ca2+ exchange), 1 mM La3+ applied after the depolarization (Na+-Ca2+ exchange and plasma membrane Ca2+-ATPase), 1 mu M thapsigargin (pumping into reticular stores), and 2 mu M carbonyl cyanide m-chlorophenylhydrazone (uptake into mitochondria). Remarkably, whenever [Ca2+](c) rose above similar to 500 nM, Ca-c(2+) clearance by mitochondria exceeded clearance by either Na+-Ca2+ exchange or the Ca2+ pumps of the plasma and reticular membranes. As [Ca2+](c) fell again, Ca2+ re-emerged from mitochondria, prolonging the final return to basal levels.