Monitoring cytosolic free magnesium in cultured chicken heart cells by use of the fluorescent indicator Furaptra.
Monitoring cytosolic free magnesium in cultured chicken heart cells by use of the fluorescent indicator Furaptra.
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使用荧光指示剂 Furaptra 监测培养鸡心脏细胞中的胞质游离镁。
DOI：
10.1073/pnas.86.8.2981
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发表时间：
1989
影响因子：
11.1
通讯作者：
Lieberman,M
中科院分区：
文献类型：
--
作者：
Murphy,E;Freudenrich,CC;Levy,LA;London,RE;Lieberman,M
使用荧光指示剂2-[2-(5-羧基)恶唑]-5-羟基-6-氨基苯并呋喃-N,N,O-三乙酸(Furaptra)研究了培养的鸡胚心脏细胞中胞质游离镁浓度[Mg2+]i及其调节。添加皂苷后，Furaptra 从细胞中完全释放，证实了 Furaptra 的细胞内定位。基础 [Mg2+]i 平均为 0.48 +/- 0.03 mM (n = 31)，在灌注无钠溶液时增加了 3 倍。这种增加不能简单地归因于细胞内钠-细胞外镁交换，因为[Mg2+]i 的类似增加发生在无镁、无钠灌注中。此外，当从无钠灌注液中除去钙时，[Mg2+]i 的增加大大减弱。因此，无钠灌注时发生的 [Mg2+]i 增加的很大一部分取决于胞质游离钙的增加（细胞内钠-细胞外钙交换）。数据表明[Mg2+]i 被钙改变，很可能是由于细胞内结合位点的竞争。
Cytosolic free magnesium concentration [Mg2+]i and its regulation were studied in cultured embryonic chicken heart cells by use of the fluorescent indicator 2-[2-(5-carboxy)oxazole]-5-hydroxy-6-aminobenzofuran-N,N,O-triacet ic acid (Furaptra). The intracellular location of Furaptra was confirmed by its complete release from cells upon addition of saponin. The basal [Mg2+]i, which averaged 0.48 +/- 0.03 mM (n = 31), increased 3-fold on perfusion with sodium-free solution. This increase could not simply be attributed to intracellular sodium-extracellular magnesium exchange because a similar increase in [Mg2+]i occurred with magnesium-free, sodium-free perfusion. Furthermore, the increase in [Mg2+]i was largely attenuated when calcium was removed from the sodium-free perfusate. Thus, a substantial part of the increase in [Mg2+]i that occurs upon sodium-free perfusion is dependent on an increase in cytosolic free calcium (intracellular sodium-extracellular calcium exchange). The data suggest that [Mg2+]i is altered by calcium, most likely due to a competition for intracellular binding sites.