Monitoring cytosolic free magnesium in cultured chicken heart cells by use of the fluorescent indicator Furaptra

摘要: Abstract 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 Furaptra was confirmed complete release from upon addition saponin. 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 sodium-extracellular exchange because a similar occurred magnesium-free, perfusion. Furthermore, largely attenuated when calcium removed perfusate. Thus, substantial part that occurs is dependent an cytosolic (intracellular exchange). data suggest altered calcium, most likely due competition for binding sites.