FEBS Letters | |
Na+/H+ exchange and Ca2+ influx | |
Akkerman, Jan Willem N.2  Siffert, Winfried1  | |
[1] Max-Planck-Institut für Biophysik, Kennedyallee 70, D-6000 Frankfurt am Main 70, FRG;Department of Haematology, University Hospital, 3511 GVUtrecht, The Netherlands | |
关键词: Platelet; Endothelial cell; Lymphocyte; Smooth muscle cell; Na+/H+ exchange; [Ca2+]i; cytosolic free Ca2+ concentration; Ca2+ 0; extracellular Ca2+; EIPA; ethylisopropylamiloride; [H+]i; cytosolic H+ concentration; [Na+]i; cytosolic Na+ concentration; Na+ 0 extracellular Na+; pHi; cytosolic pH; pH0; extracellular pH; Ins 1; 4; 5P3; inositol 1; 4; 5 trisphosphate; | |
DOI : 10.1016/0014-5793(89)81480-2 | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
Cell stimulation raises the cytosolic free Ca2+ concentration, [Ca2+]i, and induces activation of Na+/H+ exchange which raises the cytosolic pH, pHj. Recent studies have addressed the question whether Na+/H+ exchange plays a role in Ca2+ influx and, specifically, whether a rise in pHi alone suffices to open Ca2+ channels in the plasma membrane. Artificial cytosolic alkalinization can induce Ca2+ uptake across the plasma membrane of endothelial cells, lymphocytes and smooth muscle cells. Furthermore, inhibition of Na+/H+ exchange reduces aganist-induced Ca2+ influx in endothelial cells and platelets which supports the concept that pHi may regulate the opening of Ca2+ channels in the plasma membrane. Although these findings argue in favour of a role of Na+/H+ exchange in Ca2+ influx, the onset of pHi and Ca2+ rises, measured with fluorescent indicators, suggests that the increase in [Ca2+]i distinctly precedes the increase in pHi. This challenges the concept that alkalinization per se is a sufficient signal for the opening of Ca2+ channels in the plasma membrane.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
RO201912020292826ZK.pdf | 381KB | download |