Hosoki E, Iijima T
Department of Pharmacology, Akita University School of Medicine, Japan.
Eur J Pharmacol. 1994 Feb 15;266(3):213-8. doi: 10.1016/0922-4106(94)90129-5.
The regulation of intracellular free Ca2+ concentration ([Ca2+]i) was studied in cultured human aortic endothelial cells loaded with the fluorescent Ca2+ indicator fura-2. Histamine and ATP at concentrations of 10 microM and higher produced a biphasic change in [Ca2+]i, which consisted of an initial transient elevation followed by a sustained elevation. Reduction of the extracellular Cl- concentration to 40 mM, or exposure to the Cl- channel antagonist N-phenylanthranilic acid selectively prevented the sustained response to histamine or ATP, but they did not affect the sustained response to the Ca2+ ionophore ionomycin. Elevation of extracellular K+ concentration to 90 mM had no influence on the sustained response to histamine or ATP. These results suggest that the sustained elevation of [Ca2+]i in response to histamine and ATP is due to the Cl(-)-sensitive entry of extracellular Ca2+ in cultured human aortic endothelial cells.
在加载了荧光钙指示剂fura-2的培养人主动脉内皮细胞中，研究了细胞内游离钙离子浓度（[Ca2+]i）的调节情况。浓度为10 microM及以上的组胺和ATP会使[Ca2+]i产生双相变化，该变化包括最初的短暂升高，随后是持续升高。将细胞外Cl-浓度降低至40 mM，或暴露于Cl-通道拮抗剂N-苯基邻氨基苯甲酸，可选择性地阻止对组胺或ATP的持续反应，但它们不影响对Ca2+离子载体离子霉素的持续反应。将细胞外K+浓度升高至90 mM对组胺或ATP的持续反应没有影响。这些结果表明，在培养的人主动脉内皮细胞中，对组胺和ATP的反应导致的[Ca2+]i持续升高是由于细胞外Ca2+的Cl(-)敏感内流。
