Department of Internal Medicine, Division of Angiology, J. W. Goethe-University, Theodor-Stern-Kai 7, 6000, Frankfurt, Main, Germany.
Platelets. 1991;2(1):19-24. doi: 10.3109/09537109109005498.
Two fluorescent calcium indicators, Fura 2 and Indo 1 were compared with Quin 2 for the measurement of cytosolic free calcium concentrations (Ca(2+))(1) in intact platelets. The free calcium ions were quantitatively evaluated using a single excitation wavelength fluorimeter before and after stimulation with the Ca(2+) ionophores ionomycin and A23187, platelet activating factor (PAF) and arachidonic acid (AA). Using Quin 2 no rise in (Ca(2+))(i) could be registered by stimulation with the weak agonists PAF and AA in subthreshold concentrations for aggregation in contrast to Indo 1 and, to a lesser extent, Fura 2. Stimulation with ionomycin and A23187 led to a significant rise in (Ca(2+))(i) detected by all three indicators. The reproducibility was best for Indo 1. The three fluorescence indicators differed in their influence on platelet function and in their physical properties. Higher fluorescence intensities for Fura 2, and especially Indo 1, allowed a much lower indicator concentration of about 2-10% with a 10-fold improvement in the signal/noise ratio with Indo 1. While there was no difference in the volume distribution curves of the dye-loaded platelets, Quin 2-loaded platelets showed a significantly diminished response to collagen-and ADP-induced aggregation.
两种荧光钙指示剂 Fura 2 和 Indo 1 与 Quin 2 相比，用于测量完整血小板细胞浆游离钙浓度 (Ca(2+))(1)。使用单激发波长荧光计在刺激 Ca(2+)载体离子霉素和 A23187、血小板激活因子 (PAF) 和花生四烯酸 (AA)前后对游离钙离子进行定量评估。使用 Quin 2，在低于聚集的亚阈值浓度下用弱激动剂 PAF 和 AA 刺激时，与 Indo 1 相比，（Ca(2+))(i) 没有升高，与 Fura 2 相比，（Ca(2+))(i) 升高程度较小。离子霉素和 A23187 的刺激导致所有三种指示剂都检测到 (Ca(2+))(i) 的显著升高。 Indo 1 的重现性最好。这三种荧光指示剂在对血小板功能的影响和物理性质上存在差异。Fura 2 的荧光强度更高，尤其是 Indo 1，允许指示剂浓度低至约 2-10%，信号/噪声比提高 10 倍。虽然负载有染料的血小板的体积分布曲线没有差异，但 Quin 2 负载的血小板对胶原和 ADP 诱导的聚集的反应明显减弱。
