Nifedipine is calcium channels and pumps blocker widely used in medicine. However, mechanisms of nifedipine action in blood are not clear. In particular, the influence of nifedipine on erythrocytes is far from completely understood. In this work, applying scanning flow cytometry, we observed experimentally for the first time the dynamics behind a significant increase of HCO3 - /Cl- transmembrane exchange rate of CDB3 (main anion exchanger, AE1, Band 3, SLC4A1) of human erythrocytes in the presence of nifedipine in blood. It was found that the rate of CDB3 activation is not limited by the rate of nifedipine binding and/or Ca2+ transport. In order to explain the experimental data, we suggested a kinetic model assuming that the rate of CDB3 activation is limited by the dynamics of the balance between two intracellular processes (1) the activation of CDB3 limited by its interaction with intracellular Ca2+ , and (2) the spontaneous deactivation of CDB3. Thus the use of scanning flow cytometry allowed to clarify quantitatively the molecular kinetic mechanism of nifedipine action on human erythrocytes. In particular, the efficiency (~30) and rates of activation (~0.3 min-1 ) and deactivation (~10-3 min-1 ) of CDB3 in human erythrocytes was evaluated for two donors. © 2019 International Society for Advancement of Cytometry.

中文翻译：

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硝苯地平对人红细胞中CDB3活化的拟议动力学研究，采用扫描流式细胞术。

硝苯地平是广泛用于医学中的钙通道和泵阻滞剂。但是，硝苯地平在血液中的作用机理尚不清楚。特别是，硝苯地平对红细胞的影响远未完全弄清。在这项工作中，我们应用扫描流式细胞术，首次通过实验观察了人类红细胞中CDB3（主要阴离子交换剂AE1，Band 3，SLC4A1）的HCO3- / Cl-跨膜交换速率显着增加的动力学。血液中存在硝苯地平。发现CDB3活化速率不受硝苯地平结合和/或Ca 2+转运速率的限制。为了说明实验数据，我们提出了一个动力学模型，假设CDB3激活的速率受两个细胞内过程之间的平衡动力学的限制：（1）CDB3的激活受其与细胞内Ca2 +相互作用的限制；（2）CDB3的自发失活。因此，使用扫描流式细胞术可以定量地阐明硝苯地平对人红细胞作用的分子动力学机制。特别是，评估了两个供体的人红细胞中CDB3的效率（〜30）和活化速率（〜0.3 min-1）和失活速率（〜10-3 min-1）。©2019国际细胞计数学会。因此，使用扫描流式细胞术可以定量地阐明硝苯地平对人红细胞作用的分子动力学机理。特别是，评估了两个供体的人红细胞中CDB3的效率（〜30）和活化速率（〜0.3 min-1）和失活速率（〜10-3 min-1）。©2019国际细胞计数学会。因此，使用扫描流式细胞术可以定量地阐明硝苯地平对人红细胞作用的分子动力学机理。特别是，评估了两个供体的人红细胞中CDB3的效率（〜30）和活化速率（〜0.3 min-1）和失活速率（〜10-3 min-1）。©2019国际细胞计数学会。