Jensen P E, Mulvany M J, Aalkjaer C, Nilsson H, Yamaguchi H
Department of Pharmacology, University of Aarhus, Denmark.
Am J Physiol. 1993 Aug;265(2 Pt 2):H741-6. doi: 10.1152/ajpheart.1993.265.2.H741.
Free cytosolic Ca2+ was measured with sub-micrometer-tip, double-barrelled, Ca(2+)-selective electrodes and fura 2 in rat mesenteric resistance arteries. The purpose was to establish intracellular free Ca2+ concentration ([Ca2+]i) values in resting and stimulated vessels. Isolated vessels were mounted for isometric force measurements. Measured with electrodes, mean [Ca2+]i was 115 and 708 nM under resting and norepinephrine-activated conditions, respectively. Fura 2 was calibrated intracellularly including determination of the intracellular dissociation constant (Kd) of the fura 2:Ca2+ complex. The intracellular Kd was 342 nM. With this value of Kd, fura 2 measurements of mean [Ca2+]i were 129 and 537 nM under resting and norepinephrine-activated conditions, respectively. The values measured with the two techniques were thus in good accordance.
使用亚微米尖端的双管钙离子选择性电极和fura 2测量大鼠肠系膜阻力动脉中的游离胞质钙离子。目的是确定静息和受刺激血管中的细胞内游离钙离子浓度（[Ca2+]i）值。将分离的血管安装用于等长力测量。用电极测量，静息和去甲肾上腺素激活条件下的平均[Ca2+]i分别为115和708 nM。对fura 2进行细胞内校准，包括测定fura 2:Ca2+复合物的细胞内解离常数（Kd）。细胞内Kd为342 nM。使用该Kd值，fura 2测量的静息和去甲肾上腺素激活条件下的平均[Ca2+]i分别为129和537 nM。因此，两种技术测量的值吻合良好。
