Rotrosen D, Gallin J I
J Cell Biol. 1986 Dec;103(6 Pt 1):2379-87. doi: 10.1083/jcb.103.6.2379.
Considerable evidence suggests that Ca2+ modulates endothelial cell metabolic and morphologic responses to mediators of inflammation. We have used the fluorescent Ca2+ indicator, quin2, to monitor endothelial cell cytosolic free Ca2+, [Ca2+]i, in cultured human umbilical vein endothelial cells. Histamine stimulated an increase in [Ca2+]i from a resting level of 111 +/- 4 nM (mean +/- SEM, n = 10) to micromolar levels; maximal and half-maximal responses were elicited by 10(-4) M and 5 X 10(-6) M histamine, respectively. The rise in [Ca2+]i occurred with no detectable latency, attained peak values 15-30 s after addition of stimulus, and decayed to a sustained elevation of [Ca2+]i two- to threefold resting. H1 receptor specificity was demonstrated for the histamine-stimulated changes in [Ca2+]i. Experiments in Ca2+-free medium and in the presence of pyrilamine or the Ca2+ entry blockers Co2+ or Mn2+, indicated that Ca2+ mobilization from intracellular pools accounts for the initial rise, whereas influx of extracellular Ca2+ and continued H1 receptor occupancy are required for sustained elevation of [Ca2+]i. Ionomycin-sensitive intracellular Ca2+ stores were completely depleted by 4 min of exposure to 5 X 10(-6) M histamine. Verapamil or depolarization of endothelial cells in 120 mM K+ did not alter resting or histamine-stimulated [Ca2+]i, suggesting that histamine-elicited changes are not mediated by Ca2+ influx through voltage-gated channels. Endothelial cells grown on polycarbonate filters restricted the diffusion of a trypan blue-albumin complex; histamine (through an H1-selective effect) promoted trypan blue-albumin diffusion with a concentration dependency similar to that for the histamine-elicited rise in [Ca2+]i. Exposure of endothelial cells to histamine (10(-5) M) or ionomycin (10(-7) M) was associated with a decline in endothelial F-actin (relative F-actin content, 0.76 +/- 0.07 vs. 1.00 +/- 0.05; histamine vs. control, P less than 0.05; relative F-actin content, 0.72 +/- 0.06 vs. 1.00 +/- 0.05; ionomycin vs. control, P less than 0.01). The data support a role for cytosolic calcium in the regulation of endothelial shape change and vessel wall permeability in response to histamine.
大量证据表明，Ca2+可调节内皮细胞对炎症介质的代谢和形态学反应。我们使用荧光Ca2+指示剂喹啉-2来监测培养的人脐静脉内皮细胞中的内皮细胞胞质游离Ca2+，即[Ca2+]i。组胺刺激[Ca2+]i从静息水平111±4 nM（平均值±标准误，n = 10）升高至微摩尔水平；最大反应和半最大反应分别由10(-4) M和5×10(-6) M组胺引起。[Ca2+]i的升高无明显延迟，在添加刺激后15 - 30秒达到峰值，并衰减至[Ca2+]i维持在静息水平的两到三倍。组胺刺激引起的[Ca2+]i变化具有H1受体特异性。在无Ca2+培养基中以及存在吡苄明或Ca2+内流阻滞剂Co2+或Mn2+的情况下进行的实验表明，细胞内钙库释放Ca2+导致最初的升高，而细胞外Ca2+的内流和H1受体的持续占据是[Ca2+]i持续升高所必需的。暴露于5×10(-6) M组胺4分钟可使离子霉素敏感的细胞内Ca2+储存完全耗尽。维拉帕米或在120 mM K+中使内皮细胞去极化并未改变静息或组胺刺激的[Ca2+]i，这表明组胺引起的变化不是由通过电压门控通道的Ca2+内流介导的。在聚碳酸酯滤膜上生长的内皮细胞限制了台盼蓝 - 白蛋白复合物的扩散；组胺（通过H1选择性作用）促进台盼蓝 - 白蛋白扩散，其浓度依赖性与组胺引起的[Ca2+]i升高相似。将内皮细胞暴露于组胺（10(-5) M）或离子霉素（10(-7) M）会导致内皮F - 肌动蛋白减少（相对F - 肌动蛋白含量，组胺组为0.76±0.07，对照组为1.00±0.05；P < 0.05；离子霉素组为0.72±0.06，对照组为1.00±0.05；P < 0.01）。这些数据支持胞质钙在调节内皮细胞形态变化和血管壁通透性以响应组胺方面发挥作用。
