Measurement of cytoplasmic free Ca2+ concentration in bovine tracheal smooth muscle using aequorin.
Measurement of cytoplasmic free Ca2+ concentration in bovine tracheal smooth muscle using aequorin.
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使用水母发光蛋白测量牛气管平滑肌中细胞质游离 Ca2 浓度。
DOI：
10.1152/ajpcell.1987.253.6.c817
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Rasmussen,H
中科院分区：
文献类型：
--
作者：
Takuwa,Y;Takuwa,N;Rasmussen,H
使用水母发光蛋白测量牛气管平滑肌条中的细胞质游离Ca2+浓度。卡巴胆碱诱导水母发光蛋白发光快速上升，在 1-2 分钟内达到峰值，然后在 5-6 分钟内降至稳定水平。该平台逐渐下降，但 2 小时后仍显着高于基线值。最初的 Ca2+ 瞬变是由于细胞内咖啡因敏感池中的 Ca2+ 动员所致。该平台期似乎是由于 Ca2+ 流入造成的。组胺或 5-羟色胺（血清素）也会诱导 Ca2+ 瞬变，然后是平台期，该平台期低于卡巴胆碱诱导的水平。与卡巴胆碱诱导的收缩中观察到的持续平台期相比，这两种激动剂中的任何一种产生的等长张力显示出逐渐下降。细胞外高 K+ 诱导水母发光蛋白发光呈剂量依赖性增加，这完全是由于 Ca2+ 跨质膜流入，并受到 Ca2+ 通道拮抗剂尼莫地平的极大抑制。这些结果表明，卡巴胆碱诱导的气管平滑肌收缩涉及两种时间和空间上不同的 Ca2+ 依赖性机制。
The cytoplasmic free Ca2+ concentration in bovine tracheal smooth muscle strips was measured using aequorin. Carbachol induces a rapid rise in aequorin luminescence, which reaches a peak within 1-2 min and then falls to a plateau level in 5-6 min. This plateau gradually declines but remains significantly above the base-line value after 2 h. The initial Ca2+ transient is due to Ca2+ mobilization from an intracellular caffeine-sensitive pool. The plateau appears to be due to Ca2+ influx. Histamine or 5-hydroxytryptamine (serotonin) also induce a Ca2+ transient followed by a plateau phase which is lower than that induced by carbachol. The isometric tension generated by either of these two agonists shows a gradual decline in contrast to the sustained plateau seen in the carbachol-induced contraction. Extracellular high K+ induces a dose-dependent increase in aequorin luminescence that is totally due to Ca2+ influx across the plasma membrane and is greatly inhibited by a Ca2+-channel antagonist, nimodipine. These results suggest that two temporally and spatially different Ca2+-dependent mechanisms are involved in carbachol-induced tracheal smooth muscle contraction.