Near membrane Ca2+ changes resulting from store release in neutrophils: Detection by FFP-18
Near membrane Ca2+ changes resulting from store release in neutrophils: Detection by FFP-18
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DOI：
10.1016/s0143-4160(96)90076-7
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发表时间：
1996-04-01
期刊：
影响因子：
4
通讯作者：
Hallett, MB
中科院分区：
文献类型：
--
作者：
Davies, EV;Hallett, MB
FFP-18通过与其乙酰氧基甲酯孵育而掺入人嗜中性粒细胞质膜的内表面。通过激发光谱的变化监测转化为Ca 2+敏感的细胞内指示剂。来自细胞外面向FFP-18的荧光被膜不渗透离子Ni 2+猝灭。在这些条件下的FFP-18的比率荧光测量允许检测由细胞内储存的Ca 2+释放引起的近膜Ca 2+变化。近膜和胞质Ca 2+的变化进行了测量的条件下，其中存储释放和Ca 2+内流所引发的FMLP，毒胡萝卜素或免疫复合物。有显着差异的时间和幅度附近的质膜和散装胞质Ca 2+浓度，这是一致的Ca 2+存储网站内的嗜中性粒细胞释放的毒胡萝卜素和FMLP，但Ca 2+释放网站与免疫复合物刺激接近膜的变化。因此，使用FFP-18监测质膜内表面附近的Ca 2+提供了中性粒细胞中存在两个不同Ca 2+储存位置的证据。
FFP-18 was incorporated into the inner face of the plasma membrane of human neutrophils by incubation with its acetoxymethyl ester. Conversion to the Ca2+ sensitive intracellular indicator was monitored by the change in excitation spectra. The fluorescence from extracellularly facing FFP-18 was quenched by the membrane impermeant ion Ni2+. Ratio fluorescence measurement of FFP-18 under these conditions permitted the detection of near membrane Ca2+ changes resulting from the release of Ca2+ from intracellular stores. Near membrane and cytosolic Ca2+ changes were measured under conditions in which store release and Ca2+ influx were triggered by FMLP, thapsigargin or immune complexes. There were significant differences in the timing and magnitude of Ca2+ changes near the plasma membrane and bulk cytosolic Ca2+ concentration, which were consistent with a Ca2+ storage site deep within the neutrophil released by thapsigargin and FMLP, but Ca2+ release sites with immune complex stimulation being close to the membrane. The use of FFP-18 to monitor Ca2+ near the inner face of the plasma membrane thus provides evidence for the existence of two distinct Ca2+ storage locations in neutrophils.