2-Aminoethoxydiphenyl borate affects the inositol 1,4,5-trisphosphate receptor, the intracellular Ca2+ pump and the non-specific Ca2+ leak from the non-mitochondrial Ca2+ stores in permeabilized A7r5 cells
2-Aminoethoxydiphenyl borate affects the inositol 1,4,5-trisphosphate receptor, the intracellular Ca2+ pump and the non-specific Ca2+ leak from the non-mitochondrial Ca2+ stores in permeabilized A7r5 cells
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DOI：
10.1054/ceca.2000.0163
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发表时间：
2001-02-01
期刊：
影响因子：
4
通讯作者：
Parys, JB
中科院分区：
文献类型：
--
作者：
Missiaen, L;Callewaert, G;Parys, JB
2-氨基乙氧基二苯硼酸酯(2APB)是一种膜通透性阻断剂，可阻断1，4，5-三磷酸(IP3)诱导的钙双向流动条件下的钙释放。我们现在研究了2APB对通透性A7r5平滑肌细胞非线粒体钙库摄取Ca-45(2+)的影响，以及对基础和IP3刺激的单向Ca-45(2+)外流的影响。2APB抑制IP3诱导的钙释放，在36µm时抑制作用达到一半，而不影响[H-3]IP与受体的结合。这种抑制作用不依赖于IP3、ATP或游离钙离子浓度。非线粒体钙库的钙泵在91um 2APB时被半最大抑制。较高浓度的2APB增加了钙离子的非特异性渗漏。我们认为2APB不能作为IP3诱导的钙释放的选择性阻断剂。我们的结果可以解释在完整细胞中观察到的2APB的各种作用。(C)2001哈考出版有限公司。
2-Aminoethoxydiphenyl borate (2APB) is a membrane-permeable blocker of the inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release in bi-directional Ca2+-flux conditions. We have now studied the effects of 2APB on the Ca-45(2+) uptake into, and on the basal and IP3-stimulated unidirectional Ca-45(2+) efflux from the non-mitochondrial Ca2+ stores in permeabilized A7r5 smooth-muscle cells. 2APB inhibited the IP3-induced Ca2+ release, with a half maximal inhibition at 36 muM 2APB, without affecting [H-3]IP, binding to the receptor. This inhibition did not depend on the IP3, ATP or free Ca2+ concentration. The Ca2+ pumps of the non-mitochondrial Ca2+ stores were half-maximally inhibited at 91 muM 2APB. Higher concentrations of 2APB increased the non-specific leak of Ca2+ from the stores. We conclude that 2APB can not be considered as a selective blocker of the IP3-induced Ca2+ release. Our results can explain the various effects of 2APB observed in intact cells. (C) 2001 Harcourt Publishers Ltd.