Activation of different Cl currents in Xenopus oocytes by Ca liberated from stores and by capacitative Ca influx.
Activation of different Cl currents in Xenopus oocytes by Ca liberated from stores and by capacitative Ca influx.
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DOI：
10.1085/jgp.108.3.157
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发表时间：
1996-09
影响因子：
3.8
通讯作者：
Hartzell, HC
中科院分区：
文献类型：
--
作者：
Hartzell, HC
非洲爪哇卵母细胞是研究钙信号转导的良好模型系统。本研究的目的是详细研究注射1，4，5-三磷酸肌醇(IP3)对非洲爪哇卵母细胞电压钳制的钙激活氯电流的影响。将IP3注入非洲爪哇卵母细胞，可激活两种不同的钙激活氯离子电流。ICl-1被迅速激活(注射IP3后5min内)，除极后呈现时间依赖的激活，瞬时激活与ECL附近的翻转电位呈线性瞬时IV关系，激活曲线的半最大激活电压约为200 mV。ICL-2D在注射IP3后缓慢刺激(半最大刺激发生在注射后约3分钟)。ICL-2D具有强烈的外向整流瞬时IV关系，在ECL附近具有翻转电位，并被超极化激活，其半最大激活电压为-105 mV。ICL-2D不能被商店释放的钙激活，但可以被钙内流激活。相反，ICL-1可被细胞内钙库释放的钙刺激。如果钙驱动力在ICL-1通道的去极化之前立即被超极化增加，那么它也可以被通过商店操作的通道的钙内流所刺激。钙离子内流和钙释放激活的两种电流的描述为非洲爪哇卵母细胞钙的调节提供了新的见解和问题。
Xenopus oocytes are an excellent model system for studying Ca signaling. The purpose of this study was to characterize in detail the Ca-activated Cl currents evoked by injection of inositol 1,4,5- trisphosphate (IP3) into Xenopus oocytes voltage-clamped with two microelectrodes. Injection of IP3 into Xenopus oocytes activates two different Ca-activated Cl currents. ICl-1 is stimulated rapidly (within 5 s after IP3 injection), exhibits time-dependent activation upon depolarization, a linear instantaneous IV relationship with a reversal potential near ECl, and a curvilinear activation curve with an approximate half-maximal activation voltage of > 200 mV. ICl-2D is stimulated slowly after IP3 injection (half-maximal stimulation occurs approximately 3 min after injection). ICl-2D has a strongly outwardly rectifying instantaneous IV relationship with a reversal potential near ECl and is activated by hyperpolarization with a half-maximal activation voltage of -105 mV. ICl-2D cannot be activated by Ca released from stores but is activated by Ca influx. In contrast, ICl-1 can be stimulated by Ca released from intracellular Ca stores. It can also be stimulated by Ca influx through store-operated channels if the Ca driving force is increased by a hyperpolarization immediately before the depolarization that gates ICl-1 channels. The description of two currents activated by influx and Ca release from stores provides new insights into and questions about the regulation of Ca in Xenopus oocytes.
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影响因子：
4.5
作者：
BOTON, R;SINGER, D;DASCAL, N
通讯作者：
DASCAL, N
DOI：
10.1098/rspb.1987.0033
发表时间：
1987-06-22
期刊：
PROCEEDINGS OF THE ROYAL SOCIETY SERIES B-BIOLOGICAL SCIENCES
影响因子：
--
作者：
PARKER, I;MILEDI, R
通讯作者：
MILEDI, R
影响因子：
4
作者：
LUPUMEIRI, M;BEITOR, A;ORON, Y
通讯作者：
ORON, Y
影响因子：
5.5
作者：
HOTH, M;PENNER, R
通讯作者：
PENNER, R
DOI：
10.1098/rspb.1982.0056
发表时间：
1982-01-01
期刊：
PROCEEDINGS OF THE ROYAL SOCIETY SERIES B-BIOLOGICAL SCIENCES
影响因子：
--
作者：
MILEDI, R
通讯作者：
MILEDI, R