Ca2+ flow via tunnels in polarized cells: Recharging of apical Ca2+ stores by focal Ca2+ entry through basal membrane patch
Ca2+ flow via tunnels in polarized cells: Recharging of apical Ca2+ stores by focal Ca2+ entry through basal membrane patch
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DOI：
10.1016/s0092-8674(00)81857-7
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发表时间：
1997-01-10
期刊：
影响因子：
64.5
通讯作者：
Petersen, OH
中科院分区：
文献类型：
--
作者：
Mogami, H;Nakano, K;Petersen, OH
细胞内钙离子储备库的耗尽诱导钙离子跨膜进入，从而允许储备库重新充电。在我们的实验中，在无钙溶液中，胰腺腺泡细胞中的钙存储被乙酰胆碱(ACh)刺激而耗尽。此后，钙离子只能通过附着在基底膜上的含CaCl2的移液管进入。通过膜片移液管对细胞内的钙离子进行再灌流时，细胞内的钙离子浓度不会升高，并且依赖于thapsigargin敏感的钙泵的运行。在局部钙离子进入一段时间后，ACh可再次引起细胞内钙离子浓度的升高，这种升高总是始于顶端分泌极。因此，顶端钙库的补给依赖于钙离子从基底部到分泌极的通道流动，而内质网钙泵在这一过程中是必不可少的。
Intracellular Ca2+ store depletion induces Ca2+ entry across the plasma membrane, allowing the store to recharge. In our experiments, Ca2+ stores in pancreatic acinar cells were depleted by acetylcholine (ACh) stimulation in Ca2+-free solution. Thereafter, Ca2+ entry was only allowed through a CaCl2-containing pipette attached to the basal membrane. Recharging intracellular Ca2+ stores via a patch pipette occurred without a rise in the cytosolic Ca2+ concentration and depended on the operation of a thapsigargin-sensitive Ca2+ pump. After a period of focal Ca2+ entry, ACh could again evoke a rise in the cytosolic Ca2+ concentration, and this rise always started in the apical secretory pole. Recharging the apical Ca2+ store therefore depends on Ca2+ flow through a tunnel from the basal to the secretory pole, and the endoplasmic reticulum Ca2+ pump is essential for this process.