Swelling activates chloride current and increases internal calcium in nonpigmented epithelial cells from the rabbit ciliary body.
Swelling activates chloride current and increases internal calcium in nonpigmented epithelial cells from the rabbit ciliary body.
复制标题
肿胀激活氯电流并增加兔睫状体非色素上皮细胞的内部钙。
DOI：
10.1002/jcp.1041640209
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Matthews,G
中科院分区：
文献类型：
--
作者：
Botchkin,LM;Matthews,G
在不等渗条件诱导的细胞肿胀过程中，采用膜片钳和 fura-2 联合测量来监测兔非色素睫状体上皮细胞 (NPE 细胞) 的膜电流和 [Ca]i。在存在 K 通道阻滞剂的情况下，细胞肿胀导致膜电流增加，同时 [Ca]i 增加。与膜变形相关的细胞结构变化可能是肿胀期间 [Ca]i 增加的原因。肿胀激活的电导对 CI 是可渗透的：它取决于跨细胞膜的 CI 浓度梯度，并且被 CI 通道阻滞剂 DIDS、SITS、NPPB 和 DIOA 阻断。尽管肿胀增加了 CI 电流和 [Ca]i，但没有证据表明 Ca 参与 CI 电导的调节。即使当 [Ca]i 用内部 Ca-BAPTA/Cs-BAPTA 混合物以高水平 (500 nM) 或低水平 (∼0) 强烈缓冲时，细胞肿胀也会激活电流。此外，当使用 Ca 离子载体增加 [Ca]i 时，CI 电导不受影响。也没有证据表明 cAMP 参与 CI 电导的调节：在 cAMP 抑制剂 (Rp-cAMP-S) 和 cAMP 模拟物 (Sp-cAMP-S) 存在的情况下，电流发生肿胀激活。数据表明 CI 电导和内部 Ca 独立参与 NPE 细胞中细胞体积的调节。 © 1995 Wiley-Liss, Inc.
Membrane current and [Ca]iin rabbit nonpigmented ciliary body epithelial cells (NPE cells) were monitored with combined patch‐clamp and fura‐2 measurements during cell swelling induced by anisosmotic conditions. In the presence of K‐channel blockers, cell swelling produced an increase in membrane current, accompanied by an increase in [Ca]i.Structural changes in the cell, associated with membrane deformation, may be the cause of the increase in [Ca]iduring swelling. The conductance activated by swelling was permeable to CI: it was dependent on the CI concentration gradient across the cell membrane, and it was blocked by the CI‐channel blockers DIDS, SITS, NPPB, and DIOA. Although swelling increased both CI current and [Ca]i, there was no evidence that Ca was involved in the regulation of the CI conductance. Cell swelling activated the current even when [Ca]iwas strongly buffered at an elevated level (500 nM) or at a low level (∼0) with internal Ca‐BAPTA/Cs‐BAPTA mixtures. In addition, CI conductance was unaffected when [Ca]iwas increased with a Ca ionophore. There was also no evidence that cAMP participates in the regulation of the CI conductance: swelling activation of the current occurred in the presence of cAMP inhibitor (Rp‐cAMP‐S) and cAMP mimic (Sp‐cAMP‐S). The data suggest independent involvement of CI conductance and internal Ca in the regulation of cell volume in NPE cells. © 1995 Wiley‐Liss, Inc.