...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Stretch-activated single K~+ channels account for whole-cell currents elicited by swelling
【24h】

Stretch-activated single K~+ channels account for whole-cell currents elicited by swelling

机译：拉伸激活的单个K〜+通道可解释肿胀引起的全细胞电流

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Functionally significant stretch-activated ion channels have been clearly identified in excitable cells. Although single-channel studies suggest their expression in other cell types, their activity in the whole-cell configuration has not been shown. This discrepancy makes their physiolog- ical significance doubtful and suggests that their mechanical activation is artifactual. Possible roles for these molecules in nonexcitable cells are acute cell-volume regulation and, in epithelial cells, the complex adjustment of ion fluxes across individual cell membranes when the rate of transepithelial transport changes. We report the results of experiments on isolated epithelial cells expressing in the basolateral mem- brane stretch-activated K~+ channels demonstrable by the cell-attached patch-clamp technique. In these cells, reversible whole-cell currents were elicited by both isosmotic and hy- posmotic cell swelling. Cation selectivity and block by inor- ganic agents were the same for single-channel and whole-cell currents, indicating that the same entity underlies single- channel and whole-cell currents and that the single-channel events are not artifactual. In these cells, when the rate of apical-membrane NaCl eutry increases, the cell Na~+ content and volume also increase, stimulating the Na~+,K~+-ATPase at the basolateral membrane, i.e., both Na~+ extrusion and K~+ uptake increase. We speculate that, under these conditions, the parallel activation of basolateral K~+ channels (by the swelling) elevates conductive K~+ loss, tending to maintain the cell K~+ content constant ("pum
机译：在兴奋性细胞中已明确鉴定出功能上重要的拉伸激活离子通道。尽管单通道研究表明它们在其他细胞类型中表达，但尚未显示它们在全细胞结构中的活性。这种差异使它们的生理意义令人怀疑，并表明它们的机械活化是人为的。这些分子在不可激发细胞中的可能作用是急性细胞体积调节，而在上皮细胞中，当跨上皮运输的速率改变时，跨单个细胞膜的离子通量的复杂调节。我们报告了在基底外侧膜拉伸激活的K +通道中表达的分离的上皮细胞的实验结果，这些通道可通过细胞附着膜片钳技术证实。在这些细胞中，同渗和同渗细胞肿胀均引起可逆的全细胞电流。单通道和全细胞电流对阳离子的选择性和被无机物阻断的作用相同，这表明单通道和全细胞电流是同一实体的基础，并且单通道事件不是人为的。在这些细胞中，当根尖膜NaCl的eutry速率增加时，细胞Na〜+的含量和体积也增加，从而刺激了基底外侧膜的Na〜+，K〜+ -ATPase，即Na〜+挤压和K〜+吸收增加。我们推测，在这些条件下，基底外侧钾离子通道的平行激活（通过溶胀）会增加导电性钾离子的损失，从而倾向于保持细胞钾离子含量恒定（“ pum

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号