Ca-dependent Cl channel in tracheal smooth muscle and airway hypersensitivity

气管平滑肌和气道过敏中的 Ca 依赖性 Cl 通道

• 批准号: 08672526
• 负责人: IMAIZUMI Yuji
• 金额: $ 1.41万
• 依托单位: Nagoya City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08672526/
• 关键词: trachea; Ca^<2+> dependent Cl^- current; Ca^<2+> dependent K^+ current; time-dependence; Ca^<2+> mobilization; whole-cell clamp; calmodulin-dependent; on-cell patch configuration; protein Kinase II; 気道平滑筋; クロライドチャネル; パッチクランプ; 気道過敏症; Ca^<2+>動態

The time and Ca^<2+> dependence of Ca^<2+> dependent Cl^- currents, which were activated by depolarization or caffeine, was examined in comparison with that of Ca^<2+> dependent K^+ current in single smooth muscle cells isolated from guinea-pig trachea. The activation of the K^+ current was faster than that of the Cl^- current, simply dependent on subplasmalemma Ca^<2+> concentration if the membrane potential was clamped at a steady level, and not dependent on time. On the other hand, the Cl^- current activation showed time-dependence. In the later part of the project, the simultaneous measurement of images of Ca^<2+> mobilization and membrane currents were performed. Ca^<2+> images were obtained from single cells which wereloaded with indo-1 or fluo-3 by simple diffusion from patch pipettes using a laser confocal fluorescent microscope (Nikon RCM8000). It was found that the activation of Ca^<2+> dependent Cl^- current was slower than the elevation of global Ca^<2+> concentration by ab … More out 100 msec. It has been reported recently by other research group that phosphorylation of the Cl^- channel protein by calmodulin-dependent protein kinase II is included in the inactivation of the Ca^<2+> dependent Cl^- channel in tracheal smooth muscle. Based on the slow time course of activation, it is rather difficult to explain the activation by the direct binding of Ca^<2+> to the channel. Pharmacological results, however suggest that the major contribution of channel phosphorylation by one of the protein kinases to the activation is unlikely. Moreover, the recording of single channel current responsible for the Ca^<2+> dependent Cl^- was tried under on-cell patch configuration in skinned single cells, where plasma membrane was permeabilized but intracellular signal transduction systems were kept available. In inside-out patch configuration, the channel current can not be recorded well. Under the on-cell patches, a large conductance Ca^<2+> dependent Cl^- channel currents were recorded. Since characteristics of the single channel current was somewhat different from those expected based on the macroscopic Cl^- currents, the existence of another type of Cl^- channel which may have smaller conductance can be assumed. Less

通过去极化或咖啡因激活的Ca^2+依赖性Cl^-电流的时间和Ca^2+依赖性，与从豚鼠气管分离的单个平滑肌细胞中的Ca^2+依赖性K^+电流进行比较。 K^+电流的激活比Cl^-电流的激活更快，如果膜电位被钳位在稳定水平，则仅取决于质膜下Ca^2+浓度，而不取决于时间。另一方面，Cl^-电流激活表现出时间依赖性。在该项目的后期部分，同时测量了Ca^2+动员和膜电流的图像。 Ca 2+ 图像是使用激光共焦荧光显微镜(Nikon RCM8000)通过从贴片移液管简单扩散而从负载有indo-1或fluo-3的单细胞获得的。研究发现，Ca^<2+> 依赖性 Cl^- 电流的激活比全局 Ca^<2+> 浓度的升高慢 ab … More 超过 100 毫秒。最近其他研究小组报道，钙调素依赖性蛋白激酶II对Cl^2-通道蛋白的磷酸化参与了气管平滑肌中Ca^2+依赖性Cl^2-通道的失活。基于激活的缓慢时间过程，通过Ca^2+与通道的直接结合来解释激活是相当困难的。然而，药理学结果表明，其中一种蛋白激酶的通道磷酸化对激活的主要贡献不太可能。此外，在带皮单细胞的细胞贴片配置下尝试记录负责Ca 2+ 依赖性Cl 2- 的单通道电流，其中质膜被透化但细胞内信号转导系统保持可用。在inside-out贴片配置中，通道电流不能被很好地记录。在细胞上贴片下，记录了大电导Ca 2+ 依赖性Cl 2- 通道电流。由于单通道电流的特性与基于宏观 Cl^- 电流的预期有些不同，因此可以假设存在另一种可能具有较小电导的 Cl^- 通道。较少的

项目成果

Katsuhiko Muraki et al: "Conpatative study of effects of iso proterenol and vaseactive intestinal polypeptide on voltage-dependent Ca^<2+> and Ca^<2+>-octivated K^+ currents in porcine tracheal smootl muscle cells" General Pharmacology. 30. 115-119 (1998)

Katsuhiko Muraki 等人：“异丙肾上腺素和血管活性肠多肽对猪气管平滑肌细胞中电压依赖性 Ca ^ 2 和 Ca ^ 2 激活的 K ^ 电流影响的协同研究”普通药理学。

Y.Imaizumi, et al.: "Smooth muscle exitation" T.B.Bolton,T.Tonaita, 527 (1996)

Y.Imaizumi 等人：“平滑肌退出”T.B.Bolton，T.Tonaita，527 (1996)

Satoshi Henmi et al.: "Time course of Ca^<2+>-deperdent K^+ and Cl^- curents in single smooth muscle cells of guinea-pig trachea." European Journal of Pharmacology. 306. 227-236 (1996)

Satoshi Henmi 等人：“豚鼠气管单个平滑肌细胞中 Ca^2-依赖性 K^ 和 Cl^- 电流的时间过程。”

今泉 祐治: "心血管以外の臓器に対するKチャネル開口薬の作用" 治療学. 30. 89-94 (1996)

Yuji Imaizumi：“K 通道开放剂对心血管系统以外的器官的影响”《治疗学》30. 89-94 (1996)。

Sotoshi Henmi, et al.: "Time course of Ca^<2+>-dependent K^+ and Cl^- currents in single smooth muscle cells of guinea-pig trochea" European Journal of Pharmacology. 306. 227-236 (1996)

Sotoshi Henmi等人：“豚鼠喉管单个平滑肌细胞中Ca^2依赖性K^和Cl^-电流的时间过程”《欧洲药理学杂志》。