Studies of membrane-associated enzyme activities which are regulated by membrane potential

受膜电位调节的膜相关酶活性的研究

• 批准号: 05670082
• 负责人: YANAGISAWA Teruyuki
• 金额: $ 1.34万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05670082/
• 关键词: hyperpolarization; potassium channel opener; phospholipase C; phorbor ester; protein kinase C; Ca sensitivity; coronary artery; levcromakalim; 蛋白リン酸化酵素C; Ca感受性; 血管平滑筋; Kチャンネル開口薬; 収縮蛋白質

Studies in our laboratory have demonstrated that KCl-induced depolarization potentiates the increased Ca^<2+> sensitivity of contractile elements induced by endothelin-1 and that various K^+ channel openers (KCOs) which hyperpolarize membrane reduce the Ca^<2+> sensitivity and to inhibit agonist-induced contraction and synthesis of IP_3 in porcine or canine coronary artery. Thus, there are some possible transduction mechanisms by which the changes in level of membrane potential by altering KCl concentration in physiological salt solution (PSS) or by KCOs influence the Ca^<2+> sensitivity in high KCl-depolarized or phorbor ester-stimulated muscles.After the perfusion with 90 mM kc1-2.5 Mm CaCl_2 PSS (90K-2.5Ca), repolarization produced by 5 mM KCl-2.5 mM CaCl_2-PSS(5K-2.5Ca) or the removal of extracellualr Ca^<2+> ([Ca^<2+>]_0) and addition of 1 mM EGTA (90K-0Ca) induced decreases in [Ca^<2+>]_i and relaxation. The relaxation induced by 90K-0Ca was slower than induced by 5K-2.5Ca without significant difference in the decrease in [Ca^<2+>]i. The reduction of [Na^+]_0 did not slow down the relaxation in 0Ca. The [Ca^<2+>]i-force relation curve in 30K-0Ca was been that in 5K-0Ca and that in 90K-0Ca. The effect of levcromakalim was blocked by glibenclmide and counteracted by 20 mM -KC1 PSS.The [Ca^<2+>]i-force relationship curve obtained by changing [K^+]_0 stepwise in 2.5 mM CaCl_2-PSS was located to the right of that by changing [Ca^<2+>]_0 in 90 mM KCl-PSS.Thus, KCl-depolarization increases and hyperpolarization induced by KCOs decreases the Ca^<2+> sensitivity of contractile elements. There are signal transduction systems for sarcolemma to regulate the Ca^<2+> sensitivity of contractile elements including with enzyme activities by the level of membrane potential.

我们实验室的研究表明，KCl诱导的去极化增强了内皮素-1诱导的收缩元件Ca^2+敏感性的增加，并且使膜超极化的各种K^+通道开放剂（KCO）降低了Ca^2+敏感性并抑制猪或犬冠状动脉中激动剂诱导的收缩和IP_3的合成。因此，存在一些可能的转导机制，通过改变生理盐溶液(PSS)中的KCl浓度或通过KCO来改变膜电位水平，影响高KCl去极化或佛硼酯刺激的肌肉中的Ca ^ 2+ 敏感性。用90 mM kc1-2.5 Mm CaCl_2 PSS (90K-2.5Ca)灌注后，由 5 mM KCl-2.5 mM CaCl_2-PSS(5K-2.5Ca) 或去除细胞外 Ca^<2+> ([Ca^<2+>]_0) 并添加 1 mM EGTA (90K-0Ca) 诱导 [Ca^<2+>]_i 减少和松弛。由90K-0Ca诱导的松弛比由5K-2.5Ca诱导的慢，在[Ca 2+ ]i的减少方面没有显着差异。 [Na^+]_0 的减少并没有减缓 0Ca 的弛豫。 30K-0Ca中的[Ca^ 2+ ]i-力关系曲线是5K-0Ca和90K-0Ca中的。 levcromakalim 的作用被格列苯酰亚胺阻断，并被 20 mM -KC1 PSS 抵消。在 2.5 mM CaCl_2-PSS 中逐步改变 [K^+]_0 得到的 [Ca^<2+>]i-力关系曲线位于在 90 mM KCl-PSS 中改变 [Ca^<2+>]_0 得到的 [Ca^<2+>]i-力关系曲线的右侧。因此，KCl-去极化增加 KCO诱导的超极化降低了收缩元件的Ca^2+敏感性。存在用于肌膜的信号转导系统来调节收缩元件的Ca 2+ 敏感性，包括通过膜电位水平调节酶活性。

项目成果

T.Yanagisawa & Y.Okada: "The structure-actirity relation ship of KRN 23912 as anN-K by brid." Cardiovasc.Drug Rev.11. 94-115 (1993)

柳泽

M.Kageyama,T.Yanagisawa & N.Taira: "Calcitonin-gene relcted peptide relaxes porcine coronary arteries via cyclic AMP-dependent me chanisms.but not activction of ATP-sensitive potassium channels." J.Pharmacol.Exp.Ther.265. 565-574 (1993)

影山先生、柳泽先生

Toshio YAMAGISHI: "Relaxant mechanisms of cyclic AMP-increasing agents in canine coronary artery" Europ.J.PHarmacol.251. 253-262 (1994)

Toshio YAMAGISHI：“犬冠状动脉中环 AMP 增加剂的松弛机制”Europ.J.PHharmacol.251。

Yuji Okada et al.: "K^+ channel opening action and KRN2329-inducel recluction of Ca^<2+> persitivity of anterial mooth muscle." Arch.Intern.Pharmcodyn.Ther.(in press). (1994)

Yuji Okada 等人：“K^ 通道开放作用和 KRN2329 诱导前平滑肌 Ca^2 持续性的再收缩。”

T.Yamagishi,T.Yanagisawa,K.Satoh & N.Taira: "Relaxant me chanisms of cyclic AMP-in creasiy agents in porcine coronary srtery." Europ.J.Pharmacol.251. 253-262 (1994)

山岸T、柳泽T、佐藤K