The effects of volatile anesthetics on recombinant adenosine triphosphate-sensitive potassium channels

挥发性麻醉药对重组三磷酸腺苷敏感钾通道的影响

基本信息

批准号：
17591636
负责人：
TANAKA Katsuya
金额：
$ 2.24万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17591636/
关键词：
Volatile anesthetics Isoflurane Vascular smooth muscle cells KATP channels pancreatic β cells patch clamp configurations 血菅内皮細胞

项目摘要

Background ; Recent evidence indicates that vascular adenosine triphosphate-sensitive potassium (K_<ATP>) channels in vascular smooth muscle cells are critical in the regulation of vascular tonus under both physiological and pathophysiological conditions. Studies of the interaction of volatile anesthetics with vascular K_<ATP> channels have been limited. In the present study, we investigated the molecular mechanism of isoflurane's action on vascular K_<ATP> channels.Methods ; Electrophysiologic experiments were performed using cell-attached and inside-out patch-clamp techniques to monitor native vascular K_<ATP> channels, and recombinant K_<ATP> channels comprised of inwardly rectifying potassium, channel subunits (Kir6. 1) and the sulfonylurea receptor (SUR2B). Isometric tension experiments were performed in rat thoracic aortic rings without endothelium.Results ; Application of isoflurane (0.5mM) to the bath solution during cell-attached recordings induced a significant increase in K_ … More <ATP> channel activity, which was greatly reduced by pretreatment with a selective inhibitor protein kinase A (PKA), Rp-cAMPS (100 μM). In inside-out patches, isoflurane failed to activate K_<ATP> channels. Isoflurane significantly activated wild type recombinant SUR2B/Kir6.1 in cell-attached patches. Isoflurane-induced activation of wild-type channels was diminished in the PKA-insensitive mutant SUR2B-T633A/Kir6.1, SUR2B-S1465A/Kir6. 1, and SUR2B/Kir6.1-S385A. In addition, we demonstrated that isoflurane-induced PKA activation was associated with isoflurane-induced decreases in isometric tension in the rat aorta.Conclusion ; Our results indicated that isoflurane activates K_<ATP> channels via PKA activation. PKA-dependent vasodilation induced by isoflurane also was observed in isometric tension experiments. Analysis of expressed vascular type K_<ATP>, channels suggested that PKA-mediated phosphorylation of both Kir6.1 and SUR2B subunits plays a pivotal role in isoflurane-induced vascular K_<ATP>, channel activation. Less

背景;最近的证据表明，血管平滑肌细胞中的三磷酸腺苷（K_ <ATP>）通道在生理和病理生理条件下对血管tonus的调节至关重要。挥发性麻醉与血管K_ <ATP>通道的相互作用的研究受到限制。在本研究中，我们研究了异氟烷对血管K_ <ATP> Channels.Methods的分子机制。使用细胞连接和内而外的斑块夹技术进行电生理实验，以监测天然血管K_ <ATP>通道，并重新组合K_ <ATP>通道，包括内部整流的钾，通道亚基（KIR6。）（KIR6。1）和sulfonylurourea受体（surfonylurea受体）。等距张力实验在没有内皮的大鼠胸主动脉环中进行。在细胞连接记录期间，在浴溶液中的异氟烷（0.5mm）的应用引起了K_…更多<ATP>通道活性的显着增加，通过使用选择性抑制剂蛋白激酶A（PKA），RP-camps（100μm），通过预处理大大降低了<ATP>通道活性。在内而外的补丁中，异氟烷未能激活K_ <ATP>通道。异氟烷在细胞附着的斑块中显着激活的野生型重组SUR2B/KIR6.1。异氟烷引起的野生型通道的激活减少了PKA不敏感的突变体SUR2B-T633A/KIR6.1，SUR2B-S1465A/KIR6。 1和sur2b/kir6.1-S385a。此外，我们证明了异氟烷诱导的PKA激活与大鼠主动脉的等距张力下降有关。我们的结果表明，异氟烷通过PKA激活激活K_ <ATP>通道。在等距张力实验中也观察到了异氟烷诱导的PKA依赖性血管舒张。对表达的血管型K_ <ATP>的分析，通道表明，PKA介导的KiR6.1和SUR2B亚基的磷酸化在异氟烷诱导的血管K_ <ATP>中起关键作用。较少的