EFFECTS OF VOLATILE ANESTHETICS ON ENDOTHELIAL NITRIC OXIDE SYNTHESIS AND VASODILATION MEDIATED THOROUGH THE CaィイD12+ィエD1 INFLUX PROMOTED BY THE DEPLETION OF CaィイD12+ィエD1 IN ENDOPLASMIC RETICULUM

挥发性麻醉剂对内质网 CaiD12+D1 耗竭促进的 CaiD12+D1 内流介导的内皮一氧化氮合成和血管舒张的影响

• 批准号: 10671440
• 负责人: MIZUMOTO Kazuhiro
• 金额: $ 1.28万
• 依托单位: Wakayama Medical College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10671440/
• 关键词: Volatile Anesthetics; Nitric Oxide; Endoplasmic Reticulum; CaィイD12+ィエD1 influx; Vasodilation; Cyclic GMP; 内皮; チトクローム P450; Ca流入因子; cGMP; 血管内皮; Ca^<2+>(カルシウムイオン); チトクロームP450

Elevation of intracellular CaィイD12+ィエD1 level is and essential requisite for endothelial nitric oxide (NO) synthesis. As one of these pathways, it has been reported that the depletion of CaィイD12+ィエD1 in endoplasmic reticulum (ER) activated microsomal cytochrome P450 mono-oxygenase (P450 MO) and induces the biosynthesis of 5, 6-eopoxyeicosatrienoic acid (5, 6-EET), which in turn promote CaィイD12+ィエD1 influx from extracelluar fluids. Thapsigargin is one of the agents to induce this pathway. Volatile anesthetics have been demonstrated inhibit P450 MO activity in liver. However, little is known about their effects on vascular smooth muscle relaxation mediated though P450 MO in endothelium. The purpose of this study was to examine the effects of volatile anesthetics on endothelial P450 MO-mediated vasodilation.With institutional approval, rings with endothelium from isolated rat thoracic aorta were suspended under a resting tension of 3.0 g in Krebs' bicarbonate solution. The rings were prec … More ontracted with phenylephrine (3X10ィイD1-7ィエD1M ) and the relaxant effect of thapsigargin (10ィイD1-7ィエD1 to 10ィイD1-6ィエD1 M), which depletes CaィイD12+ィエD1 in ER, and that of 5, 6-EET (5X10ィイD1-6ィエD1 M) were tested in the presence or absence of volatile anesthetics (Halothane, Isoflurane, and Sevoflurane, 1 to 3 MAC in human). Thapsigargin-induced relaxation was also tested in the presence or absence of pretreatment with inhibitors, which were econazole (P450 MO inhibitor, 2X10ィイD1-5ィエD1 M) and NィイD1GィエD1-nitro-L-arginine (L-NA, 10ィイD1-5ィエD1 M).Thapsigargin caused a concentration-dependent relaxation, and that at 10ィイD1-6ィエD1 M was compatible with 5, 6-EET (5X10ィイD1-6ィエD1 M)-induced relaxation. Removal of endothelium or pretreatment with L-NA attenuated thapsigargin-induced relaxation significantly. The pretreatment with econazole also inhibited it significantly. Thapsigargin-induced relaxation was attenuated by Hal, Iso, and Sevo (1 to 3MAC) in a concentration-dependent manner. The potency of inhibitory effect of anesthetics on thapsigargin-induced relaxation was ranked as Hal > Iso > Sevo at 3 MAC. Relaxation induced by 5, 6-EET was not influenced by volatile anesthetics. The results of the current study confirm that thapsigargin-induced vasodilation is NO-dependent and regulated by endothelial P450 MO. It is indicated that volatile anesthetics attenuate endothelium-dependent vasodilation mediated via the CaィイD12+ィエD1 depletion in ER-induced CaィイD12+ィエD1 influx, and 3) this attenuation is mediated by the inhibition of P450 MO in endothelium by anesthetics. Less

细胞内CaィイD12+ィエD1水平的升高是内皮一氧化氮（NO）合成的必要条件。作为这些途径之一，据报道，内质网 (ER) 中 CaィイD12+ィエD1 的消耗激活微粒体细胞色素 P450 单加氧酶 (P450 MO)，并诱导 5, 6-环氧二十碳三烯酸 (5, 6-EET) 的生物合成，进而促进 CaィイD12+ィエD1从细胞外液流入。 Thapsigargin 是诱导该途径的药物之一。挥发性麻醉剂已被证明会抑制肝脏中 P450 MO 的活性。然而，人们对它们对内皮细胞中 P450 MO 介导的血管平滑肌松弛的影响知之甚少。本研究的目的是检查挥发性麻醉剂对内皮 P450 MO 介导的血管舒张的影响。经机构批准，将来自离体大鼠胸主动脉的内皮环悬浮在 Krebs 碳酸氢盐溶液中，静息张力为 3.0 g。这些环受去氧肾上腺素（3X10ィイD1-7ィエD1M）和毒胡萝卜素（10ィイD1-7ィエD1至10ィイD1-6ィエD1 M）的松弛作用的吸引，这会消耗CaィイD12+ィエD1 ER 和 5、6-EET (5X10ィイD1-6ィエD1 M) 进行了测试 是否存在挥发性麻醉剂（氟烷、异氟烷和七氟烷，人为 1 至 3 MAC）。还在存在或不存在抑制剂预处理的情况下测试了毒胡萝卜素诱导的松弛，抑制剂是益康唑（P450 MO抑制剂，2X10iiD1-5ィエD1 M）和NiiD1GiiD1-硝基-L-精氨酸（L-NA，10iiD1-5iiD1 M）。浓度依赖性松弛，并且在 10ィイD1-6ィエD1 M 与 5, 6-EET (5X10ィイD1-6ィエD1 M) 引起的松弛兼容。去除内皮或用 L-NA 预处理可显着减弱毒胡萝卜素诱导的松弛。益康唑预处理也能显着抑制其发生。 Hal、Iso 和 Sevo（1 至 3MAC）以浓度依赖性方式减弱毒胡萝卜素诱导的松弛。麻醉剂对毒胡萝卜素诱导的松弛的抑制效果在 3 MAC 时排序为 Hal > Iso > Sevo。 5, 6-EET 诱导的松弛不受挥发性麻醉剂的影响。目前的研究结果证实，毒胡萝卜素诱导的血管舒张是NO依赖性的，并受到内皮P450 MO的调节。结果表明，挥发性麻醉剂通过 ER 诱导的 CaiiD12+iiD1 流入中的 CaiiD12+iiD1 耗竭来减弱内皮依赖性血管舒张，并且 3）这种减弱是通过麻醉剂抑制内皮细胞中的 P450 MO 来介导的。较少的