Molecular mechanisms of gaseous anesthetics on glutamate receptors : Identification of action site and examination of anesthetic behaviors in knock-out mice

气体麻醉剂对谷氨酸受体的分子机制：作用位点的鉴定和基因敲除小鼠麻醉行为的检查

• 批准号: 13557130
• 负责人: YAMAKURA Tomohiro
• 金额: $ 2.43万
• 依托单位: Niigata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13557130/
• 关键词: Gaseous anesthetics; Glutamate receptor; NMDA receptor; AMPA receptor; Kainate receptor; Acetylcholine receptor; Knock-out mice

The effects of gaseous anesthetics on ligand-gated ion channels were investigated. Nitrous oxide (0.58 atmosphere (atm)) and xenon (0.46 atm) exhibited quite similar effects on various receptors. Glycine and GABA_A receptors were potentiated by gaseous anesthetics much less than by isoflurane, while nitrous oxide inhibited GABA_C receptors. Glutamate receptors were inhibited by gaseous anesthetics more markedly than by isoflurane, but less than by ethanol. NMDA receptors were the most sensitive among glutamate receptors, and were inhibited by nitrous oxide by 31%. 5-HT_3 receptors were slightly inhibited by nitrous oxide. The nicotinic acetylcholine (nACh) receptors were inhibited by gaseous and volatile anesthetics, but ethanol potentiated them. The sensitivity was different between α4β2 and α4β2 n ACh receptors ; α4β2 receptors were inhibited by nitrous oxide was non-competitive, and was slightly different depending on membrane potentials for NMDA receptors, but not for nACh receptors. The results of chimeric and point mutant rat nAChRs suggest that a single amino acid residue (β2-V253 or β4-F255) near the middle of the second transmembrane segment determines gaseous anesthetic sensitivity. Mutations of this residue in β subunits and the homologous residue of α4 subunits (α4-V254) showed that this position also determines sensitivities of n AChRs to acetylcholine, isoflurane, pentobarbital, and hexanol. The site-directed mutagenesis of ε2 and ζ1 NMDA receptor subunits showed that the conserved asparagine residue in the second hydrophobic segment M2 of the ζ1 subunit determines gaseous anesthetic sensitivity of NMDA receptors.

研究了气体麻醉剂对配体门控离子通道的影响。氧化亚氮（0.58大气压（atm））和氙（0.46大气压（atm））对各种受体的影响非常相似。气态麻醉剂对甘氨酸和GABA_A受体的增强作用远小于异氟醚，而氧化亚氮对GABA_C受体的抑制作用较弱。气体麻醉剂对谷氨酸受体的抑制作用比异氟醚更明显，但比乙醇更弱。NMDA受体是谷氨酸受体中最敏感的，氧化亚氮对NMDA受体的抑制率为31%。氧化亚氮对5-HT_3受体有轻微抑制作用。烟碱乙酰胆碱（nACh）受体受到气体和挥发性麻醉剂的抑制，但乙醇增强了它们的作用。α4β2和α4β2 n乙酰胆碱受体的敏感性存在差异；氧化亚氮对α4β2受体的抑制是非竞争性的，且对NMDA受体的膜电位略有不同，而对nACh受体的膜电位则无差异。嵌合和点突变大鼠nAChRs的结果表明，靠近第二跨膜段中间的单个氨基酸残基（β2-V253或β4-F255）决定了气体麻醉敏感性。该残基在β亚基和α4亚基的同源残基（α4- v254）的突变表明，该位置也决定了n achr对乙酰胆碱、异氟醚、戊巴比妥和己醇的敏感性。对ε2和ζ1 NMDA受体亚基的定点诱变表明，ζ1亚基第二疏水段M2上保守的天冬酰胺残基决定了NMDA受体的气体麻醉敏感性。

项目成果

Zhang Y, et al.: "Luciferase as a model for the site of inhaled anesthetic action"Anesth Analg. 93(5). 1246-1252 (2001)

张 Y 等人：“荧光素酶作为吸入麻醉作用部位的模型”Anesth Analg。

Zhan RZ, et al.: "Ischemic preconditioning is capable of inducing mitochondrial tolerance in the rat brain"Anesthesiology. 97(4). 896-901 (2002)

Zhan RZ等人：“缺血预处理能够诱导大鼠大脑中的线粒体耐受性”麻醉学。

Kitano T, et al.: "Characterization of N-methyl-D-aspartate receptor subunits involved in acute ammonia toxicity"Neurochem Int. 44(2). 83-90 (2004)

Kitano T 等人：“参与急性氨毒性的 N-甲基-D-天冬氨酸受体亚基的表征”Neurochem Int。

Petrenko AB, et al.: "Recent Advances in Anaesthesia and Intensive Care"Greenwich Medical Media Limited. 177-207 (2003)

Petrenko AB 等人：“麻醉和重症监护的最新进展”格林威治医疗媒体有限公司。

Yamakura T, et al.: "Anesthetics and ion channels : molecular models and sites of action"Annu. Rev. Phamacol. Toxicol.. 41. 23-51 (2001)

Yamakura T 等人：“麻醉剂和离子通道：分子模型和作用位点”Annu。