Molecular-biological and pharmacological analysis of regulating sites of glycine receptor function in Xenopus oocytes using novel compounds

使用新型化合物对非洲爪蟾卵母细胞甘氨酸受体功能调节位点进行分子生物学和药理学分析

• 批准号: 11672266
• 负责人: TAKAHAMA Kazuo
• 金额: $ 2.18万
• 依托单位: Kumamoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11672266/
• 关键词: Glycine receptor; Dextromethorphan; Strychnine; Xenopus oocytes; α_1subunit; α_2subunit; Point mutant; Inwardly rectifing K^+ channel; Morphan compounds; α2サブユニット; 遅延整流性Kイオンチャネル

We have previously reported that dextromethorphan (DM), one of morphan derivatives, inhibited glycine-induced currents in single neuron acutely dissociated from rat brain. This study was designed to clarify the regulating site of glycine receptor function and to get further information about the action of DM and antitussives on other neuronal receptors and channels.【Results】1) DM, strychnine, codeine and caffeine inhibited the glycine-induced cur-rents in Xenopus oocytes expressing α_1-or α_2a-subunit of glycine receptor. IC_<50S> for DM and codeine were 5.2x10^<-5>M and 2.2x10^<-4>M, respectively, in the α_1, and 1.2x10^<-5>M and 5.5x10^<-5> M, respectively in the α_2. Both drugs showed more potent inhibitory action on the α_2 than α_1, while the reverse was true for strychnine and caffeine. 2) Out of newly synthesized 11 compounds, which have a morphan structure in the molecule, three compounds inhibited the currents induced by glycine in Xenopus oocytes expressing the α_1 subunit. 3) In the mutants, Y161F, F159Y/Y161F and S267I, of the α_1, the inhibitory action of DM was not changed, compared with the action in the wild type. On the other hand, the action of strychnine was potentiated in the double mutant, F159Y/Y161F than in the wild type. 4) In patch-clamp study using acutely dissociated dorsal raphe neurons of rats, DM inhibited not only the K^+ currents induced by 5-HT with 1.43x10^<-5> M of the IC_<50>, but also the currents irreversibly activated by intracellular GTPγS even in the absence of 5-HT.The results sugest that (1) the morphan structure might be a part of chemical structure essential for modifing the function of glycine receptors, (2) DM may have a site on the glycine receptor different from the site where Str acts.

我们以前已经报道说，右美甲泛（DM）是形态衍生物之一，抑制了甘氨酸诱导的单神经元中的甘氨酸诱导的电流，与大鼠脑急性分离。这项研究旨在阐明甘氨酸受体功能的调节部位，并获取有关DM和抗毒剂对其他神经元受体和通道的作用的进一步信息。 [结果] 1）DM，士宁宁，可待因和咖啡氨酸抑制了表达甘氨酸受体的α_1-ORα_2A亚基的异武卵母细胞中甘氨酸诱导的电流。 DM和可待因的IC_ <50S>分别在α_1中分别为5.2x10^<-5> m和2.2x10^<-4> m，在α_2中分别为1.2x10^<-5> m和5.5x10^<-5> m。两种药物在α_2上均表现出比α_1的潜在抑制作用更大，而对于士宁宁和咖啡氨酸而言，这种抑制作用是正确的。 2）在新合成的11种化合物中，该化合物在分子中具有形态结构，三种化合物抑制了表达α_1亚基的Xenopus卵母细胞中甘氨酸诱导的电流。 3）在突变体中，与野生型的作用相比，在α_1的Y161F，F159Y/Y161F和S267I中，DM的抑制作用没有改变。另一方面，比野生型中的双突变体，F159Y/Y161F的作用是在双突变体中的作用。 4）在使用大鼠的急性解离背部神经元的斑块钳研究中，DM不仅抑制了IC_ <50> 1.43x10^<-5> m的5-HT诱导的K^+电流，而且还抑制了在5-HERSISS中的结构，也可能会出现5-HER的结构（1）。为了修饰甘氨酸受体的功能，（2）DM在甘氨酸受体上可能具有与STR作用的位点不同的甘氨酸受体。

项目成果

Yoshinaka Murai,Kazuo Takahama,Norio Akaike.: "Preferential inhibition of L-and N-type calcium channels in the rat hippocampal neurons by cilnidipine."Brain Research. 854. 6-10 (2000)

Yoshinaka Murai、Kazuo Takahama、Norio Akaike.：“西尼地平优先抑制大鼠海马神经元中的 L 型和 N 型钙通道。”大脑研究。

Hitoshi Ishibashi,Takanobu Mochidome,Kazuo Takahama.: "Activation of potassium conductance by ophiopogonin-D in acutely dissociated rat paratracheal neurones."British.J.Pharmacol.. 132. 461-466 (2001)

Hitoshi Ishibashi、Takanobu Mochidome、Kazuo Takahama.：“麦冬皂苷-D 在急性分离的大鼠气管旁神经元中激活钾电导。”British.J.Pharmacol.. 132. 461-466 (2001)

Hitoshi Ishibashi, Takanobu Mochidome, Junpei Okai, Hiroyuki Ichiki, Hideaki Shimada, Kazuo Takahama.: "Activation of potassium conductance by ophio-pogonin-D in acutely dissociated rat paratracheal neurones."British.J.Pharmacol.. 132. 461-466 (2001)

Hitoshi Ishibashi、Takanobu Mochidome、Junpei Okai、Hiroyuki Ichiki、Hideaki Shimada、Kazuo Takahama.：“ophio-pogonin-D 在急性分离的大鼠气管旁神经元中激活钾电导。”British.J.Pharmacol.. 132. 461-466

Hitoshi Ishibashi,Kouichi Kuwano,Kazuo Takahama.: "Inhibition of the 5-HT1A receptor-mediated inwardly rectifying K^+ current by dextromethorphan in rat dorsal raphe neurons"Neuropharmacology. 39. 2302-2308 (2000)

Hitoshi Ishibashi，Kouichi Kuwano，Kazuo Takahama.：“右美沙芬对大鼠中缝背侧神经元中 5-HT1A 受体介导的内向整流 K 电流的抑制”神经药理学。

Takanobu Mochidome,Hitoshi Ishibashi,Kazuo Takahama.: "Bradykinin activates airway parasympathetic ganglion neurons by inhibiting M-currents."Neuroscience. (in press). (2001)

Takanobu Mochidome、Hitoshi Ishibashi、Kazuo Takahama.：“缓激肽通过抑制 M 电流激活气道副交感神经节神经元。”神经科学。