Pharmacological study on the mechanism underlying the development of NO-tolerance

NO耐受性发生机制的药理学研究

• 批准号: 15390083
• 负责人: ITOH Takeo
• 金额: $ 7.3万
• 依托单位: NAGOYA CITY UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15390083/
• 关键词: nitrate tolerance; superoxide; nitric oxide; agiotensin II; glyceryl trinitrate; angiotensin receptors; endothelial cells; ascorbate; アンギオテンシンII; 1型アンギオテンシンII受容体; 血管平滑筋; 肺静脈; cyclic GMP; プロテインキナーゼC; 抵抗血管; 括性酸素

To attempt to clarify the possible role of superoxide on the mechanism underlying nitrate-tolerance, we examined this by a use of a nitrate-tolerance rabbit. This model was made by an application of transdermal glyceryl trinitrate (GTN) patches continuously for 10 days (GTN-treated rabbit). To examine the possible role of type 1 angiotensin II receptor (AT_1R) on this mechanism, AT_1R blocker valsartan (GTN+Valsartan-treated rabbit) or the antioxidant ascorbate (GTN+Ascorbate-treated rabbits) was co-administered with the NTG in some rabbits.1) In endothelium-denuded mesenteric resistant arteries, the relaxation ability of GTN, as well as the nitric oxide donor NOC-7, was significantly reduced in GTN-treated rabbits. In B-escin-skinned smooth muscles, the relaxing ability of 8-Br-cGMP was also downregulated in GTN-treated rabbits. Neither the conventional and/or novel PKCs inhibitor GF109203X (0.6 μM) nor a PKC activator phorbol 12,13-dibutyrate (PDBu, 0.1 μM) modified this downregulati … More on of cGMP-mediated relaxation seen in GTN-treated rabbits. These results suggest that the conventional and/or novel PKCs do not play a major role in the maintaining downregulation of cGMP-mediated relaxation in smooth muscle of mesenteric resistance arteries in GTN-treated rabbits.2) We examined to determine whether long-term in vivo administration of GTN downregulates the endothelium-dependent relaxation induced by acetylcholine (ACh) in rabbit intrapulmonary veins and, if so, whether the AT1R blocker valsartan normalizes this downregulation. In the rabbit intrapulmonary vein, ACh produces an endothelium-dependent relaxation mainly through an action mediated by endothelium-derived nitric oxide. The ACh-induced relaxation was downregulated and the production of superoxide by the endothelial cells was increased in GTN-treated rabbits, and these were normalized in GTN+Valsartan-treated rabbits. It is suggested that the increased superoxide in the endothelial cell through an action mediated by AT_1R contributes to the downregulation of the endothelium-dependent relaxation in rabbit pulmonary veins.3) We examined to determine whether long-term in vivo administration of GTN downregulates the hyperpolarization induced by ACh in rabbit aortic valve endothelial cells (AVECs) and, if so, whether antioxidant agents can normalize this downregulated hyperpolarization. In rabbit AVECs application of ACh produces a hyperpolarization due to co-activations of CTX-sensitive and apamin-sensitive K_<Ca> channels. The ACh-induced hyperpolarization is downregulated in GTN-treated rabbits and these are normalized when the antioxidant ascorbate was in vivo co-administered with the NTG (but not by its in vitro application). It is suggested that superoxide plays a pathophysiological role in the development and/or maintenance of the downregulation of ACh-induced hyperpolarization in AVECs in NTG-treated rabbits. Less

为了阐明超氧化物对硝酸盐耐受性机制的可能作用，我们通过使用硝酸盐耐受性家兔对此进行了研究。该模型通过连续10天应用经皮硝酸甘油酯（GTN）贴剂（GTN处理的家兔）制成。为了研究1型血管紧张素II受体（AT_1R）在这一机制中的可能作用，AT_1R阻断剂缬沙坦（valsartan）（GTN+缬沙坦处理的兔）或抗氧化剂抗坏血酸盐（GTN+抗坏血酸处理的兔）在一些兔中与NTG共同施用。1）在内皮剥脱的肠系膜阻力动脉中，GTN的舒张能力以及一氧化氮供体NOC-7，在GTN处理的兔中显著降低。在β-七叶皂苷皮肤的平滑肌中，8-Br-cGMP的舒张能力在GTN处理的兔中也下调。传统和/或新型PKC抑制剂GF 109203 X（0.6 μM）和PKC激活剂佛波醇12，13-二丁酸酯（PDBu，0.1 μM）都不能改变这种下调。 ...更多信息 在GTN处理的兔中观察到cGMP介导的舒张的增加。这些结果表明，传统的和/或新的PKC在维持GTN处理的兔肠系膜阻力动脉平滑肌cGMP介导的舒张的下调中不起主要作用。2）我们检查以确定长期体内施用GTN是否下调兔肺内静脉中乙酰胆碱（ACh）诱导的内皮依赖性舒张，如果是，AT 1 R阻断剂缬沙坦是否能使这种下调正常化。在兔肺内静脉，ACh主要通过内皮源性一氧化氮介导的作用产生内皮依赖性舒张。GTN处理组ACh诱导的舒张功能下调，内皮细胞产生超氧化物增加，而GTN+缬沙坦处理组则恢复正常。提示AT_1R介导的内皮细胞内超氧阴离子的增加参与了肺静脉内皮依赖性舒张功能的下调。3）我们研究了在体内长期给予GTN是否下调ACh诱导的兔主动脉瓣内皮细胞（AVECs）超极化，如果是，抗氧化剂是否可以使这种下调的超极化正常化。在兔AVEC中，ACh的应用由于共激活CTX敏感性和apamin敏感性K通道而产生超极化<Ca>。乙酰胆碱诱导的超极化下调GTN治疗的兔子，这些正常化时，抗氧化剂抗坏血酸在体内共同管理的NTG（但不是通过其在体外应用）。这表明超氧化物在NTG处理兔AVEC中ACh诱导的超极化下调的发展和/或维持中发挥病理生理作用。少

项目成果

Reduced hyperpolarization in endothelial cells of rabbit aortic valve following chronic nitroglycerine administration

长期服用硝酸甘油后兔主动脉瓣内皮细胞超极化减少

• 发表时间: 2005
• 期刊: Br J Phamacol 146
• 作者: Yasuma F;Hayano J;Mikito Kawamata et al.;Kamada Y;Kusama N et al.
• 通讯作者: Kusama N et al.

Development of method to measure intracellular concentrations of nitric oxide in endothelial cells of resistance arteries under ex vivo conditions

离体条件下测量阻力动脉内皮细胞一氧化氮浓度的方法开发

• 发表时间: 2004
• 期刊: The Journal of the Nagoya City University Medical Association 55
• 作者: M.Narita;H.Akai;T.Kita;Y.Nagumo;M.Narita;N.Sunagawa;C.Hara;K.Hasebe;H.Nagase;T.Suzuki;Tamao Yamamoto
• 通讯作者: Tamao Yamamoto

硝酸薬耐性 Update

耐硝酸盐更新

• 发表时间: 2004
• 作者: H.Ichikawa;T.Fujimoto;E.Taira;N.Miki;伊藤 猛雄
• 通讯作者: 伊藤 猛雄

Characteristics of attenuated endothelium-dependent relaxation seen in rabbit intrapulmonary vein following chronic nitroglycerine administration

长期服用硝酸甘油后兔肺内静脉内皮依赖性舒张减弱的特征

• 发表时间: 2005
• 期刊: Br J Pharmacol 145
• 作者: Uchida;Hiroshi;Kusama N
• 通讯作者: Kusama N

Characteristics of attenuated endothelium-dependent relaxation seen in rabbit intrapulmonary vein following chronic nitroglycerine administration.

长期服用硝酸甘油后，兔肺内静脉内皮依赖性舒张减弱的特征。

• 发表时间: 2005
• 期刊: Br J Pharmacol 145
• 作者: Kusama N;Kajikuri J;Watanabe Y;Suzuki Y;Katsuya H;Itoh T.
• 通讯作者: Itoh T.