DETERMINATION OF ENDOGENOUSLY PRODUCED NITRIC OXIDE (NO) IN RAT STOMACH : CYTOPROTECTIVE ROLE OF NO

大鼠胃内源性一氧化氮 (NO) 的测定：NO 的细胞保护作用

• 批准号: 11470497
• 负责人: YOSHIMURA Tetsuhiko
• 金额: $ 6.98万
• 依托单位: INSTITUTE FOR LIFE SUPPORT TECHNOLOGY (ILST), YAMAGATA PUBLIC CORPORATION FOR THE DEVELOPMENT OF INDUSTRY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 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/en/grant/KAKENHI-PROJECT-11470497/
• 关键词: NITRIC OXIDE; ENDOGENOUSLY PRODUCED NITRIC OXIDE; NO IN STOMACH; CHAMBERED STOMACH; NITRITE; NITRATE; S-NITROSOTHIOL; DINITROSYL DITHIOLATO IRON COMPLEX; チャンバード・スタマック法; チャンバート・スタマック法

Nitric oxide (NO) is biologically synthesized in stomach by three forms of nitric oxide synthase (NOS). Nitrite in saliva derived from dietary nitrate is chemically reduced to NO under the acidic conditions in the stomach. Thus, gastrointestinal tracts are highly exposed to NO derived from both endogenous and exogenous origins. Recently, endogenously synthesized NO in stomach has been demonstrated to exert physiological and pathophysiological effects on gastric mucosal blood flow, acid and mucus secretion, gastric motility, and regulates mucosal defense and injury. In this study we investigated the roles of NO on ethanol-induced gastric mucosal injury in rats. Under urethane anesthesia, a rat stomach was mounted on an ex vivo chamber ; saline and then aqueous ethanol (43%) solutions were perfused. NO production in stomach tissues was analyzed by spin trapping technique combined with electron paramagnetic resonance spectroscopy. Nitrite and nitrate (NOx) in the luminal fluid were determined by the Griess-reaction assay with HPLC.Gastric mucosal blood flow, luminal pH, gastric mucosal potential difference, and area of the macroscopic mucosal injury were evaluated with/without preadministration of NOS inhibitor, N^G-nitro-L-arginine methyl ester (L-NAME). Preadministration of L-NAME aggravated mucosal damage and suppressed increase of mucosal blood flow. In conclusion, endogenously produced NO plays an important role in the protection against ethanol-induced gastric injury via regulation of gastric mucosal blood flow. Further, we investigated the physiological activities and in vivo distribution of dinitrosyl dithiolato iron complex (DNIC), which has been recognized as one of endogenous NO donor molecules. A combination of ex vivo and in vivo EPR spectrometry made it possible to reveal that DNIC not only possesses an excellent membrane-permeability but also has a markedly high affinity for the liver and kidney.

一氧化氮 (NO) 在胃中由三种形式的一氧化氮合酶 (NOS) 生物合成。唾液中源自膳食硝酸盐的亚硝酸盐在胃的酸性条件下化学还原为一氧化氮。因此，胃肠道高度暴露于源自内源性和外源性的NO。近年来，胃内源合成的NO对胃粘膜血流、胃酸和粘液分泌、胃动力以及调节粘膜防御和损伤等具有生理和病理生理作用。在本研究中，我们研究了 NO 在乙醇诱导的大鼠胃粘膜损伤中的作用。在聚氨酯麻醉下，将大鼠胃安装在离体室上；依次灌注盐水和乙醇水溶液(43%)。通过自旋捕获技术结合电子顺磁共振波谱分析胃组织中 NO 的产生。通过 HPLC 进行格里斯反应测定管腔液中的亚硝酸盐和硝酸盐 (NOx)。在预先给予/不给予 NOS 抑制剂的情况下评估胃粘膜血流量、管腔 pH 值、胃粘膜电位差和宏观粘膜损伤面积, N^G-硝基-L-精氨酸甲酯（L-NAME）。预先给予L-NAME会加重粘膜损伤并抑制粘膜血流量的增加。总之，内源性NO通过调节胃粘膜血流在防止乙醇引起的胃损伤中发挥重要作用。此外，我们还研究了二亚硝基二硫醇铁络合物（DNIC）的生理活性和体内分布，该络合物已被认为是内源性NO供体分子之一。离体和体内 EPR 光谱分析的结合表明，DNIC 不仅具有优异的膜渗透性，而且对肝脏和肾脏具有显着高的亲和力。

项目成果

藤井敏司: "A new trend in iron-dithiocarbamate complexes : as an endogenous NO trapping"Coordination Chemistry Reviews. 198. 89-99 (2000)

Satoshi Fujii：“铁-二硫代氨基甲酸盐复合物的新趋势：作为内源性 NO 捕获”《协调化学评论》198. 89-99 (2000)。

S.Fujii, K.Kobayashi, S.Tagawa, T.Yoshimura: "Reaction of nitric oxide with iron (III) complex of N-(dithiocarboxy)sarcosine : A New type of reductive nitrosylation involving the iron (IV) as an intermediate"J.Chem.Soc.Dalton Trans.. 3310-3315 (2000)

S.Fujii、K.Kobayashi、S.Takawa、T.Yoshimura：“一氧化氮与 N-(二硫羧基)肌氨酸铁 (III) 络合物的反应：一种涉及铁 (IV) 作为中间体的新型还原亚硝基化反应

菅田英明: "エタノール胃粘膜損傷(ラット)におけるNO測定とNOの生理作用"磁気共鳴と医学. 12(印刷中). (2001)

Hideaki Suda：“NO 测量和 NO 对乙醇胃粘膜损伤（大鼠）的生理影响”《磁共振与医学》12（出版中）。

上野孝治: "内因性NO・チオレート鉄錯体のNO基供与性に関するEPRによる検討"磁気共鳴と医学. 11. 83-86 (2000)

Koji Ueno：“内源性 NO 和硫醇铁复合物的 NO 基团供给特性的 EPR 研究”《磁共振与医学》11. 83-86 (2000)。

菅田英明: "エタノール胃粘膜損傷(ラット)におけるNO測定とNOの生理作用"磁気共鳴と医学. (印刷中). (2001)

Hideaki Suda：“一氧化氮测量和一氧化氮对乙醇胃粘膜损伤（大鼠）的生理影响”磁共振与医学（2001 年出版）。