Nitrite is an alternative source of NO in vivo.
Nitrite is an alternative source of NO in vivo.
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DOI：
10.1152/ajpheart.00525.2004
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发表时间：
2005-05
期刊：
影响因子：
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通讯作者：
K. Tsuchiya;Y. Kanematsu;M. Yoshizumi;Hideki Ohnishi;K. Kirima;Yuki Izawa;Michiyo Shikishima;T. Ishida;Shuji Kondo;S. Kagami;Y. Takiguchi;T. Tamaki
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文献类型：
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作者：
K. Tsuchiya;Y. Kanematsu;M. Yoshizumi;Hideki Ohnishi;K. Kirima;Yuki Izawa;Michiyo Shikishima;T. Ishida;Shuji Kondo;S. Kagami;Y. Takiguchi;T. Tamaki
在这项研究中，我们调查了口服给药的亚硝酸盐是否改变为NO，以及亚硝酸盐是否以剂量依赖性方式减轻高血压。我们利用[15N]亚硝酸盐（15NO2-）的稳定同位素作为亚硝酸盐的来源，以区分内源性亚硝酸盐和外源性管理和测量血红蛋白（Hb）-NO作为指标的循环NO在全血中使用电子顺磁共振（EPR）光谱。当大鼠口服1mg/kg Na_（15）NO_2时，血液中出现一个明显的由Hb_（15）NO（A（Z）= 23.4高斯）引起的EPR信号。对于1和3 mg/kg治疗，血液HbNO浓度峰值出现在摄入后第一次测量时（5分钟）（HbNO：分别为4.93 +/-0.52和10.58 +/-0.40 μ M），而对于10 mg/kg治疗，血液HbNO浓度峰值出现在摄入后第15分钟（HbNO：38.27 +/-9.23 μ M）。此外，与单独使用L-NAME（170 +/-13 mmHg）相比，联合使用亚硝酸盐（100 mg/l饮用水）和N（omega）-硝基-L-精氨酸甲酯（L-NAME; 1 g/l）3周可显著减轻L-NAME诱导的高血压（149 +/-10 mmHg）。此外，这种现象与循环HbNO的增加有关。我们的研究结果清楚地表明，口服摄入的亚硝酸盐可以替代L-精氨酸作为体内NO的来源，并可以解释，至少部分地，富含亚硝酸盐/硝酸盐的饮食方法来阻止高血压饮食诱导的肥胖效应的机制。
In this study, we investigated whether orally administered nitrite is changed to NO and whether nitrite attenuates hypertension in a dose-dependent manner. We utilized a stable isotope of [15N]nitrite (15NO2-) as a source of nitrite to distinguish between endogenous nitrite and that exogenously administered and measured hemoglobin (Hb)-NO as an index of circulating NO in whole blood using electron paramagnetic resonance (EPR) spectroscopy. When 1 mg/kg Na15NO2 was orally administered to rats, an apparent EPR signal derived from Hb15NO (A(Z) = 23.4 gauss) appeared in the blood. The peak blood HbNO concentration occurred at the first measurement after intake (5 min) for treatment with 1 and 3 mg/kg (HbNO: 4.93 +/- 0.52 and 10.58 +/- 0.40 microM, respectively) and at 15 min with 10 mg/kg (HbNO: 38.27 +/- 9.23 microM). In addition, coadministration of nitrite (100 mg/l drinking water) with N(omega)-nitro-L-arginine methyl ester (L-NAME; 1 g/l) for 3 wk significantly attenuated the L-NAME-induced hypertension (149 +/- 10 mmHg) compared with L-NAME alone (170 +/- 13 mmHg). Furthermore, this phenomenon was associated with an increase in circulating HbNO. Our findings clearly indicate that orally ingested nitrite can be an alternative to L-arginine as a source of NO in vivo and may explain, at least in part, the mechanism of the nitrite/nitrate-rich Dietary Approaches to Stop Hypertension diet-induced hypotensive effects.