A new method to measure nitrate/nitrite with a NO-sensitive electrode
A new method to measure nitrate/nitrite with a NO-sensitive electrode
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DOI：
10.1152/jappl.2001.90.1.317
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发表时间：
2001-01-01
影响因子：
3.3
通讯作者：
Roesen, R
中科院分区：
文献类型：
--
作者：
Berkels, R;Purol-Schnabel, S;Roesen, R
有不同的方法来测量不稳定的分子一氧化氮（NO）。我们将描述一种新的灵敏的方法来测量NO的硝酸盐/亚硝酸盐还原为NO，这将确定与电流型克拉克型电极。硝酸盐和亚硝酸盐是NO的降解产物。首先，硝酸盐通过硝酸还原酶被酶促转化为亚硝酸盐。其次，亚硝酸盐被酸性碘化物溶液还原至等摩尔NO浓度。电极在水溶液中的检测极限为2 nmol/l NO（意味着阈值取决于加入的体积：将500穆尔的0.2 μ mol/l亚硝酸盐溶液加入到10 ml浴中）。该方法提供了评估不同生物模型的基础和激动剂刺激的NO释放的能力。我们测量了猪冠状动脉和猪主动脉内皮细胞培养物中天然内皮细胞的基础和卡巴胆碱刺激的NO释放。而且，还可以测量硝酸盐！豚鼠心脏冠状流出液中的亚硝酸盐浓度。总之，我们提出了一个有效的，高灵敏度的新方法，测量亚硝酸盐/NO在生物系统中的市售电极。
There are different methods to measure the unstable molecule nitric oxide (NO). We will describe a new sensitive method to measure NO by reconversion of nitrate/nitrite to NO, which will be determined with an amperometric Clark-type electrode. Nitrate and nitrite are the degradation products of NO. First, nitrate is enzymatically converted to nitrite with the use of the nitrate reductase. Second, nitrite is reduced to equimolar NO concentrations by an acidic iodide solution. The detection limit of the electrode in an aqueous solution was 2 nmol/l NO (meaning the threshold was depending on the volume added: 500 mul of a 0.2 mu mol/l nitrite solution added to a 10-ml bath). This method provides the ability to assess basal and agonist-stimulated NO releases of different biological models. We measured basal and carbachol-stimulated NO release of native endothelial cells from porcine coronary arteries and porcine aortic endothelial cell cultures. Moreover, it was possible to measure the nitrate! nitrite concentration in the coronary effluent of a guinea pig heart. In conclusion, we present a valid, highly sensitive new method of measuring nitrite/NO in biological systems with a commercially available electrode.