硝酸盐还原酶还原─比色法测定一氧化氮代谢产物

Determination of nitric Oxide metabolites with nitrate reductase

为测定体液中的一氧化氮代谢产物（硝酸盐／亚硝酸盐，NO／NO），建立了一种采用硝酸盐还原酶还原一比色测定NO／NO的方法。该法的原理为硝酸盐还原酶将硝酸盐还原成亚硝酸盐，后者与对氨基苯磺酸发生重氮反应，并与α-萘胺偶联显色。检测灵敏度为3．5μmol／L，100μmol／L以内线性良好，还原率为96．8％，平均回收率为99．3％，批内、批间变异系数分别为3.22％和5.20％。该法无需除蛋白，还原率和灵敏度高，操作简单，反应时间短，是检测生物体液标本中一氧化氮代谢产物较理想的方法。

To determine nitrite oxide metabolites (nitrate/ nitrite) in biological fluids, we use nitrate reductase as catalyst to reduce nitrate. Nitrite is determined by Griess reaction. Analytic indeces of the method are following: linearity 10~100μmol/L, detection limit 3.5 μmol/L, reduction ratio 96. 8%, mean recovery 99, 3%, intra -run CV 3. 22%, inter-run Ch 5. 20%. With no deproteinization,high reduction ratio and precision, it may be useful to determine nitric oxide metabolites in biological fluid.