Tomoda A, Murakami E, Shibuya T
Department of Biochemistry, Tokyo Medical College, Japan.
Artif Cells Blood Substit Immobil Biotechnol. 1997 Nov;25(6):501-9. doi: 10.3109/10731199709117447.
By using a nitric oxide (NO) selective electrode system. NO produced during the oxidation of human hemoglobin by nitrite was monitored. When 160 microM oxyhemoglobin (in heme) was reacted with 500 microM nitrite. NO was generated quickly at the initial lag phase of the oxidation of oxyhemoglobin by nitrite and decreased gradually during the second burst phase of the reaction. While the oxidation of oxyhemoglobin by nitrite proceeded in a sigmoidal manner including the initial lag phase and second burst phase. The maximal amount of NO produced under this condition was estimated to be 48 microM. According to the increase of nitrite concentrations added, the amounts of NO produced at the initial phase increased, being in good accordance with the increased rate of the oxidation of oxyhemoglobin. These results strongly suggest the critical role of NO in the oxidation mechanism of oxyhemoglobin by nitrite.
通过使用一氧化氮（NO）选择性电极系统，监测了亚硝酸盐氧化人血红蛋白过程中产生的NO。当160微摩尔（以血红素计）的氧合血红蛋白与500微摩尔亚硝酸盐反应时，在亚硝酸盐氧化氧合血红蛋白的初始延迟阶段迅速产生NO，并在反应的第二个爆发阶段逐渐减少。而亚硝酸盐氧化氧合血红蛋白以S形方式进行，包括初始延迟阶段和第二个爆发阶段。在此条件下产生的NO最大量估计为48微摩尔。随着添加的亚硝酸盐浓度增加，初始阶段产生的NO量增加，这与氧合血红蛋白氧化速率的增加非常一致。这些结果有力地表明了NO在亚硝酸盐氧化氧合血红蛋白机制中的关键作用。
