Elucidation of the formation pathways of nitric oxide involved in the reduction of orally-ingested nitrite in vivo

在本研究中，我们在体内研究了槲皮素和铁（II）等还原剂是否促进口服亚硝酸盐生成一氧化氮（NO）气体。大鼠口服3 mg/kg Na^<15>NO_2时，亚硝酸盐或亚硝酸盐加槲皮素处理后血中出现Hb^<15>NO，表明全身（15）^NO，且达到Hb^<15>N0血药浓度最大值的时间为15 min，而亚硝酸盐加铁（II）或亚硝酸盐加铁（II）加槲皮素使时间缩短（10 min）。有趣的是，无论是铁（II）、槲皮素，还是铁（II）加槲皮素，都不影响口服Na^<15>NO_2产生的Hb^<15>NO的总量。然而，在铁（II）或铁（II）加槲皮素的存在下，全身亚硝酸盐浓度显著降低。这些结果可能表明，在我们的实验条件下，铁（II）对亚硝酸盐生成NO气体至关重要，而槲皮素在体内的贡献很小。

In this research, we investigated whether reducing agents such as quercetin and iron(II) facilitate nitric oxide (NO) gas formation from orally ingested nitrite in vivo study. When 3 mg/kg Na^<15>NO_2 was orally administered to rats with or without iron(II) or quercetin, Hb^<15>NO, which is indicative of systemic (15)^NO, was appeared in the blood, and the time to maximum blood concentration of Hb^<15>N0 was 15 min after nitrite or nitrite plus quercetin treatment, whereas nitrite plus iron(II) or nitrite plus iron(II) with quercetin shortened the time (10 min). Interestingly either iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb^<15>NO generated from orally administered Na^<15>NO_2. However, systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is of critical importance to the generation of NO gas from nitrite, whereas quercetin provides little contribution in vivo under our experimental conditions.