Oxygen uptake during the mixing of saliva with ascorbic acid under acidic conditions: possibility of its occurrence in the stomach

FEBS Letters

Hirota, Sachiko²  Takahama, Umeo¹  Oniki, Takayuki¹  Yamamoto, Ayumi¹ 

[1] Kyushu Dental University, Kitakyushu 803-8580, Japan;Department of Nutritional Science, Kyushu Women's University, Kitakyushu 807-8586, Japan

关键词: Ascorbic acid;    Gastric juice;    Nitric oxide;    Nitrite;    Oxygen uptake;    Saliva;    AA;    ascorbic acid;    DTCS;    N-(dithiocarboxy)sarcosine sodium disalt;    ESR;    electron spin resonance;   

DOI  :  10.1016/S0014-5793(03)00820-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Human saliva, which contains nitrite, is normally mixed with gastric juice, which contains ascorbic acid (AA). When saliva was mixed with an acidic buffer in the presence of 0.1 mM AA, rapid nitric oxide formation and oxygen uptake were observed. The oxygen uptake was due to the oxidation of nitric oxide, which was formed by AA-dependent reduction of nitrite under acidic conditions, by molecular oxygen. A salivary component SCN⁻ enhanced the nitric oxide formation and oxygen uptake by the AA/nitrite system. The oxygen uptake by the AA/nitrite/SCN⁻ system was also observed in an acidic buffer solution. These results suggest that oxygen is normally taken up in the stomach when saliva and gastric juice are mixed.

【 授权许可】

Unknown