Nitrite anion (NO₂⁻) is a circulating nitric oxide (NO) metabolite considered an endothelial function marker. Nitrite can be produced from nitrate (NO₃⁻) secreted from plasma into saliva. The nitrate reductase of oral bacteria converts salivary nitrate to nitrite, which is swallowed and absorbed into circulation. In this study, we aimed to examine the relevance between these species' salivary and blood levels. We collected three whole saliva samples (unstimulated, paraffin-stimulated, and post-chlorhexidine mouthwash stimulated saliva) and blood from 75 healthy volunteers. We measured the nitrite and nitrate by the chemiluminescence method. The nitrite levels in stimulated saliva and post-mouthwash stimulated saliva exhibited weak correlations with blood nitrite. There was no correlation between nitrite in unstimulated saliva with blood nitrite. The baseline platelet activity, determined as P-selectin expression, negatively correlated with nitrite in plasma and post-mouthwash stimulated saliva. The salivary nitrate in all saliva samples showed correlations with its plasma levels. We conclude that nitrite in stimulated saliva correlates with blood nitrite.

亚硝酸根阴离子 (NO ₂ ^- ) 是循环的一氧化氮 (NO) 代谢物，被认为是内皮功能标志物。亚硝酸盐可以从硝酸盐（NO ₃ ^-) 从血浆分泌到唾液中。口腔细菌的硝酸盐还原酶将唾液中的硝酸盐转化为亚硝酸盐，亚硝酸盐被吞咽并吸收到循环中。在这项研究中，我们旨在检查这些物种的唾液和血液水平之间的相关性。我们从 75 名健康志愿者那里收集了三个完整的唾液样本（未刺激的、石蜡刺激的和洗必泰后漱口水刺激的唾液）和血液。我们通过化学发光法测量了亚硝酸盐和硝酸盐。刺激唾液和漱口后刺激唾液中的亚硝酸盐水平与血液亚硝酸盐呈弱相关性。未刺激唾液中亚硝酸盐与血亚硝酸盐无相关性。基线血小板活性，确定为 P-选择素表达，与血浆中的亚硝酸盐和漱口后刺激的唾液呈负相关。所有唾液样本中的唾液硝酸盐都与其血浆水平相关。我们得出结论，刺激唾液中的亚硝酸盐与血液亚硝酸盐相关。