Neopterin (NP), biopterin (BP) and monapterin (MP) exist in saliva. The physiological role of salivary NP as well as the pathophysiological role of increased NP in the immune-activated state has been unclear. Saliva is a characteristic specimen different from other body fluids. In this study, we analysed salivary NP and related pterin compounds, BP and MP and revealed some of its feature. High-performance liquid chromatography (HPLC) analysis of saliva and plasma obtained from 26 volunteers revealed that salivary NP existed mostly in its fully oxidized form. The results suggested that salivary NP as well as BP would mostly originate from the oral cavity, perhaps the salivary glands, and that salivary NP levels might not reflect those in the plasma. We also found that a gender difference existed in correlations between concentrations of salivary total concentrations of NP (tNP) and BP (tBP). HPLC analysis of saliva obtained from 5 volunteers revealed that the concentrations of salivary tNP as well as tBP fluctuated in an irregular fashion in various individuals. MP, a diastereomer of NP, might have come from oral cavity NP itself or its precursor. These results indicated that the nature of salivary NP might be different from that of NP in the blood or urine.

中文翻译：

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唾液中的新蝶呤和相关蝶呤：它们与血浆中的比较以及个体的变化

唾液中存在新蝶呤（NP）、生物蝶呤（BP）和单蝶呤（MP）。唾液 NP 的生理作用以及免疫激活状态下增加的 NP 的病理生理作用尚不清楚。唾液是不同于其他体液的特征性标本。在这项研究中，我们分析了唾液 NP 和相关的蝶呤化合物、BP 和 MP，并揭示了它的一些特征。对 26 名志愿者的唾液和血浆进行的高效液相色谱 (HPLC) 分析表明，唾液 NP 主要以完全氧化的形式存在。结果表明，唾液 NP 和 BP 主要来自口腔，可能是唾液腺，唾液 NP 水平可能无法反映血浆中的水平。我们还发现，唾液中 NP (tNP) 和 BP (tBP) 总浓度的相关性存在性别差异。从 5 名志愿者获得的唾液的 HPLC 分析显示，唾液 tNP 和 tBP 的浓度在不同个体中以不规则的方式波动。MP是NP的非对映异构体，可能来自口腔NP本身或其前体。这些结果表明唾液NP的性质可能与血液或尿液中NP的性质不同。