A simple CO2 equilibration method for measuring blood oxygen isotope compositions
A simple CO2 equilibration method for measuring blood oxygen isotope compositions
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一种测量血氧同位素组成的简单 CO2 平衡方法
DOI：
10.1002/rcm.9256
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发表时间：
2022
影响因子：
2
通讯作者：
Colman Albert S.
中科院分区：
文献类型：
--
作者：
Green Daniel R.;Olack Gerard;Tutken Thomas;Leichliter Jennifer;Winkler Daniela E.;Clauss Marcus;Vonhof Hubert;Colman Albert S.
基本原理血液氧同位素组成可以为生理过程和生态模式提供有价值的见解。虽然血液样本通常出于医疗或科学目的而抽取，但很少测量血液成分中的氧同位素成分 (δ18O)，因为这种测量既耗时又昂贵。方法我们从野外和动物实验室饲养的绵羊、山羊和鬣蜥身上采集血液样本，放入医疗和科学研究中常用的血清、EDTA、肝素和无涂层塑料瓶中，然后分离红细胞 (RBC) 和血浆或血清血液成分。这些被注射到氦气冲洗的 Exetainer 管中，在那里它们自然地释放内源性二氧化碳（山羊血），或者注射到氦气和二氧化碳冲洗的管中（鬣蜥血）。在 GasBench II 系统上对 CO2 气体进行采样，并通过同位素比质谱仪 (IRMS) 测量 δ18O。结果 重复的 δ18O 测量在多天内保持稳定。在水标准中添加干燥的血液固体对其 δ18O 测量影响很小，这表明血清和血浆中的有机分子成分不会干扰血液 δ18O 值。我们观察到血浆、血清和红细胞组分之间存在轻微但具有统计学意义的 δ18O 偏移。鬣蜥的质量依赖性体内水分周转时间是从数据中得出的。结论我们证明，使用 GasBench 的简单血液 CO2 平衡方法可以快速、可靠且准确地表征哺乳动物和爬行动物血液样本的血浆、红细胞和全血部分中的水 δ18O（精度 ≤ 0.1‰）。该方法将扩大血液稳定同位素分析在生理和医学研究中的应用。
RationaleBlood water oxygen isotope compositions can provide valuable insights into physiological processes and ecological patterns. While blood samples are commonly drawn for medical or scientific purposes, blood fractions are infrequently measured for oxygen isotopic compositions (δ18O) because such measurements are time consuming and expensive.MethodsWe sampled blood from sheep, goats, and iguanas raised in field and animal laboratories into serum, EDTA, heparin, and uncoated plastic vials commonly used in medical and scientific research, then separated red blood cell (RBC) and plasma or serum blood fractions. These were injected into helium‐flushed Exetainer tubes where they naturally outgassed endogenous CO2(goat blood), or into He‐ and CO2‐flushed tubes (iguana blood). The CO2gas was sampled on a GasBench II system, and δ18O was measured by an isotope ratio mass spectrometer (IRMS).ResultsRepeated δ18O measurements were stable over multiple days. The addition of desiccated blood solids to water standards had little impact on their δ18O measurements, suggesting that organic molecular constituents within blood serum and plasma do not interfere with blood water δ18O values. We observed slight but statistically significant δ18O offsets between plasma, serum and RBC fractions. Mass‐dependent body water turnover times for iguanas were derived from the data.ConclusionsWe demonstrate that a simple blood‐CO2equilibration method using the GasBench can quickly, reliably and accurately characterize water δ18O in the plasma, RBC, and whole blood fractions of mammalian and reptilian blood samples (precision ≤ 0.1‰). This method will expand the application of blood stable isotope analysis in physiological and medical research.