METABOLISM OF 8 EPI PGF2 IN HEALTHY VOLUNTEERS

在过去的十年中，各种各样的病理条件已被链接到氧化应激和研究在这一领域已经经历了巨大的增长。然而，氧化应激在人类疾病发病机制中所起的作用仍然不清楚，主要是由于目前评估体内氧化应激的方法的局限性。Morrow等人发现了一系列由花生四烯酸的非酶自由基催化过氧化反应产生的类野牡丹素化合物。这些异前列烷由花生四烯酸酯化成磷脂原位形成，并且一旦以游离形式释放，就能够具有生物活性。 异前列烷似乎是体内氧化损伤的可靠标志物。 然而，花生四烯酸的自动氧化可能导致血浆中异前列烷的人为增加，并且在更有限的程度上，导致尿液中异前列烷的人为增加。 尿中异前列烷酶代谢产物的测量将克服这一问题，并将提供一个可靠的，非侵入性的和综合指标的氧化应激在体内。 异前列烷8-epi-PGF（2a）的主要尿代谢产物最近被鉴定为2，3-二去甲-5，6-二氢-8-epi PGF（2a）。 我们现在已经开发了气相色谱/负离子化学电离-质谱（GC/NICI-MS）技术，使我们能够定量具体的尿排泄的8-表PGF（2a）。 我们现在建议在5名健康志愿者中评估在输注增加剂量的8-epi PGF（2a）后这些化合物的尿排泄。 此外，我们拥有电喷雾质谱和技术专长，可以尝试鉴定输注的8-epi-PGF（2a）的极性代谢产物。

Over the past ten years a wide variety of pathological conditions has been linked to oxidative stress and research in this field has undergone a tremendous growth. However, the role played by oxidative stress in the pathogenesis of human diseases is still unclear mainly due to limitation of current methodology to assess oxidant stress in vivo. Morrow et al. have discovered a series of prostaglandin-like compounds that are produced by nonenzymatic free radical catalyzed peroxidation of arachidonic acid. These isoprostanes are formed in situ from arachidonic acid esterified to phospholipids and, once released in free form, are capable of biological activity. The isoprostanes appear to be reliable markers of oxidant injury in vivo. However, auto-oxidation of arachidonic acid may lead to artifactual increase of isoprostanes in plasma and, to a more limited degree, in urine. The measurement of urinary enzymatic metabolites of the isoprostanes would overcome this problem and would provide a reliable, non-invasive and integrated index of oxidant stress in vivo. The major urinary metabolite of the isoprostane 8-epi-PGF(2a) has been recently identified as the 2,3-dinor-5,6-dihydro-8-epi PGF(2a). We have now developed gas chromatography/negative ion chemical ionization-mass spectrometry (GC/NICI-MS) techniques that enable us to quantiate specifically the urinary excretion of both 8-epi PGF(2a). We now propose to assess the urinary excretion of these compounds following infusion of increasing doses of 8-epi PGF(2a) in five healthy volunteers. In addition, we have an electrospray mass spectrometry and the technical expertise to attempt the identification of polar metabolites of infused 8-epi-PGF(2a).