Bachi A, Zuccato E, Baraldi M, Fanelli R, Chiabrando C
Istituto di Ricerche Farmacologiche 'Mario Negri', Milano, Italy.
Free Radic Biol Med. 1996;20(4):619-24. doi: 10.1016/0891-5849(95)02087-x.
8-Epi-prostaglandin F2alpha (8-epi-PGF2alpha) is an F2-isoprostane recently identified as a marker of free radical-catalyzed lipid peroxidation in vivo and potential mediator of oxidative damage. Currently, endogenous 8-epi-PGF2alpha is measured by gas chromatography-mass spectrometry after lengthy sample preparation. We extracted and purified 8-epi-PGF2alpha in one step from biological samples on immunoaffinity columns prepared with an anti-8-epi-PGF2alpha antiserum, raised in our laboratory. Quantitation was done by stable-isotope dilution gas chromatography/negative-ion chemical ionization mass spectrometry, with selected ion recording. Carboxylate anions of the pentafluorobenzyl ester trimethylsilyl ether derivative of 8-epi-PGF2alpha and [2H4]8-epi-PGF2alpha were monitored (m/z 569 and 573). Basal urinary excretion of 8-epi-PGF2alpha can be accurately and rapidly measured by this method. Under normal conditions rats (n = 30) excreted 2.18 +/- 0.68 ng/24 h. In healthy nonsmoking young volunteers, urinary excretion of 8-epi-PGF2alpha, measured three times on alternate days, was fairly constant (CV 2-10%). Nonsmokers excreted significantly less 8-epi-PGF2alpha than age-matched smokers (8.08 +/- 2.3 vs. 18.40 +/- 4.77 ng/h/1.73 m2; n = 6; p < 0.005), as reported by others using different methods.
8-表-前列腺素F2α（8-epi-PGF2α）是一种F2-异前列腺素，最近被确定为体内自由基催化脂质过氧化的标志物以及氧化损伤的潜在介质。目前，内源性8-epi-PGF2α需经过冗长的样品制备后通过气相色谱-质谱法进行测定。我们在实验室制备的用抗8-epi-PGF2α抗血清制备的免疫亲和柱上一步从生物样品中提取并纯化8-epi-PGF2α。通过稳定同位素稀释气相色谱/负离子化学电离质谱法并采用选择离子记录进行定量。监测8-epi-PGF2α和[2H4]8-epi-PGF2α的五氟苄基酯三甲基硅醚衍生物的羧酸根阴离子（m/z 569和573）。通过该方法可准确快速地测定8-epi-PGF2α的基础尿排泄量。在正常条件下，大鼠（n = 30）的排泄量为2.18±0.68 ng/24 h。在健康不吸烟的年轻志愿者中，每隔一天测量三次8-epi-PGF2α的尿排泄量，结果相当稳定（CV 2-10%）。如其他人使用不同方法所报道的，不吸烟者排泄的8-epi-PGF2α明显少于年龄匹配的吸烟者（8.08±2.3与18.40±4.77 ng/h/1.73 m2；n = 6；p < 0.005）。
