Santa Casa de Belo Horizonte, Núcleo de Pós-Graduação, Av. Francisco Sales, 1111, 30150-221, Belo Horizonte, MG, Brazil.
Free Radic Biol Med. 2010 Aug 1;49(3):493-500. doi: 10.1016/j.freeradbiomed.2010.05.012. Epub 2010 May 25.
Contrasting with increased nitric oxide (NO) formation during healthy pregnancy, reduced NO bioavailability plays a role in preeclampsia. However, no study has examined whether increased NO consumption by enhanced circulating levels of cell-free hemoglobin plays a role in preeclampsia. We studied 82 pregnant women (38 healthy pregnant and 44 with preeclampsia). To assess NO bioavailability, we measured plasma and whole blood nitrite concentrations using an ozone-based chemiluminescence assay. Plasma ceruloplasmin concentrations and plasma NO consumption (pNOc) were assessed and plasma hemoglobin (pHb) concentrations were measured with a commercial immunoassay. We found lower whole blood and plasma nitrite concentrations in preeclamptic patients (-48 and -39%, respectively; both P<0.05) compared with healthy pregnant women. Plasma samples from preeclamptic women consumed 63% more NO (P=0.003) and had 53% higher pHb and 10% higher ceruloplasmin levels than those found in healthy pregnant women (P<0.01). We found significant positive correlations between pHb and pNOc (r=0.61; P<0.0001), negative correlations between pNOc and whole blood or plasma nitrite concentrations (P=0.02; r=-0.32 and P=0.01; r=-0.34, respectively), and negative correlations between pHb and whole blood or plasma nitrite concentrations (P=0.03; r=-0.36 and P=0.01; r=-0.38, respectively). These findings suggest that increased pHb levels lead to increased NO consumption and lower NO bioavailability in preeclamptic compared with healthy pregnant women.
与健康妊娠期间一氧化氮（NO）形成增加形成对比的是，NO 生物利用度降低在子痫前期中起作用。然而，尚无研究探讨循环无细胞血红蛋白水平升高导致的 NO 消耗增加是否在子痫前期中起作用。我们研究了 82 名孕妇（38 名健康孕妇和 44 名子痫前期孕妇）。为了评估 NO 生物利用度，我们使用基于臭氧的化学发光测定法测量血浆和全血中亚硝酸盐浓度。评估血浆铜蓝蛋白浓度和血浆一氧化氮消耗（pNOc），并使用商业免疫测定法测量血浆血红蛋白（pHb）浓度。我们发现子痫前期患者的全血和血浆中亚硝酸盐浓度均降低（分别为-48%和-39%；均 P<0.05），与健康孕妇相比。与健康孕妇相比，子痫前期妇女的血浆样本消耗的 NO 多 63%（P=0.003），pHb 高 53%，铜蓝蛋白高 10%（均 P<0.01）。我们发现 pHb 与 pNOc 之间存在显著正相关（r=0.61；P<0.0001），pNOc 与全血或血浆中亚硝酸盐浓度之间存在负相关（P=0.02；r=-0.32 和 P=0.01；r=-0.34，分别），pHb 与全血或血浆中亚硝酸盐浓度之间存在负相关（P=0.03；r=-0.36 和 P=0.01；r=-0.38，分别）。这些发现表明，与健康孕妇相比，子痫前期患者的 pHb 水平升高导致 NO 消耗增加和 NO 生物利用度降低。
