Ranta V, Viinikka L, Halmesmäki E, Ylikorkala O
Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Finland.
Obstet Gynecol. 1999 Mar;93(3):442-5. doi: 10.1016/s0029-7844(98)00465-7.
To clarify production of nitric oxide with pre-eclampsia.
Production of nitric oxide and elimination of its metabolites, nitrite and nitrate, determines ultimately the level of those metabolites in plasma of subjects whose diets lack them. We measured simultaneously plasma levels and renal clearance of nitrite and nitrate in 20 women with preeclampsia and in 21 healthy pregnant women. Fifteen preeclamptic gravidas were receiving antihypertensive medication and five received betamethasone 1-4 days before the study. Subjects were prescribed low nitrite and nitrate diets for 24 hours and fasted overnight before collection of plasma and urine samples. Nitrite and nitrate were measured spectrophotometrically by Griess reaction.
Preeclamptic women had significantly higher plasma levels of nitrite and nitrate (18.1+/-6.2 micromol/L versus 13.0+/-4.3 micromol/L, mean+/-standard deviation [SD], P = .009), which because renal clearance did not differ (0.6+/-0.3 versus 0.7+/-0.3 mL/s), indicated increased production of nitric oxide with preeclampsia that was unaffected by antihypertensives or betamethasone. The mean plasma level of endothelin-1 was increased (5.1+/-1.4 versus 3.6+/-1.0 pg/mL, P < .001), and urinary output of the prostacyclin metabolite 2,3-dinor-6-keto-prostaglandin F1alpha was decreased (39.1+/-18.0 versus 61.3+/-35.6 ng/mmol creatinine, P = .019) with preeclampsia. These two endothelial markers showed no relation to plasma nitrite and nitrate.
Nitric oxide production was increased with preeclampsia. The biologic significance of increased production is unknown, but it might be compensation for the vasoconstriction of preeclampsia.
明确子痫前期患者一氧化氮的生成情况。
一氧化氮的生成及其代谢产物亚硝酸盐和硝酸盐的清除最终决定了饮食中缺乏这些物质的受试者血浆中这些代谢产物的水平。我们同时测量了20例子痫前期患者和21例健康孕妇血浆中亚硝酸盐和硝酸盐的水平以及肾脏对它们的清除率。15例子痫前期孕妇在研究前正在接受抗高血压药物治疗，5例在研究前1 - 4天接受了倍他米松治疗。受试者在收集血浆和尿液样本前24小时食用低亚硝酸盐和硝酸盐饮食，并禁食过夜。通过格里斯反应分光光度法测量亚硝酸盐和硝酸盐。
子痫前期患者血浆中亚硝酸盐和硝酸盐水平显著升高（18.1±6.2微摩尔/升对13.0±4.3微摩尔/升，均值±标准差[SD]，P = 0.009），由于肾脏清除率无差异（0.6±0.3对0.7±0.3毫升/秒），这表明子痫前期患者一氧化氮生成增加，且不受抗高血压药物或倍他米松的影响。子痫前期患者内皮素 - 1的平均血浆水平升高（5.1±1.4对3.6±1.0皮克/毫升，P < 0.001），前列环素代谢产物2,3 - 二去甲 - 6 - 酮 - 前列腺素F1α的尿量减少（39.1±18.0对61.3±35.6纳克/毫摩尔肌酐，P = 0.019）。这两种内皮标志物与血浆亚硝酸盐和硝酸盐无相关性。
子痫前期患者一氧化氮生成增加。生成增加的生物学意义尚不清楚，但可能是子痫前期血管收缩的一种代偿机制。
