Reynolds J D, Zeballos G A, Penning D H, Kimura K A, Atkins B, Brien J F
Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
J Pharmacol Toxicol Methods. 1998 Apr;39(3):125-8. doi: 10.1016/s1056-8719(98)00007-0.
Pregnant sheep with a microdialysis probe implanted in the fetal cerebral cortex were used to determine if nitrate and nitrite anions (nitrate/nitrite) could be quantitated in the microdialysate as an indirect index of in vivo nitric oxide formation. Pregnant ewes (term, about 147 days) were surgically instrumented at gestational day (GD) 90 (n = 3; preterm) and GD 121 (n = 3; nearterm). Three days later, following an overnight probe equilibration period, five dialysate samples were collected continuously on ice at 1-h intervals (infusion rate of 1 (microl/min). The nitrate/nitrite concentration was determined by reducing a 10-microl aliquot of each dialysate fraction with hot acidic vanadium followed by chemiluminescence quantitation of the nitric oxide product. The lower limit of quantitative sensitivity of the method is 25 picomoles. Nitrate/nitrite concentration was 16.6+/-7.3 microM for the preterm fetus and 19.7+/-1.9 microM for the nearterm fetus. The data demonstrate that nitrate/nitrite, as an index of in vivo nitric oxide formation, can be quantitated in microdialysate samples collected from the intact fetal sheep cerebral cortex.
将微透析探针植入胎羊大脑皮层的妊娠绵羊被用于确定微透析液中硝酸根和亚硝酸根阴离子（硝酸盐/亚硝酸盐）是否可作为体内一氧化氮生成的间接指标进行定量分析。妊娠母羊（足月，约147天）在妊娠第90天（n = 3；早产）和第121天（n = 3；接近足月）接受手术植入仪器。三天后，经过一夜的探针平衡期，以1微升/分钟的输注速率，每隔1小时在冰上连续收集5份透析液样本。通过用热酸性钒还原每份10微升透析液部分，然后对一氧化氮产物进行化学发光定量分析来测定硝酸盐/亚硝酸盐浓度。该方法的定量灵敏度下限为25皮摩尔。早产胎儿的硝酸盐/亚硝酸盐浓度为16.6±7.3微摩尔/升，接近足月胎儿的为19.7±1.9微摩尔/升。数据表明，作为体内一氧化氮生成指标的硝酸盐/亚硝酸盐可在从完整胎羊大脑皮层收集的微透析液样本中进行定量分析。
