MONITORING UREAGENESIS IN PATIENTS WITH OTC DEFICIENCY

我们开发了一种新的技术，用于监测女性鸟氨酸转氨酶缺乏症(OTC)杂合子的代谢能力。我们的方法使用质谱仪来测量口服15NH4C l后4小时内15NH_4C_1到(15N)尿素和(5-15N)谷氨酰胺的转化。我们发现，无症状杂合子转化为尿素的NH3氮显著减少。因此，有症状的杂合子的血液中的(15N)尿素浓度(Mm)在大多数情况下都显著低于对照组。无症状杂合子和有症状杂合子患者的(5-15N)谷氨酰胺(MM)血浓度均显著高于对照组。给对照组注射试验剂量的苯丁酸钠并不影响(15N)尿素的形成。

We have developed a novel technique for monitoring metabolic competency in female heterozygotes for ornithine transcarbamylase deficiency (OTC). Our method uses mass spectrometry to measure the conversion of 15NH4C1 to (15N) urea and (5-15N) glutamine during a 4 hour period following an oral 15NH4C1 load (25.9 mmol). We found that asymptomatic heterozygotes converted significantly less NH3 nitrogen to urea. Thus, the (15N) urea concentration (mM) in the blood of symptomatic heterzygotes was significantly less than control values at most points. The blood concentration of (5-15N) glutamine (mM) was significantly higher in both asymptomatic and symptomatic heterozygotes than it was in the control subjects. The administration of a test dose of sodium phenylbutyrate to the control group did not affect the rate of (15N) urea formation.