Jóźwik Maciej, Jóźwik Marcin, Pietrzycki Bartosz, Chojnowski Marcin, Teng Cecilia, Jóźwik Michał, Battaglia Frederick C
Department of Gynecology, Medical University of Białystok, Białystok, Poland.
Biol Neonate. 2005;87(1):38-43. doi: 10.1159/000081702. Epub 2004 Oct 26.
The current evidence on the primary source of ammonia production in the human fetoplacental unit is potentially misleading.
The aim of the present investigation was to determine the concentration of ammonia in human maternal and fetal blood at birth and to compare them with published data in late gestation sheep.
In 12 normal human pregnancies, umbilical arterial and venous and maternal venous blood was sampled, and whole blood ammonia concentrations were measured. Data from 12 pregnant sheep and fetuses from our previous studies were utilized for comparison.
The human fetus at delivery has higher concentrations of ammonia (60-80 microM) than the late gestation fetal lamb (25-35 microM). In the human, the arterial umbilical ammonia concentration exceeds the venous umbilical concentration, indicating a net ammonia production by fetal tissues. In sheep, the venous umbilical ammonia concentration exceeds the arterial umbilical concentration, indicating the net placental ammonia production.
In contrast to fetal lambs, human fetuses exhibit a net production of ammonia, which may reflect differences in biologic state or a species difference.
目前关于人类胎儿 - 胎盘单位中氨产生主要来源的证据可能具有误导性。
本研究的目的是测定出生时人类母体和胎儿血液中的氨浓度，并将其与妊娠晚期绵羊已发表的数据进行比较。
在12例正常人类妊娠中，采集脐动脉、脐静脉和母体静脉血，测量全血氨浓度。利用我们之前研究中的12只妊娠绵羊和胎儿的数据进行比较。
分娩时人类胎儿的氨浓度（60 - 80微摩尔/升）高于妊娠晚期的胎羊（25 - 35微摩尔/升）。在人类中，脐动脉氨浓度超过脐静脉浓度，表明胎儿组织有净氨生成。在绵羊中，脐静脉氨浓度超过脐动脉浓度，表明胎盘有净氨生成。
与胎羊不同，人类胎儿表现出氨的净生成，这可能反映了生物状态的差异或物种差异。
