McMullen J R, Gibson K J, Lumbers E R
School of Physiology and Pharmacology, University of New South Wales, Sydney, Australia.
Biol Neonate. 1998;73(4):254-63. doi: 10.1159/000013984.
To determine the effects of circulating noradrenaline on fetal renal function noradrenaline was infused intravenously into 7 chronically catheterised fetal sheep (127-138 days) at a dose (1 microgram/kg/min) which resulted in plasma levels similar to those which occur during hypoxia. Fetal mean arterial pressure increased by approximately 14 mmHg (p < 0.001) and haematocrit rose (p < 0.005). Glomerular filtration rate rose from 3.85 +/- 0.47 (SEM) to 4.70 +/- 0.50 ml/min (p < 0.05) during the first hour and fractional reabsorption of sodium by the proximal tubule fell (p < 0.05) during the second hour. Urine flow rate increased from 0.61 +/- 0.13 to 1.18 +/- 0.24 ml/min (p < 0.001) and osmolar excretion increased from 78 +/- 15 to 153 +/- 36 mu osm/min (p < 0.005). By contrast lung liquid flow fell (p < 0.05), but the increase in urine flow was much greater than the decline in lung liquid. These findings suggest that during hypoxia, noradrenaline may play an important role in the maintenance of urine flow and consequently amniotic fluid volume and, as suggested by others, in the distribution of fluid between the vascular and interstitial compartments.
为了确定循环中的去甲肾上腺素对胎儿肾功能的影响，将去甲肾上腺素以1微克/千克/分钟的剂量静脉注入7只慢性插管的胎羊（妊娠127 - 138天）体内，该剂量导致的血浆水平与缺氧时出现的水平相似。胎儿平均动脉压升高约14 mmHg（p < 0.001），血细胞比容升高（p < 0.005）。在第一个小时内，肾小球滤过率从3.85±0.47（标准误）升至4.70±0.50毫升/分钟（p < 0.05），近端小管对钠的分数重吸收在第二个小时下降（p < 0.05）。尿流率从0.61±0.13升至1.18±0.24毫升/分钟（p < 0.001），渗透排泄量从78±15升至153±36微渗量/分钟（p < 0.005）。相比之下，肺液流量下降（p < 0.05），但尿流的增加远大于肺液流量的下降。这些发现表明，在缺氧期间，去甲肾上腺素可能在维持尿流以及羊水容量方面发挥重要作用，并且正如其他人所指出的，在血管和间质腔室之间的液体分布中也发挥重要作用。
