Matsuo M, Morikawa Y, Hashimoto Y, Baratz R S
Exp Pathol. 1986;30(4):203-8. doi: 10.1016/s0232-1513(86)80078-0.
Bilateral ureteral ligation changes the blood urea nitrogen (BUN) concentration in pregnant and non-pregnant rats. Marked increases of the BUN concentration occurred in both pregnant and non-pregnant specimens after ligation. The BUN concentration in sham-ligated rats did not change from day 16 through 19 of pregnancy, but increased on day 20 of pregnancy and thereafter. There was no significant difference in BUN between ligated pregnant rats on days 16 and 17 of pregnancy and ligated non-pregnant rats. As pregnancy progressed from day 18 onward, the BUN in ligated pregnant rats decreased when compared with that of ligated non-pregnant rats, but did not reach the level in sham-ligated pregnant rats. The BUN of mothers and fetuses both in the ligated and the sham-ligated groups were similar. Amniotic fluid urea nitrogen levels were higher than in blood on late fetal days. In ligated mothers, a significant relationship between maternal BUN and the number of fetuses was noted on day 22 of pregnancy. These results suggest that the fetal kidney becomes functional for excreting urea in late fetal life.
双侧输尿管结扎会改变妊娠和未妊娠大鼠的血尿素氮（BUN）浓度。结扎后，妊娠和未妊娠标本中的BUN浓度均显著升高。假结扎大鼠的BUN浓度在妊娠第16天至19天没有变化，但在妊娠第20天及之后升高。妊娠第16天和17天的结扎妊娠大鼠与结扎未妊娠大鼠的BUN没有显著差异。随着妊娠从第18天开始进展，与结扎未妊娠大鼠相比，结扎妊娠大鼠的BUN下降，但未达到假结扎妊娠大鼠的水平。结扎组和假结扎组的母体和胎儿的BUN相似。在胎儿后期，羊水尿素氮水平高于血液中的水平。在结扎的母体中，妊娠第22天母体BUN与胎儿数量之间存在显著关系。这些结果表明，胎儿肾脏在胎儿后期开始发挥排泄尿素的功能。
