Del Valle G O, Mosher M D, Conrad K P
Department of Physiology, University of New Mexico School of Medicine, Albuquerque 87131.
Am J Physiol. 1993 Aug;265(2 Pt 2):R399-403. doi: 10.1152/ajpregu.1993.265.2.R399.
Serum erythropoietin concentration increases during human pregnancy and presumably accounts for expansion of red blood cell mass. The mechanism(s) underlying gestational changes of serum erythropoietin are unknown. Moreover, if erythropoietin synthesis increases, then the organ(s) questions about erythropoietin in pregnancy, we first set out to establish an animal model. Chronically instrumented, conscious unrestrained rats were studied. 51Cr-labeled red blood cells and radioimmunoassay were used to assess red blood cell mass and serum erythropoietin, respectively. Except for a lower hematocrit (P < 0.05 vs. virgin rats) and a slightly higher plasma volume (P value not significant) for gravid rats on gestational day 6, all other variables measured in early pregnancy rats were comparable to those measured in virgin control animals. Significant increases in total blood volume, plasma volume, and red blood cell mass were observed by gestational day 13 (midpregnancy) when compared with virgin control rats. These changes were even more pronounced on gestational day 20. Serum immunoreactive erythropoietin was also significantly increased at both of these stages of pregnancy. We conclude that the gravid rat is a reliable animal model of human gestation in which to further investigate erythropoietin in pregnancy.
在人类孕期，血清促红细胞生成素浓度会升高，这可能是红细胞量增加的原因。血清促红细胞生成素孕期变化的潜在机制尚不清楚。此外，如果促红细胞生成素合成增加，那么合成器官是哪个（些）呢？关于孕期促红细胞生成素的问题，我们首先着手建立一个动物模型。我们研究了长期植入仪器的清醒自由活动大鼠。分别使用51Cr标记的红细胞和放射免疫分析法来评估红细胞量和血清促红细胞生成素。除了妊娠第6天的妊娠大鼠血细胞比容较低（与未孕大鼠相比，P < 0.05）以及血浆量略高（P值无统计学意义）外，早期妊娠大鼠测量的所有其他变量与未孕对照动物测量的变量相当。与未孕对照大鼠相比，在妊娠第13天（妊娠中期）观察到总血容量、血浆量和红细胞量显著增加。这些变化在妊娠第20天更为明显。在这两个孕期阶段，血清免疫反应性促红细胞生成素也显著增加。我们得出结论，妊娠大鼠是人类妊娠的可靠动物模型，可用于进一步研究孕期促红细胞生成素。
