Zanjani E D, Pixley J S, Slotnick N, MacKintosh F R, Ekhterae D, Clemons G
Department of Veterans Affairs Medical Center, University of Nevada School of Medicine, Reno.
Pathobiology. 1993;61(3-4):211-5. doi: 10.1159/000163796.
Erythropoiesis in the fetus is controlled by erythropoietin (Ep). To determine the role of maternal Ep in this process, we used catheterized preparations of sheep and monkey fetuses to assess the ability of Ep administered to the mother to cross the placental barrier into the fetus. Ep was injected into pregnant sheep (3,600 IU/sheep) or monkeys (800-2,000 IU/animal) as a single intravenous dose, or into sheep in intravenous doses of 2,000 IU once every 12 h for a total of 4 injections. Maternal and fetal blood samples for Ep and reticulocyte determinations were obtained before and at intervals after Ep injections. The administration of Ep resulted in significant increases in maternal circulating Ep levels in sheep and monkeys. Despite the presence of high levels of maternal Ep, however, no increase in fetal plasma Ep levels was detected. The administration of Ep to the mother caused significant increases in reticulocyte production in the mother but not the fetus; injection of Ep directly to the fetus stimulated fetal erythropoiesis. These results demonstrate that Ep does not cross the placenta into the fetus even under conditions of chronically elevated maternal Ep levels, and suggest that red cell production in the fetus is regulated by Ep produced from sites within the fetus.
胎儿的红细胞生成受促红细胞生成素（Ep）控制。为确定母体Ep在此过程中的作用，我们使用了羊和猴胎儿的插管制剂，以评估给母体注射的Ep穿过胎盘屏障进入胎儿体内的能力。将Ep作为单次静脉剂量注入怀孕的羊（3600 IU/羊）或猴（800 - 2000 IU/动物），或以2000 IU的静脉剂量每12小时给羊注射一次，共注射4次。在注射Ep之前及之后的不同时间间隔采集母体和胎儿的血液样本，用于测定Ep和网织红细胞。给羊和猴注射Ep后，母体循环中的Ep水平显著升高。然而，尽管母体Ep水平很高，但未检测到胎儿血浆Ep水平升高。给母体注射Ep会使母体的网织红细胞生成显著增加，但胎儿的网织红细胞生成未增加；直接给胎儿注射Ep则刺激胎儿的红细胞生成。这些结果表明，即使在母体Ep水平长期升高的情况下，Ep也不会穿过胎盘进入胎儿体内，这表明胎儿的红细胞生成受胎儿体内产生的Ep调节。
