Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA.
Pediatr Res. 2011 Jun;69(6):485-90. doi: 10.1203/PDR.0b013e3182181e01.
Chronic fetal anemia results in significant cardiac remodeling. The capacity to reverse these effects is unknown. We examined the effects of transfusion on cardiomyocyte adaptations after chronic anemia in fetal sheep subjected to daily hemorrhage beginning at 109-d GA (term ∼145 d). After 10 d of anemia, one group was killed for comparison with age-matched controls. A separate group of anemic fetuses was transfused with red blood cells at 119-d GA for comparison with controls at 129-d GA. Anemia significantly increased the heart-to-body weight ratio, an effect partially ameliorated after transfusion. Cardiomyocyte dimensions were similar among all groups, suggesting an absence of hypertrophy. The percentages of mono- and binucleated cardiomyocytes were similar between groups at 119-d GA, although the percentage of binucleated cells was significantly less in transfused fetuses compared with controls at 129-d GA. Protein levels of mitogen-activated protein kinases and protein kinase B were similar between controls and their respective intervention groups, except for a significant increase in phosphorylated c-Jun N-terminal kinase 1/2 in transfused fetuses. Thus, cardiomyocyte proliferation but not hypertrophy contributes to cardiac enlargement during fetal anemia. Transfusion results in slowing but not cessation of cardiac growth after anemia.
慢性胎儿贫血会导致显著的心脏重构。目前尚不清楚是否能够逆转这些影响。我们研究了在 109 天龄 GA（足月约 145 天）的胎儿羊每日出血导致慢性贫血后，输血对心肌细胞适应性的影响。在贫血 10 天后，一组被处死，与同龄对照组进行比较。另一组贫血胎儿在 119 天龄 GA 时输血，并与 129 天龄 GA 的对照组进行比较。贫血显著增加了心脏与体重的比值，输血后部分改善了这种情况。心肌细胞尺寸在所有组之间相似，表明没有肥大。在 119 天龄 GA 时，各组之间单核和双核心肌细胞的百分比相似，但在 129 天龄 GA 时，输血胎儿的双核细胞百分比明显低于对照组。除了转铁蛋白胎儿中磷酸化 c-Jun N-末端激酶 1/2 显著增加外，对照组及其各自干预组之间的有丝分裂原激活蛋白激酶和蛋白激酶 B 的蛋白水平相似。因此，心肌细胞增殖而不是肥大导致胎儿贫血时心脏扩大。输血导致贫血后心脏生长减缓但未停止。
