Borowicz Pawel P, Arnold Daniel R, Johnson Mary Lynn, Grazul-Bilska Anna T, Redmer Dale A, Reynolds Lawrence P
Center for Nutrition and Pregnancy, Department of Animal and Range Sciences, North Dakota State University, Fargo, North Dakota 58105-5727, USA.
Biol Reprod. 2007 Feb;76(2):259-67. doi: 10.1095/biolreprod.106.054684. Epub 2006 Oct 18.
Morphometric methodologies were developed and applied to investigate the patterns of vascular development in maternal (caruncular; CAR) and fetal (cotyledonary; COT) sheep placentas throughout the last two thirds of gestation. We also examined the expression levels of the major angiogenic factors and their receptors in CAR and COT sheep placentas. Although the vascularity of the CAR tissues increased continuously from Day 50 through Day 140 of pregnancy, those of the COT tissues increased at about twice the instantaneous rate (i.e., the proportionate increase/day) of the CAR. For CAR, vascularity increased 2-fold from Day 50 through Day 140 via relatively small increases in capillary number and 2- to 3-fold increases in capillary diameter. For COT, the increased vascularity resulted from a 12-fold increase in capillary number associated with a concomitant 2-fold decrease in capillary diameter. This large increase in fetal placental capillary number, which was due to increased branching, resulted in 6-fold increases in total capillary cross-sectional area and total capillary surface, per unit of COT tissue. Different patterns of expression of the mRNAs for angiogenic factors and their receptors were observed for CAR and COT. The dilation-like angiogenesis of CAR was correlated with the expression of vascular endothelial growth factor receptor-1 (FLT1), angiopoietin-2 (ANGPT2), and soluble guanylate cyclase (GUCY1B3) mRNAs. The branching-like angiogenesis of COT was correlated with the expression of vascular endothelial growth factor (VEGF), FLT1, angiopoietin-1 (ANGPT1), ANGPT2, and FGF2 mRNAs. Monitoring the expression of angiogenic factors and correlating the levels with quantitative measures of vascularity enable one to model angiogenesis in a spatiotemporal fashion.
已开发并应用形态测量方法来研究妊娠最后三分之二期间母羊（肉阜；CAR）和胎儿（绒毛叶；COT）胎盘的血管发育模式。我们还检测了CAR和COT绵羊胎盘主要血管生成因子及其受体的表达水平。尽管CAR组织的血管密度在妊娠第50天至第140天持续增加，但COT组织的血管密度增加速度约为CAR的两倍（即每天的比例增加）。对于CAR，从第50天到第140天，血管密度增加了2倍，这是由于毛细血管数量相对小幅增加以及毛细血管直径增加了2至3倍。对于COT，血管密度增加是由于毛细血管数量增加了12倍，同时毛细血管直径减少了2倍。胎儿胎盘毛细血管数量的大幅增加是由于分支增加，导致每单位COT组织的总毛细血管横截面积和总毛细血管表面积增加了6倍。观察到CAR和COT的血管生成因子及其受体mRNA的表达模式不同。CAR的扩张样血管生成与血管内皮生长因子受体-1（FLT1）、血管生成素-2（ANGPT2）和可溶性鸟苷酸环化酶（GUCY1B3）mRNA的表达相关。COT的分支样血管生成与血管内皮生长因子（VEGF）、FLT1、血管生成素-1（ANGPT1）、ANGPT2和FGF2 mRNA的表达相关。监测血管生成因子的表达并将其水平与血管密度的定量测量相关联，能够以时空方式模拟血管生成。
