Boonyaprakob U, Gadsby J E, Hedgpeth V, Routh P, Almond G W
Department of Farm Animal Health and Resource Management, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA.
Reproduction. 2003 Sep;126(3):393-405. doi: 10.1530/rep.0.1260393.
Expression and localization of mRNAs for vascular endothelial growth factor (VEGF), VEGF receptor 1 (Flt) and VEGF receptor 2 (KDR) (VEGFR-1 and VEGFR-2, respectively) were investigated in pig corpora lutea. Northern blot analysis of total RNA indicated hybridization of pig VEGF, VEGFR-1 and VEGFR-2 cDNA probes to mRNA transcripts of approximately 3.9, 7.0 and 5.0 kb, respectively. The expression of mRNAs for VEGF and its receptors during the luteal phase (days 4, 7, 10, 13 and 15 after the onset of oestrus) were assessed by northern blot analysis, and hybridization signals were normalized to expression of pig 18S rRNA. Relative hybridization signals of expression of VEGF mRNA appeared to be constant; however, expression of VEGFR-1 mRNA was low on day 4, increased on day 7, and was higher on days 10, 13 and 15 (P<0.05, compared with day 4). In contrast, no changes in expression of mRNA for VEGFR-2 were evident on days 4-13, but a decrease was detected (P<0.05) at day 15. In situ hybridization revealed that VEGF mRNA was localized predominantly in large luteal cells, whereas both VEGFR-1 and VEGFR-2 were localized to small cells. These data indicate that the VEGF system may be involved in the regulation of luteal vasculature throughout the lifespan of the corpus luteum. Although the expression of VEGF mRNA was unchanged during the luteal phase, variations in the expression of VEGFR-1 and VEGFR-2 mRNAs indicate that differential regulation of expression of the VEGF receptors may play a role in the control of VEGF-mediated vascular growth at different phases of development and maturation of the pig corpus luteum.
研究了猪黄体中血管内皮生长因子（VEGF）、VEGF受体1（Flt）和VEGF受体2（KDR）（分别为VEGFR-1和VEGFR-2）mRNA的表达及定位情况。对总RNA进行的Northern印迹分析表明，猪VEGF、VEGFR-1和VEGFR-2 cDNA探针分别与约3.9、7.0和5.0 kb的mRNA转录本杂交。通过Northern印迹分析评估了黄体期（发情开始后第4、7、10、13和15天）VEGF及其受体mRNA的表达情况，并将杂交信号标准化为猪18S rRNA的表达。VEGF mRNA表达的相对杂交信号似乎恒定；然而，VEGFR-1 mRNA在第4天表达较低，第7天增加，在第10、13和15天更高（与第4天相比，P<0.05）。相比之下，VEGFR-2 mRNA在第4至13天表达无明显变化，但在第15天检测到下降（P<0.05）。原位杂交显示，VEGF mRNA主要定位于大黄体细胞，而VEGFR-1和VEGFR-2均定位于小细胞。这些数据表明，VEGF系统可能在黄体的整个生命周期中参与黄体血管系统的调节。虽然VEGF mRNA在黄体期表达未变，但VEGFR-1和VEGFR-2 mRNA表达的变化表明，VEGF受体表达的差异调节可能在猪黄体发育和成熟的不同阶段控制VEGF介导的血管生长中发挥作用。
