Shimizu Takashi, Jiang Jin-Yi, Sasada Hiroshi, Sato Eimei
Laboratory of Animal Reproduction, Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai 981-8555, Japan.
Biol Reprod. 2002 Dec;67(6):1846-52. doi: 10.1095/biolreprod.102.006734.
The interaction between angiogenic factors and related receptors is closely associated with follicular angiogenesis. The present study was performed to determine the relationships between the capillary network and mRNA expression of several angiogenic factors and related receptors during porcine follicular development. Ovaries in gilts were collected 72 h after eCG (1250 IU) treatment for histological observation. Granulosa cells and thecal tissues in small (diameter, <4 mm), medium (diameter, 4-5 mm), or large (diameter, >5 mm) individual follicles were collected for detection of mRNA expression of vascular endothelial growth factor (VEGF) 120, VEGF 164, basic fibroblast growth factor (bFGF), and epidermal growth factor (EGF) in granulosa cells and fms-like tyrosine kinase (Flt-1), fetal liver kinase (Flk-1) or the murine homologue of kinase domain region (KDR), bFGF receptor (bFGF-R), and EGF receptor (EGF-R) in thecal tissue by semiquantitative reverse transcription-polymerase chain reaction. The eCG treatment resulted in the emergence of healthy preovulatory follicles (diameter, >6.0 mm) that possessed more capillaries in the thecal cell layer and a significant increase in the percentage of atretic follicles of 1.0-2.9 mm in diameter. The number of capillaries in the thecal cell layer increased significantly in healthy follicles larger than 3 mm in diameter in the eCG group compared with those in controls. The expression of VEGF 120, VEGF 164, and bFGF mRNAs increased in granulosa cells of medium and large follicles from ovaries of prepubertal gilts after eCG treatment. The Flt-1, Flk-1/KDR, and bFGF-R mRNA expression increased in theca cells of medium and large follicles after eCG treatment. The expression of EGF mRNA increased in granulosa cells of small, medium, and large follicles from ovaries after eCG treatment, but the mRNA expression of EGF-R in thecal tissue did not change. These data indicate that preovulatory follicles possessed a larger capillary network and expressed more mRNAs of angiogenic factors in granulosa cells and related receptors in thecal tissue. We concluded that VEGF 120, VEGF 164, bFGF, and EGF may be greatly involved in the angiogenic process of follicular development in prepubertal gilts with eCG treatment.
血管生成因子与相关受体之间的相互作用与卵泡血管生成密切相关。本研究旨在确定猪卵泡发育过程中毛细血管网络与几种血管生成因子及相关受体mRNA表达之间的关系。在给予孕马血清促性腺激素（eCG，1250 IU）处理72小时后收集后备母猪的卵巢进行组织学观察。收集直径小于4mm的小卵泡、直径4 - 5mm的中卵泡或直径大于5mm的大卵泡中的颗粒细胞和卵泡膜组织，通过半定量逆转录-聚合酶链反应检测颗粒细胞中血管内皮生长因子（VEGF）120、VEGF 164、碱性成纤维细胞生长因子（bFGF）和表皮生长因子（EGF）以及卵泡膜组织中fms样酪氨酸激酶（Flt-1）、胎儿肝激酶（Flk-1）或激酶结构域区域的小鼠同源物（KDR）、bFGF受体（bFGF-R）和EGF受体（EGF-R）的mRNA表达。eCG处理导致出现健康的排卵前卵泡（直径大于6.0mm），其卵泡膜细胞层有更多毛细血管，且直径为1.0 - 2.9mm的闭锁卵泡百分比显著增加。与对照组相比，eCG组中直径大于3mm的健康卵泡的卵泡膜细胞层毛细血管数量显著增加。eCG处理后，初情期前后备母猪卵巢中、大卵泡颗粒细胞中VEGF 120、VEGF 164和bFGF mRNA表达增加。eCG处理后，中、大卵泡卵泡膜细胞中Flt-1、Flk-1/KDR和bFGF-R mRNA表达增加。eCG处理后，卵巢中小、中、大卵泡颗粒细胞中EGF mRNA表达增加，但卵泡膜组织中EGF-R的mRNA表达未改变。这些数据表明，排卵前卵泡拥有更大的毛细血管网络，颗粒细胞中血管生成因子的mRNA表达更多，卵泡膜组织中相关受体表达更多。我们得出结论，VEGF 120、VEGF 164、bFGF和EGF可能在eCG处理的初情期前后备母猪卵泡发育的血管生成过程中发挥重要作用。
