Grazul-Bilska A T, Navanukraw C, Johnson M L, Vonnahme K A, Ford S P, Reynolds L P, Redmer D A
Department of Animal and Range Sciences, North Dakota State University, Fargo 58105, USA.
J Anim Sci. 2007 Aug;85(8):1914-22. doi: 10.2527/jas.2007-0044. Epub 2007 Apr 27.
To determine the relationships among vascularity, expression of angiogenic factors, and selected intrafollicular factors in dominant and nondominant follicles of the first follicular wave, ovaries were obtained on d 3 of the estrous cycle from mature cross-bred beef heifers (n = 8) after a synchronized estrus. Follicular fluid (FF) was collected from all follicles > or = 3 mm for determination of estradiol-17beta (E), progesterone (P4), vascular endothelial growth factor (VEGF), and IGFBP concentrations. The ovaries were then perfusion-fixed and used for histochemical detection of lectin BS-1 (a marker of endothelial cells and thus vascularization) binding, and immunolocalization of VEGF, endothelial nitric oxide synthase (eNOS), and proliferating cell nuclear antigen, followed by image analysis of selected follicles. Follicles were classified, based on E and P4 concentrations in FF, as dominant, estrogen-active (EA; E:P4 > or = 1) or nondominant, estrogen-inactive (EI; E:P4 <1). Concentrations of E and VEGF in FF, the area of positive staining for lectin BS-1, VEGF, and eNOS, and the labeling index (an index of the percentage of cells proliferating) in granulosa and theca layers were greater (P < 0.05) in the EA than in the EI follicles, but concentrations of P4 and IGFBP in FF were less (P < 0.05) in EA than in EI follicles. In addition, vascularity was positively correlated (P < 0.05) with VEGF and eNOS protein expression, and tended (P < 0.1) to be positively correlated with the E:P4 ratio in FF but tended (P < 0.1) to be negatively correlated with IGFBP and P4 concentrations in FF. These data highlight the importance of vascularity, angiogenic factors, and IGFBP in the health of the dominant follicle in heifers, and indicate that the FF concentrations of E, VEGF, IGFBP, and P4, and the E:P4 ratio can be used as markers of dominant follicles.
为了确定发情周期第一个卵泡波中优势卵泡和非优势卵泡的血管生成、血管生成因子表达以及卵泡内特定因子之间的关系，在同步发情后，于发情周期第3天从成熟的杂交肉用小母牛（n = 8）获取卵巢。收集所有直径≥3 mm卵泡的卵泡液（FF），用于测定雌二醇-17β（E）、孕酮（P4）、血管内皮生长因子（VEGF）和胰岛素样生长因子结合蛋白（IGFBP）浓度。然后对卵巢进行灌注固定，用于凝集素BS-1（内皮细胞标记物，因此也是血管生成标记物）结合的组织化学检测，以及VEGF、内皮型一氧化氮合酶（eNOS）和增殖细胞核抗原的免疫定位，随后对选定卵泡进行图像分析。根据卵泡液中E和P4浓度，卵泡分为优势卵泡、雌激素活性（EA；E:P4≥1）卵泡或非优势卵泡、雌激素非活性（EI；E:P4＜1）卵泡。EA卵泡的卵泡液中E和VEGF浓度、凝集素BS-1、VEGF和eNOS阳性染色面积以及颗粒层和卵泡膜层的标记指数（细胞增殖百分比指数）均高于EI卵泡（P＜0.05），但EA卵泡的卵泡液中P4和IGFBP浓度低于EI卵泡（P＜0.05）。此外，血管生成与VEGF和eNOS蛋白表达呈正相关（P＜0.05），与卵泡液中E:P4比值呈正相关趋势（P＜0.1），但与卵泡液中IGFBP和P4浓度呈负相关趋势（P＜0.1）。这些数据突出了血管生成、血管生成因子和IGFBP在小母牛优势卵泡健康中的重要性，并表明卵泡液中E、VEGF、IGFBP和P4浓度以及E:P4比值可作为优势卵泡的标志物。
