Vascular Endothelial Growth Factor Inhibitory Isoform Is Regulated Prior to Ovulation

VEGF normally acts to stimulate vascular development (angiogenesis) and is necessary for ovulation of the dominant follicle. The inhibitory isoform blocks the actions of VEGF angiogenic isoforms; therefore, the objectives of the experiments were to identify the bovine inhibitory isoform, VEGF164b and to determine its expression prior to and after the LH surge. VEGF164b mRNA was upregulated prior to but did not change after the LH surge. Therefore, VEGF164b may be necessary for preparation of the dominant follicle prior to ovulation