Ovarian vascular endothelial growth factor and vascular endothelial growth factor receptor patterns in reproductive aging

ObjectiveTo investigate how levels of vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) change during corpus luteum formation in reproductive aging.DesignAdult and reproductive aging female rats were given pregnant mare serum gonadotropin (PMSG) and the ovaries and sera were collected at 0, 3, 5, and 7 days after human chorionic gonadotropin (hCG) injection.SettingLaboratory study.Patient(s)Animal model.Intervention(s)Induction of corpus luteum formation with PMSG-hCG.Main Outcome Measure(s)Western blot analysis for ovarian VEGF, VEGFR-1, VEGFR-2, and hypoxia-induced factor 1 (HIF1-alpha). Enzyme-linked immunosorbent assay (ELISA) measurement of serum VEGF levels.Result(s)For VEGF and VEGFR-1, there was no difference between the adult and the reproductive aging ovaries. For total VEGFR-2 levels, the adult ovaries had a decline during corpus luteum formation. In contrast, the levels of the two forms of phosphorylated VEGFR-2 declined in aging ovaries. There was a decline in HIF1-alpha during corpora lutea formation in the reproductive aging rats.Conclusion(s)The reproductive aging corpora lutea have a temporal decline in phosphorylated VEGFR-2 levels but not in the total VEGFR-2 levels. The data suggest that the VEGFR response mechanism is different in the aging ovary.