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

Objective: To investigate how levels of vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) change during corpus luteum formation in reproductive aging. Design: Adult 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. Setting: Laboratory 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 I (HIFI-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 HIFI-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.