Does vascular endothelial growth factor (VEGF) play a role in cyclic changes of the cervix?

Objective: Around the time of ovulation the cervix opens and the cervical m ucus liquefies. Vascular endothelial growth factor (VEGF), a potent inducto r of vascular permeability, may play a role in these changes. We examined V EGF in cervical tissue specimens and cervical mucus at different stages of the menstrual cycle. Methods: Samples of tissue and mucus from the uterine cervix were obtained from specimens from 20 premenopausal patients undergoing hysterectomy. Eigh t uteri were removed during the follicular phase (day 1 - 8), five in the p eriovulatory phase (day 12 - 16), and seven in the secretory phase (day 17 - 28). Paraffin-embedded slides were stained with a VEGF antibody covering the splicing variants 165,189 and 121. Cervical mucus was examined for VEGF 165 with an enzyme-linked immunoassay. Data were analyzed with the Wilcoxo n two-sample test. Results: Uteri in the early proliferative phase showed distinct VEGF staini ng of the basal epithelium of the cervix. During the late follicular and pe riovulatory phases, staining in the apical epithelium and cervical stroma i ncreased and the VEGF concentration in the cervical mucus was highest (97 p g/mg total protein). After ovulation VEGF in the epithelium fell sharply, t o then reappear in the mid and late secretory phase. Conclusion: VEGF increases in the cervical stroma around the time of ovulat ion and may play a role in the liquefaction of the cervical mucus and tissu e edema. These changes are likely involved with the opening of the cervix a t near the time of ovulation.