Vascular endothelial growth factor A and its two receptors in human preantral follicles from fetuses, girls, and women

ObjectiveTo investigate the expression of vascular endothelial growth factor A (VEGF-A) and that its two receptors (VEGFR1, VEGFR2) in human preantral follicles.DesignImmunohistochemical, in situ hybridization, and reverse transcriptase polymerase chain reaction (RT-PCR) study of the expression of the VEGF-A system in human ovaries.SettingMajor tertiary-care academic center.Patient(s)Twenty-two patients who underwent pregnancy terminations at 21–35 gestational weeks and 29 girls/women aged 5–39 years who underwent ovarian laparoscopies.Intervention(s)None.Main Outcome Measure(s)Laboratory analysis of human ovarian specimens.Result(s)Immunhistochemistry and in situ hybridization revealed the expression of the proteins and mRNA transcripts for VEGFR1 and VEGFR2 in oocytes, granulosa cells, and stroma cells from fetuses and girls/women. The protein for VEGF-A was detected immunohistochemically in oocytes, granulosa cells, and stroma cells from fetuses and girls. VEGF-A and VEGFR1 proteins were expressed more strongly than VEGFR2. VEGF-A121, VEGF-A165, and VEGF-A189 isoforms were identified by RT-PCR in the ovarian samples from fetuses and women.Conclusion(s)The presence of the VEGF-A receptors, particularly in the granulosa cells, suggests that VEGF-A might be involved in proliferation initiation of primordial follicles or play an as yet unknown role in human preantral follicles.