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

Objective: To investigate the expression of vascular endothelial growth factor A (VEGF-A) and that its two receptors (VEGFR1, VEGFR2) in human preantral follicles. Design: Immunohistochemical, in situ hybridization, and reverse transcriptase polymerase chain reaction (RT-PCR) study of the expression of the VEGF-A system in human ovaries. Setting: Major 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.