Objective: To investigate the immunocytochemical expression and presence of mRNA transcripts of oncostatin M (OSM) and its exclusive receptor (OSM-Rbeta) in ovaries from human adults and fetuses.
Design: Immunocytochemical and reverse transcription polymerase chain reaction (RT-PCR) study.
Setting: Major tertiary care and referral academic centers.
Patient(s): Ten women and girls undergoing laparoscopic ovarian biopsy and 30 women undergoing second-trimester and third-trimester pregnancy terminations.
Intervention(s): None.
Main outcome measure(s): Microscopic morphometric analysis, immunocytochemistry for OSM and OSM-Rbeta, and RT-PCR analyses.
Result(s): There was strong to moderate immunocytochemical staining for OSM in both oocytes and granulosa cells of follicles from primordial stages onwards in ovaries from both fetuses and adults/adolescents. OSM-Rbeta was detected mainly in the oocytes. Transcripts of OSM and OSM-Rbeta RNA were detected by RT-PCR analyses.
Conclusion(s): The expression of OSM and its receptor in ovarian tissue from fetuses and women suggests a possible role of OSM in growth initiation of human primordial follicles.