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Updated: Aug 15, 2026

A Modified Co-Culture System for Understanding Granulosa-Theca Cell Interactions in the Bovine Ovary
Published on: September 19, 2025
Leptin directly controls secretory activity of human ovarian granulosa cells: possible inter-relationship with the
A V Sirotkin1, M Mlyncek, J Kotwica
1Research Institute of Animal Production, Nitra, Slovakia. sirotkin@vuzv.sk
Aims:
The aim of our in vitro studies was to understand the role of leptin and the insulin-like growth factor I/insulin-like growth factor protein (IGF/IGFBP) system in controlling human ovarian function.
Methods:
We studied the action of leptin (0, 1, 10, or 100 ng/ml) and immunoneutralization of IGF-I using specific antiserum (0.1%) on the release of progesterone (P), estradiol (E), oxytocin (OT), IGF-I, IGFBP-3, and prostaglandins F (PGF) by these cells using radioimmunoassay/immunoradiometric assay.
Results:
It was found that leptin stimulated the secretion of OT, IGFBP-3, and PGF. It suppressed the secretion of E and IGF-I, but not P, into the medium. The addition of antiserum against IGF-I decreased IGF-I output, increased P, OT, IGFBP-3, and PGF secretion, and had no effect on E release. Immunoneutralization of IGF-I also prevented or reversed the effects of leptin on P, E, IGF-I, IGFBP-3, PGF, but not on OT.
Conclusions:
These observations (1) demonstrate that leptin directly controls the secretory activity of human ovarian cells, (2) confirm the involvement of IGF-I in the regulation of ovarian cells, and (3) suggest an inter-relationship between leptin and the IGF/IGFBP system in the control of these functions and the involvement of IGF/IGFBP system in mediating leptin action on the ovary.
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