Binding sites for IGF-I, insulin, and GH were localized by in situ binding of (125)I-labelled hormones to the different compartments of the sow ovary. Binding sites for IGF-I were detected in oocytes, granulosa and thecal cells of healthy and atretic follicles as well as in the antrum and the stroma. Competition of (125)I-labelled IGF-I with IGF-I, insulin and an analogue of IGF-I (Long R(3)IGF...

the cyclical changes in the gonadotropins stimulate ovarian follicular development either to the ovulatory stage or to undergo atresia. one such intrafollicular factor may be inter-cellular communication via gap junctions. we have examined the effects of two agents (retinoids and alkanols), known to disrupt or uncouple gap junction, on fsh-stimulated lh receptor induction and progestrone synthe...

Functional subpopulations of granulosa cells exist in bovine follicles. This study was designed to compare the in vitro steroid production by cultured bovine antral and mural granulosa cells in response to various amounts of FSH. Antral and mural granulosa cells (600,000 viable cells/well) harvested from ovaries of PMSG-treated prepuberal calves were cultured in serum-free conditions for 4 d in...

Follicular development is characterized by intensive proliferation and differentiation of granulosa cells. It was reported that during follicular growth granulosa cells arise from the population of stem cells. One of the main evidences for stem characteristics of the cell is the ability to express telomerase--an enzyme complex responsible for integrity and stability of chromosome ends (telomere...

Hyperandrogenism is known to perturb ovarian physiology resulting in anovulatory conditions. In the ovary, androgens produced by theca-interstitial cells are converted to estrogens in granulosa cells under the influence of FSH and LH. In some of the target organs, including the ovary, androgens are also converted into their 5alpha reduced metabolites. In the present study, we examined the molec...

The timing of cellular exit from the cell cycle during differentiation is specific for each cell type or lineage. Granulosa cells in the ovary establish quiescence within several hours after the ovulation-inducing luteinizing hormone surge, whereas they undergo differentiation into corpora lutea. The expression of Cdk inhibitors p21(Cip1/Waf1) and p27(Kip1) is up-regulated during this process, ...

We investigated aromatization and the mechanism of action of epidermal growth factor (EGF) and transforming growth factor alpha (TGFalpha) on oestradiol biosynthesis in freshly prepared granulosa cells from polycystic ovaries. Freshly prepared granulosa cells from polycystic ovaries incubated for only 3 h under basal conditions secreted significantly (P< 0.001) greater amounts of oestradiol-17b...

Folliculogenesis is a progressive and highly regulated process, which is essential to provide ova for later reproductive life, requires the bidirectional communication between the oocyte and granulosa cells. This physical connection-mediated communication conveys not only the signals from the oocyte to granulosa cells that regulate their proliferation but also metabolites from the granulosa cel...

The activity of granulosa cells derived from different sized follicles surrounding oocytes of apparently comparable maturity was evaluated in hyperstimulated ovaries. Granulosa cells were obtained from women undergoing gamete intra-Fallopian transfer procedures who had been treated with gonadotrophin-releasing hormone analogue and gonadotrophins. Only follicles with oocytes of apparently compar...

Coordinated interactions between ovarian granulosa and theca cells are required for female endocrine function and fertility. To elucidate these interactions the regulation of the granulosa and theca cell transcriptomes during bovine antral follicle development were investigated. Granulosa cells and theca cells were isolated from small (<5 mm), medium (5-10 mm), and large (>10 mm) antral bovine ...