The bidirectional communication between oocytes and granulosa cells are mediated by several factors via a local feedback loop(s). The current model was carried out to study the spatial mutual interaction of porcine denuded oocytes and granulosa cells either in direct contact (juxtacrine) or paracrine co-culture using transwell system. Transwell 0.4 μm polyester membrane inserts were used to per...

Only a minute fraction of ovarian follicles present in a foetal ovary will complete the path to ovulation. The majority of the follicles will instead undergo atresia, a hormonally controlled apoptotic process. Apoptosis occurs throughout follicle development, with an extensive reduction in the number of follicles present at birth. Interestingly, this drastic reduction is not present among preov...

Patch clamp experiments were conducted to study the effects of basal lamina (basement membrane) of chicken ovarian follicle on membrane Ca(2+) currents in differentiated chicken granulosa cells in a homologous system. The whole cell patch clamp technique was used to simultaneously monitor membrane capacitance (an indirect measure of total cell surface area) and currents flowing through voltage-...

Angiotensin II (AngII) is best known for its role in blood pressure regulation, but it also has documented actions in the reproductive system. There are two AngII receptors, type 1 (AGTR1) and type 2 (AGTR2). AGTR2 mediates the noncardiovascular effects of AngII and is expressed in the granulosa cell layer in rodents and is associated with follicle atresia. In contrast, expression of AGTR2 is r...

A-kinase anchoring proteins (AKAPs) function to target protein kinase A (PKA) to specific locations within the cell. AKAPs are functionally identified by their ability to bind the type II regulatory subunits (RII) of PKA in an in vitro overlay assay. We previously showed that follicle-stimulating hormone (FSH) induces the expression of an 80-kDa AKAP (AKAP 80) in ovarian granulosa cells as they...

Paracrine cell signaling is believed to be important for ovarian follicle development, and a role for some members of the fibroblast growth factor (FGF) family has been suggested. In the present study, we tested the hypothesis that FGF-8 and its cognate receptors (FGFR3c and FGFR4) are expressed in bovine antral follicles. RT-PCR was used to analyze bovine Fgf8, Fgfr3c and Fgfr4 mRNA levels in ...

The Fas antigen (Fas) is a cell surface receptor that may be involved in the initiation and progression of follicle cell apoptosis during atresia. Fas initiates apoptosis in sensitive cells after binding Fas ligand (FasL). Other experiments have shown that expression of Fas mRNA and responsiveness to Fas-mediated apoptosis vary in bovine granulosa and theca cells during follicle development. In...

the association of secreted frizzled related protein type 4 (sfrp4) as an antagonist of wnt mole-cules in apoptotic events has been reported previously. moreover, its increased expression has been reported in the ovary of women with polycystic ovary (pco). we have demonstrated in-creased sfrp4 in pco-induced rat ovary related to an increased number of apoptotic follicles showing nuclear ?cateni...

Ovarian follicular fluid peptide (OFFP) purified from sheep ovaries enhances apoptotic changes in ovarian granulosa cells of mice. To get an insight into the cell subpopulations responding to OFFP, the heterogeneity of granulosa cells was resolved. Subpopulations of granulosa cells were obtained from ovaries of immature mice treated with PMSG alone and autopsied 48 hr (control) and 72 hr after ...

Granulosa cell death is an early feature of atresia; however, there are many apparent contradictions in the literature concerning the mode of granulosa cell death. We have therefore examined this process in bovine healthy and atretic antral follicles, using a variety of established techniques. Light and electron microscopic observations indicated the presence of pyknotic or shrunken nuclei in b...