Endocrine Abstracts

Ligand-activated peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor, dimerises with retinoid X receptor(RXR) and acts as a transcription factor translating nutritional, pharmacological and metabolic stimuli into changes in gene expression. PPARgamma is thought to serve several roles in adipocyte differentiation, fatty acid and lipid metabolism, insulin sensitivity and ovarian steroidogenesis. PPARgamma has also been shown to increase gluco...

In vitro maturation (IVM) of oocytes obtained from medium sized antral follicles could avoid the need for superovulation for in vitro fertilisation. FSH is routinely added to culture media during IVM but the effects on oocyte health are unclear. The aim of this study was to assess the effect of FSH on 1) the metabolic activity of individual mouse cumulus-oocyte-complexes (COCs) matured in vitro,and 2) the genesis of chromosomal abnormalities. 274 mouse COC...

Polycystic ovary syndrome (PCOS) is characterised by reproductive, hyperandrogenic and dysmetabolic features (including insulin resistance). There remain major questions about the basis of the metabolic dysfunction in PCOS and about its genetic aetiology. Having genotyped samples from >460 PCOS cases and >1300 female controls, I recently successfully identified the first genome-sequence variant (the FTO gene) to be implicated in susceptibility to PCOS (Barber <i...

BMPs form part of the TGFβ superfamily, which are important regulators of proliferation and differentiation in many cell types. The intraovarian production of specific BMP members and their receptors in a stage-specific manner is crucial for normal follicle development to proceed. Regulation of BMP signalling pathways can occur by intracellular inhibition of the signal transducers (Smads), or by BMP antagonists that bind extracellular BMPs to prevent or alter ligand–...

Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility in women. Recent evidence suggests that early folliculogenesis is disordered and may contribute to development of anovulation in PCOS. Early follicle development in PCOS is characterised by increased expression of minichromosome maintenance protein-2 (MCM2), a marker of cell proliferation (Stubbs et al. 2007). Increased recruitment of growing preantral follicles has been reported in the p...

Recent studies have shown that serum concentrations of AMH (produced by granulosa cells of the human ovary) are positively related to the number of antral follicles and are negatively correlated with age. Like inhibin B (also a granulosa cell product) AMH is thought to be a useful clinical marker of follicle reserve. Serum AMH concentrations have been reported to be higher than normal in women with polycystic ovary syndrome (PCOS), which is characterised by an excess of antral...

Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility; anovulation in PCOS is characterised by arrest of antral follicle growth that may reflect the abnormal endocrine environment. However, it has recently been shown that preantral follicle development is also abnormal in PCO (Webber et al, Lancet 2003, 362 1017). In that study, the proportion of follicles in the primordial, resting, phase, was reduced, compared to normal ovaries, in tissue from bo...

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is one of the isoforms of the PPAR-family of nuclear hormone receptors. Ligand activated PPARs dimerise with retinoid X receptor and act as transcription factors translating nutritional, pharmacological and metabolic stimuli into changes in the expression of genes. PPARgamma is thought to serve several roles in adipocyte differentiation, fatty acid and lipid metabolism and insulin sensitivity. PPARgamma has also been...

Little is known about the place of insulin-like growth factors (IGFs) in preantral follicle development, although there is considerable evidence that IGFs are important in antral folliculogenesis. In the rat, isolated large preantral follicles developed better when cultured in vitro in the presence of IGF-I than without (Zhao et al 2001). In the same study, reverse transcriptase polymerase chain reaction identified mRNA for IGF-I and the type I receptor in the granulosa/theca ...

The role of the intra-ovarian insulin-like growth factor (IGF) system in preantral follicle development is unclear. Here we have examined the expression of mRNA for insulin-like growth factor-1 (IGF-1), IGF-2, Type 1-IGF receptor, Type 2-IGF receptor and insulin receptor (IR) in human pre-antral follicles at different stages. Ovarian cortex biopsies (5mm3) were obtained (with informed consent) during gynaecological surgery from six women (age 32.2 plus/minus SD 2.2,...