Endocrine Abstracts

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,...

Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility in women, but its aetiology is poorly understood. There is evidence for a primary disorder of androgen secretion, which has its origins before puberty, but it is not clear how this may cause the characteristic ovarian abnormalities. We have developed an ovine model for PCOS to explore possible differences between the small preantral follicles of androgenised female lambs with those of normal ova...

Polycystic ovary syndrome (PCOS) is a multifactorial, complex endocrine disorder affecting a significant proportion of the global population. Hyperandrogenism is a key feature of PCOS patients. Aberrant secretion and/or action of gonadotropins have been implicated in PCOS, but, to date, we have only limited knowledge of how these factors may interact in the aetiology of PCOS. We hypothesised that excess androgens may cause aberrant gonadotropin activity and therefore sought to...

Defects in any of the four functional domains of the androgen receptor (AR) (resulting from loss-of-function or gain-of-function mutations), may affect androgen action. Specific AR splice variants have been reported in women with PCOS (Wang et al, PNAS 2015 112 4743). In this study we sought to identify AR splice variants in granulosa-lutein (GL) cells of women with and without PCOS and to assess their functional significance. GL cells were ...

Central obesity and increased visceral adipose tissue (VAT) are key factors contributing to metabolic dysfunction in PCOS. We therefore hypothesized that there would be alterations in the morphology and function of adipocytes from visceral fat depots. The female offspring of pregnant sheep treated biweekly with either 100 mg of testosterone propionate (TP) or vehicle control (C) from day 62–102 of gestation develop a clinically realistic PCOS-like condition. They develop ...

Women with Polycystic Ovary Syndrome (PCOS) are at increased risk of developing insulin resistance, obesity and dyslipidemia, however obesity per se does not explain the higher incidence of insulin resistance in PCOS women when compared to the general population. Altered adipose tissue morphology and function may be a central factor contributing to metabolic disturbances in PCOS. Using a clinically realistic ovine model of PCOS we reported hyperinsulinaemia and early ...

Polycystic ovary syndrome is the commonest cause of anovulation. The mechanism of the aberrant follicle development that is associated with anovulation remains unclear. However, data from human studies and from animal models of PCOS suggest that excess androgen production, the biochemical hallmark of PCOS, has a role in disordered follicle development. The aim of this study was to examine the direct effect of androgens on isolated mouse preantral follicles in culture. Multilay...