Endocrine Abstracts

Metformin is commonly used to treat insulin resistance in women with polycystic ovary syndrome (PCOS) and also has direct effects on the ovary. The mechanism of this action is unknown, but could be via insulin-independent pathways, namely AMP activated protein kinase (AMPK). AMPK is an energy sensor, activated when ATP levels are depleted causing an inhibition of anabolic and an activation of catabolic pathways. We hypothesised that in the ovary, metformin acts via</...

AMH, the fetal testicular sexual differentiative factor, is now implicated in adult ovarian function. Antral follicle immunohistochemistry demonstrated AMH protein and message, the staining peaking around 4 mm. Interestingly, AMH-knockout mice have increased FSH sensitivity. Our aim was to measure AMH in follicular fluid and cell-conditioned medium and AMHRII in normal ovaries from women undergoing TAH/BSO.Follicles were dissected intact, follicular flui...

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. Although the cause of the anovulation is unknown there are a number of endocrine candidates; hyperinsulinaemia, raised steroid production and increased levels of the sexual differentiative factor anti-Müllerian hormone (AMH). The latter is increasingly thought to be an inhibitor of folliculogenesis. Hyperinsulinaemia in PCOS is now widely treated with metformin and we have shown that thi...

AMH causes regression of Müllerian ducts during male fetal development. Recently, AMH was detected in the adult ovary, principally in granulosa cells (GCs). Studies have demonstrated a 1.5–5 fold increase in serum AMH in women with PCOS compared to normal ovulatory women. The AMH rise was assumed to be secondary to increased numbers of follicles. Interestingly, the insulin sensitiser metformin, which is in widespread use in PCOS, caused a significant reduction in ser...

There is evidence from animal studies that 1,25-dihyroxyvitamin D3 (1,25(OH)2D3) is essential for normal reproductive function. Vitamin deficient rats have reduced fertility and VDR null mutant mice demonstrate impaired folliculogenesis. One small uncontrolled study in humans has demonstrated that vitamin D replacement improves menstrual frequency and acne in women with polycystic ovary syndrome (PCOS). We have previously demonstrated that 1,25(OH)2D3 inh...