Endocrine Abstracts

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...

Phytoestrogens bind weakly to oestrogen receptors and can initiate oestrogen-dependent transcription. They are promoted as natural alternatives to HRT and yet epidemiological evidence suggests that they may protect against breast and prostate cancer. Studies in cell-free preparations have shown that phytoestrogens can inhibit the activity of aromatase and that the inhibition is, at least partly, competitive with androgen substrates. The question as to whether chronic exposure ...

Studies on breast cancer cell lines, placental microsomes and purified recombinant enzymes have shown that various phytoestrogens can inhibit both aromatase and 17beta-hydroxysteroid dehydrogenase (HSD) enzymes. This has led to the suggestion that certain phytoestrogens may exert their endocrine disrupting functions by enzyme inhibition rather than their ability to bind weakly to oestrogen receptors. Previous studies have shown that genistein, the active ingredient of soy, ind...

Numerous investigations have shown that FSH can induce aromatase in granulosa cells obtained from natural ovarian cycles. In contrast granulosa luteal (GL) cells obtained from patients undergoing procedures for IVF are generally insensitive to FSH-induction of aromatase. A few studies, however, have reported that GL cells can be sensitized to this gonadotrophin. In these experiments we compared the conversion of various steroid substrates - namely pregnenolone and androstenedi...

Recent evidence indicates that the increase in follicle numbers seen in PCOS occurs early in folliculogenesis, and that androgens are implicated in this. In primates and sheep, androgen excess in-utero results in ovarian changes similar to those in PCOS. We have recently shown using a novel in ovo model, that testosterone added to implanted human tissue increased primary follicles compared to untreated tissue (Qureshi et al. 2005). This is similar to the p...

BackgroundPCOS is the commonest endocrinopathy in women. PCO are typified by increased ovarian follicles. The aetiology is unknown, but may be due either to enhanced follicular growth, reduced atresia, or both. Hyperandrogenism is almost universal either clinically or biochemically and in primates and sheep androgen excess in-utero produces ovaries phenotypically identical to those in PCOS. There have been no analyses of the effects of androgens on early...

BackgroundCurrent techniques to study the early stages of follicular development (i)in vitro(/i) are handicapped by the spontaneous wholesale transition of primordial to primary follicles and by primary follicle arrest. We have circumvented this problem by culturing fragments of ovarian cortical tissue on the chorioallantoic membrane (CAM) of chick embryos and shown it to be successful for the (i)in ovo(/i) culture of cortical slices from a variety of sp...

Current techniques to study (i)in vitro(/i) the early stages of follicular development are handicapped by the spontaneous wholesale transition of primordial to primary follicles. Implantation of ovarian tissue into SCID mice is possible but expensive. We have, therefore, adapted a model first described in 1958. Fragments of ovarian cortex are implanted on the chorioallantoic membrane (CAM) of 5-6 day old fertilised chick eggs. The membrane is rich in blood vessels and results ...

OBJECTIVE Recent studies have shown the benefits of insulin sensitising agents such as Metformin in the treatment of infertility and hirsuitism in PCOS. However not all women with PCOS are insulin resistant. Within a clinic population of women referred for treatment of hirsuitism, we examined the utility of fasting insulin/glucose measurement in identifying which women were insulin resistant.DESIGN We evaluated an outpatient clinic group of 25 PCOS pati...

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...