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</...

Extracts of black cohosh (BCE) are frequently used as an alternative to conventional HRT to treat menopausal symptoms, particularly in Germany and the United States. In fact, BCE is the 14th most popular herbal product in the US and in 2003 sales were at least $15.7 million. Evidence for an increased incidence of breast cancer in long-term users of HRT has reduced its use and may increase the use of alternative treatments. These still require rigorous scientific investigation,...

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...

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...

3beta-hydroxysteroid dehydrogenase (3beta-HSD) expression is essential for the synthesis of all classes of steroid hormones, converting delta5beta-hydroxysteroids into hormonally active delta4-3-ketosteroids in NAD+-dependent reactions. Numerous 3beta-HSD isoforms have been described in mouse, rat, human and other mammals, all with distinct tissue and developmentally specific expression, distinct kinetics, with alternative substrate specificity...

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 ...

The capacity of the adrenal to produce cortisol is controlled in part by the transcription of 21 hydroxylase(CYP21) and production of androgens by 17 hydroxylase/17-20 lyase(CYP17) in response to secretogoues including ACTH, angiotensin-II(A-II) and forskolin. Both mRNA and protein expression of CYP21 was upregulated in the presence of forskolin and A-II alone and in combination in vitro H-295 adrenocortical cells, as detected by northern and western blotting. Whereas, ...

Objective We aimed to immunopurify GnSAF, using antibodies with demonstrated GnSAF bioactivity-blocking/binding activity, in order to confirm 2 new candidate amino acid sequences for human ovarian GnSAF (Fowler et al. Mol Human Reprod 2002;8:823-832).Methods Rat antiserum, raised against a 60-70 kDa band of partially purified GnSAF, was immobilised on anti-rat IgG Dynabeads. In addition, a human antibody, derived from a phage display antibody library a...