Endocrine Abstracts

Conservation is a tricky subject to discuss when people actually are asked to consider the present situation, and the virtual world that many live in today. Many of the losses of species are due to human intervention, through killing for pleasure, food, or profit (greed), or through habitat destruction. The species are innocent. Zoos provide a sanctuary for maintaining some numbers of species on a limited scale, but can only ever be a stop-gap to maintain the species, although...

Birth of a single baby gives that infant the best possible start to life. In mono-ovular species like man there is a tight control over the hypothalamic–pituitary–ovarian axis to try to ensure that there is also sufficient time between births to allow the infant to develop to its full potential. Breastfeeding suppresses fertility by modulating pulsatile LH but not FSH secretion delaying the final stages of ovarian follicle maturation and the return of fertility in br...

Alan McNeilly, MRC Human Reproduction Sciences Unit, Edinburgh, UK AbstractAfter graduating from Nottingham (BSc) and Reading (PhD) Universities with degrees in animal physiology, Dr McNeilly joined Tim Chard at Barts for 4 years developing gonadotrophin and prolactin assays for clinical application. During those 4 years he gained experience in clinical endocrinology. Collaborations with Roger Short and David Baird led...

Within target cells, cortisol-cortisone inter-conversion is catalysed by both a NADP(H)-dependent, bidirectional type 1 11β-hydroxysteroid dehydrogenase (11βHSD1) enzyme and by a NAD+-dependent, unidirectional type 2 11βHSD (11βHSD2) isoenzyme. Since several published studies have reported altered glucocorticoid metabolism in polycystic ovary syndrome (PCOS), the current study assessed whether prenatal exposure of lambs to testosterone propionate...

The intraperitoneal environment of the ovarian surface epithelium (OSE) has an oxygen (O2) tension of 5–12%. This could impact cellular events leading to ovulation. Furthermore, ovarian cancers arising from the OSE (∼80–90% of ovarian malignancies) are likely to experience increased hypoxia due to the relatively poor vascularisation of solid tumours.Using 1%, 5% or 20% O2, we measured the expression of HSD11B1, COX-2...

Circulating levels of prolactin are subject to acute and long-term regulation by many factors including oestrogen and dopamine. We have studied the regulation of prolactin promoter activity in living pituitary cells using transgenic Fischer rats in which reporter gene expression is regulated by the human prolactin gene locus (hPRL-d2EGFP). We have previously identified pulsatile prolactin transcription patterns in living lactotroph cells in fetal tissue, that became stabilised...

Pituitary development, in particular the differentiation of anterior pituitary endocrine cells, remains to be fully understood, and may have implications for adult pituitary plasticity and hyperplasia. We have used prolactin-reporter transgenic rats to characterise prolactin transcription during the appearance of newly formed lactotroph cells during fetal development.Transgenic rats with the firefly luciferase reporter gene inserted into exon 1b of a 160...

We have created transgenic mice in which Cyp11b1, the gene encoding 11β-hydroxylase, has been knocked out. Since mice do not secrete adrenal androgens, this knockout line allows a more detailed investigation of phenotypes associated with congenital adrenal hyperplasia (CAH) without the overwhelming virilisation that characterises patients with CAH. Starting with a BAC containing the mouse Cyp11b1/b2 locus and including flanking up- and downstream sequences, a const...

Mammalian genes display pulsatile transcription dynamics with bursts of expression occurring with variable duration and frequency. Using the human prolactin gene as a model of tissue specific gene regulation, we have characterised the transcription dynamics of this gene in cell lines, primary cells and pituitary tissue slices. Our data indicate that the tissue environment may have an important influence on cellular transcription activity. Cultures of cells from enzymatically d...

Prolactin (PRL) is a peptide hormone produced by the anterior pituitary gland and it is commonly known for its lactogenic and mammotrophic effects. In humans and primates, prolactin is also expressed in extra-pituitary sites where it is associated with numerous biological functions, but its spectrum of expression varies in different species.Hyperprolactinemia-induced osteoporosis is believed to be mediated by hypogonadism, but the expression of the prola...