Endocrine Abstracts

VEGF (vascular endothelial growth factor) is an endothelial cell mitogen responsible for physiological and pathophysiological angiogenesis. Abnormal regulation of VEGF expression in anterior pituitary folliculostellate (FS) cells has been implicated in pituitary tumour progression. PACAP is a well-documented stimulant of VEGF secretion from the pituitary in which both FS and endocrine cells express VEGF. TtT/GF cells are a mouse pituitary cell line with many characteristics of...

Annexin 1 (ANXA1) is a member of the annexin family of phospholipid- and calcium- binding proteins with a well-demonstrated role in the inhibitory actions of glucocorticoids on the release of ACTH, TSH, GH and PRL from the anterior pituitary. ANXA1 and ANXA1 truncated peptides have also recently been found to mimic glucocorticoid suppression of LH release (John et al, 2003 J Neuroendocrinol 15, 946-57). Here we test the hypothesis that because ANXA1 mediates some of the inhibi...

Hypogonadism is difficult to confirm with standard assays. A large proportion of testosterone (T) is bound to sex hormone binding globulin (SHBG) and is biologically inert. Accurate measures of free and biological-available-testosterone (Bio-T) are largely unavailable. In this study we compared formulae calculated from the total testosterone (TT) and SHBG in their ability to predict hypogonadism and/or Bio-T.TT and SHBG were determined by ELISA and Bio-T...

It has been postulated that ACTH might modulate its own secretion by a negative feedback loop and we have recently found that the ACTH receptor (MC2R) is present in both normal and tumorous human corticotrophs. In this study we investigated the expression of the ACTH receptor in mouse and rat pituitary tissue as well as mouse pituitary tumour (AtT20) cells and studied the effect of Synacthen (ACTH [1-24]) on ACTH secretion, cAMP release and cell proliferation in AtT20 cells. M...

It has been noted that there are differences in the hypothalamic-pituitary-adrenal (HPA) axis between the sexes, as well as changes in the axis with age. The differences in the HPA axis between the gender and age groups are thought to be due to differences in the efficiency of glucocorticoid (GC) negative feedback. The pituitary, a principle site of GC negative feedback, is the focus of this investigation. Annexin-1 (ANXA1) is a member of the annexin family of phospholipid- an...

BACKGROUNDAngina and Myocardial infarction have been reported in hyperthyroidism. Intense coronary artery spasm can be life threatening as it can lead to ventricular fibrillation and haemodynamic instability as reported in this patient.CASE HISTORYA 45-year-old lady was admitted with a history of head aches, palpitations, diarrhoea and weight loss. She was subsequently found to have thyrotoxicosis with the th...

Background: The objective of this study was to define the incidence and prevalence of treated thyroid dysfunction in a complete and representative population base.Method: We used record-linkage technology to retrospectively identify subjects treated for hyperthyroidism or hypothyroidism in the general population of Tayside, Scotland from 1 January 1993 to 30 April 1997. Thyroid status was ascertained by record-linkage of patient-level datasets containing...

Immunoneutralisation and antisense studies have shown that the acute regulatory actions of glucocorticoids (GCs) on the secretion of corticotrophin (ACTH) from the anterior pituitary gland are dependent upon the 37 kDa protein, annexin 1 (Anxa1 [1]), which is localised mainly to the S100-positive folliculo-stellate (FS) cells that lie in close apposition with the endocrine cells. The aim of this study was to examine pituitary function in male and female mice lacking the Anxa1 ...

Annexin 1 (ANXA1) is a Ca 2+ and phospholipid binding protein that plays an important role as a mediator of glucocorticoid (GC) action in the host-defence and neuroendocrine-systems. Our previous studies (Christian et al., 1998) in ovarietomised rats +/- oestradiol (E2) replacement suggested oestrogen may exert an inhibitory influence on ANXA1 expression in the pituitary gland. Our more recent finding that ANXA1 knockout mice exhibit unexpected sexual dimorphisms in...

The activin-binding protein follistatin is produced by folliculostellate (FS) cells of the anterior pituitary. FS cells make numerous contacts with the classical endocrine cells of the anterior pituitary including gonadotrophs. Follistatin released from the FS cells could therefore play a role in the regulation of gonadotrophin secretion, in particular of FSH. We have previously shown by confocal microscopy (1) that annexin 1, which is also produced by FS cells, is secreted fr...