Endocrine Abstracts

Knockout studies have demonstrated that FSHbeta knockout (FSHbKO) and FSH receptor knockout (FSHRKO) female mice are infertile due to block of follicle development at the pre-antral stage. The ovaries are reduced in size and uteri are atrophic. However, a proportion of FSHRKO and FSHbKO mice develop ovarian and uterine hypertrophy in middle age (Abel et al, 2001). In order to investigate further brain-pituitary-gonadal interrelationships the aim of the present study was to com...

Annexin-1 (Anx-1), a 37 kDa protein, is a member of the super-family of Ca2+and phospholipid-binding annexin proteins and acts as a mediator of glucocorticoid (GC) action in the host defence and neuroendocrine systems. In the anterior pituitary Anx-1 is expressed mainly by folliculostellate (FS) cells and mediates the early-delayed feedback inhibition exerted by GCs on the release of ACTH and other pituitary hormones.The stress responsiveness ...

Annexin-1 (Anx-1), a 37kDa protein, is a member of the super-family of Ca2+- and phospholipid-binding annexin proteins and acts as a mediator of glucocorticoid (GC) action in the host defence and neuroendocrine systems. In the anterior pituitary Anx-1 is expressed mainly by folliculostellate (FS) cells and mediates the early delayed feedback inhibition exerted by GCs on the release of ACTH and other pituitary hormones.The role of Anx-1 in the ...

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...

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...

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...

Annexin 1 (ANXA1) plays an essential role in the 'early-delayed' feedback effects of glucocorticoids (GCs) on ACTH release. Evidence that ANXA1 is externalised from pituitary cells in response to GCs, together with the finding that the protein is localised mainly to the folliculo-stellate (FS) cells, has led us to propose that ANXA1 is a paracrine mediator of GC action in the anterior pituitary. To address this hypothesis we have examined ANXA1-dependent GC actions in co-cultu...

Annexin I, a phospholipid and calcium binding protein, plays a well demonstrated role in the early delayed inhibitory feedback actions of glucocorticoids in the pituitary. Annexin I is localized in folliculostellate (FS) cells and glucocorticoids act on these cells to externalize annexin I at specific foci on FS cell processes (Chapman et al, 2002 Endocrinology, in press). Annexin I lacks a signal sequence to direct it into the secretory pathway and the foci of externalized an...