Endocrine Abstracts

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 ...

Acknowledgements: This work was generously supported by the Wellcome TrustAnnexin 1 (ANXA1) plays an important role in mediating the negative feedback effects of glucocorticoids on the HPA axis. It is released from non-secretory folliculostellate (FS) cells by glucocorticoids and acts locally to suppress ACTH release from corticotrophs. Previous studies suggest that the steroid-induced translocation of ANXA1 across the FS cell membrane is effected via me...

Annexin 1 (ANXA1) plays an important role in mediating the negative feedback effects of glucocorticoids on the HPA axis. In the anterior pituitary gland ANXA1 is localised mainly to the non-secretory folliculostellate (FS) cells. It is released from these cells by glucocorticoids and acts locally to suppress ACTH release from corticotrophs. Functional and histological studies suggest that the steroid-induced translocation of ANXA1 across the FS cell membrane is effected via me...

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 ...

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...

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...

Radioiodide therapy of thyroid cancer represents the most effective form of systemic radiotherapy available to the clinician today. The ability of thyroid cancer cells to concentrate iodide is induced by expression in the follicular cell membrane of the sodium iodide symporter, NIS. Some thyroid cancers lack expression of this protein and therefore the ability to concentrate iodide, making them insensitive to 131-I therapy. Several investigators have characterized the expressi...

Nitric oxide (NO) is a regulator of pituitary gonadotrophs via local paracrine and autocrine actions. Gonadotrophs express neuronal nitric oxide synthase (nNOS) but the effects of NO on gonadotrophs are controversial and both stimulation and inhibition of LH release has been reported. nNOS -/- mice have reduced fertility, but this is attributed to ovary actions, because no difference was detected in basal or GnRH-stimulated LH release (Klein et al 1998). We have therefore exam...

Hereditary nephrogenic diabetes (di/di) in mice results from a failure of vasopressin (VP)action caused by overactive renal cAMP phosphodiesterase activity. The adult animals pass large amounts of dilute (100 mOsm per kg) urine and have hyperosmotic plasma (40 mOsm per kg greater than wild-type). Their osmotic status is therefore similar to that in Brattleboro rats in which both VP and oxytocin (OT) neurons are hyperactive and the neural lobe is depleted of both OT and VP. 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...