Endocrine Abstracts

Annexin 1 (Anx-1), a 37kDa protein, is a member of the super-family of Ca 2+ and phospholipid-binding annexin proteins and acts as a mediator of glucocorticoid (GC) action in the host defense 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. It has been previously demonstrated that TtT/GF...

Annexin A1 (AnxA1) acts as a mediator of glucocorticoid (GC) actions in 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 release of ACTH and other pituitary hormones. GC cause the externalization of AnxA1. The stress responsiveness of the female rat hypothalamo-pituitary-adrenal system varies with the estrous cycle, with increased CORT release in resp...

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. Consistent with these findings plasma PRL content is raised in male ANXA1 null mice vs wild-type controls (Cover et al Endocrine Abstracts 8, P69). Here we test the hypothesis that because ANXA1 mediates some of the inhibitory actions of ...

Animal and clinical models of GHRH excess suggest that GHRH provides an important trophic drive to pituitary somatotrophs. Mice in which GHRH neurons have been ablated using a novel viral ion channel transgene (GHRH-M2 mice) show marked anterior pituitary hypoplasia and GH deficiency although GH cells are present. GHRH-M2 mice are also deficient in prolactin which is surprising as GHRH has little or no direct effect on PRL synthesis or release (Le Tissier, Mol Endo 19). In mic...

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...

Mouse distal Chromosome 2 has a proximal region containing a single imprinted gene, Neuronatin, Nnat. In situ hybridisation has shown strong expression of neuronatin in the embryonic mouse Rathke's pouch and primordial anterior pituitary (Wijnholds et al 1995, Dev Biol 171:73-84) and has been proposed to participate in pituitary development. Uniparental maternal inheritance of the proximal region leads to decreased folding of the cerebellum (Kikyo et al 1997, Dev Biol 190:66-7...

Prolactin secretion is sexually dimorphic and sensitive to changes in gonadal steroid and glucocorticoid status. Reports that the regulatory effects of glucocorticoids on prolactin release are mediated in part via annexin 1 (ANXA1, 1), have led us to compare prolactin secretion and lactotroph morphology in ANXA1 knockout (KO) and wildtype (WT) mice and to determine the effects gonadectomy +/- testosterone replacement (80 micrograms per day, s.c.) on (a) the plasma prolactin co...