Endocrine Abstracts

Calcium mobilization from intracellular stores represents an important cell signalling process that is regulated, in mammalian cells, by inositol-1,4,5-triphosphate (IP3), cyclic ADP ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP). Intracellular calcium is important for mobilization of secretory granules to the plasma membrane in preparation for exocytosis. NAADP mobilizes calcium from lysosome-related acidic compartments and it has recently...

Folliculo-stellate (FS) cells exert a paracrine regulation on their neighbouring endocrine cells in the anterior pituitary gland. FS cells are non-granular cells characterized by long cytoplasmic processes and form follicles with microvilli on their luminal cavity, suggesting a transport function. Moreover, FS cells form monolayers in primary culture and develop domes after reaching confluence, characteristics of polarized transport epithelia. However little is known about tra...

Recent studies have demonstrated that rather than being a collection of heterogeneously dispersed cells, the pituitary gland is wired by multiple and specific endocrine cell networks to synchronise hormone release. Prolactin (PRL) is primarily important for lactation. In response to changing physiological demands during pregnancy and lactation the pituitary has the ability to expand and contract its cell number. We have investigated changes in lactotroph morphology and cell-to...

Annexin 1 (ANXA1) was first identified as a glucocorticoid (GC)-inducible protein in macrophages and is a mediator of the powerful anti-inflammatory actions of these steroid hormones. In the pituitary ANXA1 plays a critical role in mediating the early-onset negative feedback effects of GCs on the release of ACTH. ANXA1 is expressed in abundance in the anterior pituitary gland where it is localized specifically to the S100-positive folliculo-stellate (FS) cells. GCs act on FS c...

Annexin 1 (ANXA1) externalised from folliculostellate cells is known to be an essential intermediate in the early delayed (30 min- 3 h) negative feedback of glucocorticoids on the release of ACTH and other pituitary hormones. We have used a well-characterised folliculostellate cell line (TtT/GF cells) to investigate the mechanism by which ANXA1, a cytoplasmic protein, is externalised by cells. Externalisation is stimulated by dexamethasone (Dex) and inhibited by inhibitors of ...

Annexin 1 (ANXA1) is a 37 Kd member of the annexin family of Ca2+− and phospholipid binding proteins that has been well demonstrated to act as a mediator of glucocorticoid action in inflammation and in the control of anterior pituitary hormone release. ANXA1 is also proapoptotic and has been identified as a mediator of apoptotic cell engulfment (Solito et al. 2003 FASEB J 17:1544; Arur et al. 2003 Dev Cell 4:587). Using yeast two hybrid screening...

Annexin 1 (ANXA1) is a glucocorticoid-regulated, calcium and phospholipid-binding protein well recognized as an important signalling intermediate in both peripheral systems and the brain. Online adult mouse brain gene libraries have reported ANXA1 mRNA expression in the subventricular zone (SVZ) lining the lateral ventricles. The SVZ is one of the two largest neurogenic areas of the brain and as ANXA1 plays a known role in cell differentiation and proliferation, we have invest...

Annexin-1 (ANXA1) is a 37 kDa calcium- and phospholipid-binding protein expressed abundantly in S100-positive folliculostellate (FS) cells in the anterior pituitary gland. ANXA1 is localised both intracellularly and on the cell surface in high density foci appearing at points of contact between the FS cells and the neighbouring secretory cells, where it has been demonstrated to mediate the glucocorticoid-induced negative feedback on the secretion of ACTH from corticotrophs. Gl...

Our initial studies suggested that plurihormonal cells are constantly found in early embryonic stages of human pituitary but are very rare later.Aim: A quantitative evaluation and morphological characterization of these plurihormonal cells.Methods: Pituitaries from therapeutically aborted human fetuses of 8–24 weeks, gestational age were fixed (with ethical permission) by immersion in 4% buffered formaldehyde. One-μm-thic...

CD38 is an enzyme which catalyses the production of the second messengers cyclic ADP ribose and nicotinic acid adenine dinucleotide phosphate which mobilize calcium from ryanodine-sensitive intracellular calcium stores. Intracellular calcium is well known to be important for mobilisation of secretory granules to the plasma membrane in preparation for exocytosis and CD38 signalling has recently been demonstrated to increase posterior pituitary oxytocin release (Jin et al.</i...