Endocrine Abstracts

Background: Aldosterone levels in plasma are reported to be associated with risk of hypertension. Aldosterone secretion from the zona glomerulosa is regulated acutely by the renin/angiotensin system and plasma potassium. The role of ACTH in regulation of aldosterone secretion is disputed.Aim: We have utilised a large population study of middle aged adults to test the extent to which acute aldosterone responses to ACTH are associated with cortisol respons...

We have previously shown that the ACTH precursor, POMC, is present in human plasma and is the predominant secreted POMC peptide. This suggests that POMC processing is incomplete in neuroendocrine cells and regulation of the post-translational cleavage pathway is important in controlling secretion of ACTH. We have therefore analysed the dynamics of POMC processing in both AtT20 pituitary adenoma cells and primary rat pituitary cells. In both cases, large quantities of POMC, as ...

Annexin A1 (ANXA1), a Ca2+ and phospholipid binding protein, serves as a paracrine/justacrine mediator of glucocorticoid action in the neuroendocrine system. Within the anterior pituitary gland ANXA1 is produced by folliculo-stellate (FS) cells and, following serine-27 phosphorylation (Ser27-P) and membrane translocation, acts on adjoining corticotroph cells to suppress ACTH release via a mechanism involving formyl peptide receptor (FPR) activation. To ex...

The rise in the prevalence of obesity has imparted urgency to the study of the mechanisms of appetite regulation. Oxyntomodulin (OXM) and glucagon-like peptide-1 (GLP-1) are anorexigenic gut hormones thought to act via the same receptor. There is an increasing body of evidence, however, that they may act via distinct pathways. Magnetic resonance imaging (MRI) is increasingly being used as a tool for tracking changes in neuronal activity in vivo through time. Manganese-e...

Background: Proopiomelanocortin gene (POMC) and its cleaved product adrenocorticotrophin hormone (ACTH) play an important role in regulation of the hypothalamo-pituitary-adrenal (HPA) axis. ACTH stimulates the adrenal glands to release glucocorticoids. Glucocorticoid has a suppressive effect on ACTH and POMC. This suppression remains long after withdrawal, and may lead to adrenocortical insufficiency. POMC expression is dependent on the activities of some of the positively act...

Preantral follicle development in polycystic ovaries (PCO) is characterised by an increased proportion of early growing follicles. We have previously shown that IGF-1 stimulates initiation of follicle growth in normal and PCO (Endocrine Abstracts 2004 7 P172). Here we have extended these studies, specifically to examine whether the ovulatory status of the patients from whom tissue is obtained influences the response to IGF-1. Small ovarian biopsies were obtained (with ethical ...

Aldosterone is key in the development of hypertension. We have shown that a SNP (−344T) in the 5’ regulatory region (UTR) of the gene encoding aldosterone synthase (CYP11B2) was associated with aldosterone excess and high blood pressure. However, the most robust phenotype is altered adrenal 11-hydroxylation efficiency (deoxycortisol to cortisol); a step carried out by 11β-hydroxylase, encoded by the adjacent gene, CYP11B1. We proposed that the effects of CYP11B...