Endocrine Abstracts

Aims: To define the ultradian pattern of corticosterone secretion in the rat, how this may be altered in different physiological states and the relevance of these patterns to nuclear signalling in the hippocampus.Methods: Rats were cannulated and attached to our automated blood sampling system. Some rats had simultaneous intracranial microdialysis for free corticosterone in the hippocampus and other rats were adrenalectomised and corticosterone replaced ...

Glucocorticoids have profound effects on the brain, particularly during development and during the ageing process. The glucocorticoid metabolising enzymes, 11beta-hydroxysteroid dehydrogenases (11β-HSDs) type 1 and 2, interconvert active corticosterone (or cortisol) and inactive 11keto-derivatives to modify intracellular glucocorticoid levels. Hence, these enzymes add another layer of complexity to glucoocorticoid action in addition to circulating hormone and receptor (MR...

The seminal studies of Harvey Cushing informed us of the deleterious consequences of circulating cortisol excess – hypertension, osteoporosis and obesity that contributes to diabetes and premature mortality. As such Cushing’s syndrome offers an excellent paradigm for the metabolic syndrome. However circulating cortisol concentrations are invariably normal in patients with metabolic syndrome. The tissue-specific generation of cortisol, independent of circulating level...

Glucocorticoids act within the pituitary gland to maintain the blood levels of glucocorticoids within appropriate limits by negative feedback on the secretion of corticotrophin (ACTH). Annexin 1 (ANXA1) is a calcium- and phospholipid binding protein which was originally identified as a mediator of the anti-inflammatory actions of glucocorticoids in the host defence system. Subsequent work has shown that it that plays an important role in the early delayed (30 min-3 h) feedback...