Endocrine Abstracts

Stafford Lightman is Professor of Medicine at the University of Bristol and is Director of the Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology. He started his scientific career working on catecholamines and opioid peptides with Leslie Iversen at the University of Cambridge and provided some of the first data linking opioid peptides with the regulation of neurohypophysial function. At this time he also performed some of the first studies demonstrating...

Pituitary and adrenal gland assessment, is one of the most important aspects of the management of a pituitary and adrenal adenoma.Clinical practice varies widely with regard to assessment of pituitary and adrenal status pre- and post-operative. Pre-operative testing includes dynamic testing to assess function which is not practical in the immediate post-operative period. Instead a single morning serum total hormones are measured while a more definitive a...

Actions of the stress hormone, glucocorticoid (GC), are essential for the modulation of implicated biological processes such as synaptic transmission. In disease paradigms that feature a hormone hyper-secretion phenotype (e.g. neurocognitive disorders), the normalcy of receptor signaling is compromised.The pro-cognate role of Glucocorticoid receptor (GR) inhibition via hormone analogues bearing anti-glucocorticoid properties is well described. A key exam...

Biological systems are invariably dynamic, with both stochastic interactions and deterministic processes across multiple timescales ensuring the maintenance of homeostatic regulation and allowing us to adapt to changes in both internal and external environments. It is no surprise therefore that the stress responsive hypothalamic-pituitary-adrenal (HPA) axis shows multiple levels of regulation which come together to regulate oscillating levels of glucocorticoid secretion with b...

The circadian variation of hypothalamo-pituitary-adrenal (HPA) activity is well recognised, with levels of glucocorticoid rising in anticipation of the activity of the coming day (in humans) or night (in rodents). Less well recognised however, is that in common with many other hormones, both ACTH and corticosteroids are released in a pulsatile pattern – with the largest pulses occurring in the morning in man – explaining the large range of ‘normal’ morning ...

The HPA axis has a massive dynamic response rate. At nadir periods (at night in man and during the day in nocturnal rodents) there is a low level of activity which increases up until the circadian peak. This circadian rhythm is made up of an underlying ultradian rhythm of pulsatile glucocorticoid section, with pulse amplitude increasing from the circadian nadir to the circadian peak. Superimposed on this underlying rhythm is, of course, the stress response which can result in ...

Whereas it was previously accepted that patients needed between 20 and 30mg of hydrocortisone daily, current estimates are much lower at approximately 10mg per day. The next question - which appears uncontroversial - is the choice of drug. This is universally accepted as being hydrocortisone. But is it? The adrenal glands secrete both cortisol and cortisone and there is now increasing evidence that 11betaHSD-1 can, in a tissue-specific manner, convert cortisone to cortisol. Th...

BackgroundStress responsiveness is mediated through sympathetic and hypothalamic-pituitary-adrenal axis activation. The gold standard investigation is the plasma catecholamine and cortisol response to the insulin tolerance test (ITT). This is invasive, and the use of salivary surrogates for stress responses would be a great advance.ObjectiveDemonstrate whether salivary alpha-amylase is a potential surrogate m...

The Pituitary Foundation was founded in 1994 when a group of endocrinologists, GPs and patients identified the need for a support group for patients with pituitary disease. Charitable status followed in 1996. It's core aims are to provide support to patients, their families and carers, to act as a source of reliable information and to increase awareness of the Foundation and pituitary disease within the medical profession and the general public. Membership, services and public...

Glucocorticoid hormones (cortisol in man, corticosterone in rodent; CORT) are vital for maintaining normal homeostasis in multiple systems ((e.g., the cardiovascular, metabolic, and immune systems), and for an optimal response to acute and chronic stress. Plasma CORT is released from the adrenal zona fasciculata (ZF) in response to circulating levels of pituitary-derived adrenocorticotropin hormone (ACTH). ACTH binds to the MC2-receptor on the membra...