Adrenocortical Disease
T.M. Craft, P.M. Upton in Key Topics In Anaesthesia, 2021
The adrenal cortex produces glucocorticoid, mineralocorticoid and sex hormones (mainly testosterone). Cortisol, the principal glucocorticoid, modulates stress and inflammatory responses. It is a potent stimulator of gluconeogenesis and antagonizes insulin. Aldosterone is the principal mineralocorticoid. It causes increased sodium reabsorption, and potassium and hydrogen ion loss at the distal renal tubule. Adrenal androgen production increases markedly at puberty, declining with age thereafter. Androstenedione is converted by the liver to testosterone in the male and oestrogen in the female. Cortisol and androgen production are under diurnal pituitary control (adrenocorticotrophic hormone — ACTH). Aldosterone is released in response to angiotensin II, produced following renal renin release and subsequent pulmonary angiotensin I conversion.
The Renin-Angiotensin System
Austin E. Doyle, Frederick A. O. Mendelsohn, Trefor O. Morgan in Pharmacological and Therapeutic Aspects of Hypertension, 2020
Aldosterone is the most potent natural mineralocorticoid and promotes renal sodium retention with consequent expansion of extracellular sodium and fluid volume.389 There is also clear evidence that excessive secretion of aldosterone can lead to arterial hypertension, and exemplified by primary aldosteronism.390 These observations lead to a plausible mechanism whereby raised levels of angiotensin might stimulate aldosterone secretion, thereby promoting sodium retention and contributing to the hypertension. This sequence of events has been assumed to be operative in hypertensive states associated with hyperactivity of the renin-angiotensin system. It has been proposed that sodium retention partly induced by aldosterone hypersecretion contributes to the early stage of renal hypertension by expansion of extracellular fluid volume, increased cardiac output, and autoregulatory vasoconstriction.391,392 There is experimental evidence for this proposal in some,393-396but not all,397 studies of the hemodynamics during the onset of experimental renal hypertension. This mechanism is clearly not essential for the chronic pressor effect of angiotensin II, since progressive hypertension still occurs in adrenalectomized rabbits which were infused with low doses of angiotensin II.398
The Internal Milieu Brain and Body
Rolland S. Parker in Concussive Brain Trauma, 2016
Cortisol: Exerts a permissive action for many hormones, in addition to its own direct effects. Cortisol is involved in negative feedback, limiting feedback of its own production at the hypothalamic (CRH) and anterior pituitary levels (ACTH). Parathyroid hormone: Regulates calcium and phosphorus levels.Vasopressin: Regulates serum osmolality by controlling renal water clearance.Mineralocorticoids: Control vascular volume and serum electrolyte (Na+ and K+) concentrations.
Vaccination and their importance for lung transplant recipients in a COVID-19 world
Published in Expert Review of Clinical Pharmacology, 2021
Samantha Scharringa, Thijs Hoffman, Diana A. van Kessel, Ger T. Rijkers
Corticosteroids are a group of compounds that mimic the endogenous steroid hormones produced in the adrenal cortex. Corticosteroids are divided into two classes: mineralocorticoids which regulate electrolyte and fluid homeostasis, and glucocorticoids which have anti-inflammatory properties [7]. Some of the most commonly prescribed glucocorticoids are prednisone and dexamethasone. Although dexamethasone has been found to be seven times more potent than prednisone on a weight for weight basis, it also has more side effects. Due to this fact, dexamethasone has been reserved for patients who do not respond to prednisone or whose symptoms cannot be controlled by prednisone [8]. In transplant medicine, corticosteroids are used to prevent organ rejection by starting at high doses after surgery and slowly tapering to a reach a maintenance dose.
‘Drink clean, safe water and/or other fluids through-out the day even if you do not feel thirsty’: a food-based dietary guideline for the elderly in South Africa
Published in South African Journal of Clinical Nutrition, 2021
Upasana Mukherjee, Carin Napier, Wilna Oldewage-Theron
The most important hormones in the maintenance of body fluid levels are part of the renin-angiotensin system. In response to extracellular fluid loss, rennin is secreted and it increases water uptake and retention by the kidneys. Renin also stimulates the secretion of angiotensin, which induces thirst sensations through the hypothalamus of the brain. With the progression of age, the rennin function is lowered and the kidneys lose the ability to concentrate urine. Angiotensin stimulation of thirst may also be impaired as studies on rats reported that adding angiotensin stimulants in drinks does not increase thirst in the elderly as it would normally do in younger animals.13,27 The second important set of hormones regulating water balance are part of the arginine vasopressin system. Vasopressin is called the antidiuretic hormone because of its potent ability to increase fluid retention in the kidneys. Aldosterone is a mineralocorticoid that primarily regulates sodium balance in the kidneys by stimulating sodium reabsorption and potassium excretion. Both secretion and sensitivity of the hormone is reduced due to ageing.13,27,52
An up-to-date evaluation of abiraterone for the treatment of prostate cancer
Published in Expert Opinion on Pharmacotherapy, 2021
Jason Shpilsky, Julia Stevens, Glenn Bubley
Mineralocorticoid excess syndrome (MES) is a key on–target effect of abiraterone (Figure 1). By inhibiting CYP17A1, abiraterone reduces production of downstream DHEA and testosterone. However, inhibition of CYP17A1 also reduces production of cortisol, which decreases negative feedback to the pituitary, increasing levels of ACTH [16]. This causes an increase in the mineralocorticoid deoxycorticosterone, leading to hypokalemia, hypertension, and fluid retention. Coadministration of glucocorticoids suppresses ACTH and prevents MES. Abiraterone is approved with concomitant prednisone 5 mg twice daily (mCRPC) or prednisone 5 mg daily (mCSPC) [18]. One randomized phase II trial found that prednisone 5 mg twice daily had higher rates of freedom from MES compared to prednisone 5 mg daily (71% vs 37%), without significant impacts on insulin resistance or bone mineral density [32]. A corticosteroid regimen should be selected and adjusted based on a patient’s comorbidities and presence of MES.
Related Knowledge Centers
- Adrenal Cortex
- Deoxycorticosterone
- Potassium
- Progesterone
- Sodium
- Steroid Hormone
- Corticosteroid
- Aldosterone
- Fluid Balance
- Mineral