The adrenal glands are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla. The adrenal cortex itself is divided into three main zones: the zona glomerulosa, the zona fasciculata and the zona reticularis.
Endocrinology is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the integration of developmental events proliferation, growth, and differentiation, and the psychological or behavioral activities of metabolism, growth and development, tissue function, sleep, digestion, respiration, excretion, mood, stress, lactation, movement, reproduction, and sensory perception caused by hormones. Specializations include behavioral endocrinology and comparative endocrinology.
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involved in a wide range of physiological processes, including stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior.
Cortisone is a pregnane (21-carbon) steroid hormone. Cortisone is a synthetic corticosteroid, which is not released by the adrenal gland. In chemical structure, it is closely related to cortisol, a substance which is released by the adrenal gland. It is used to treat a variety of ailments and can be administered intravenously, orally, intra-articularly, or transcutaneously. Cortisone suppresses the immune system, thus reducing inflammation and attendant pain and swelling at the site of the injury. Risks exist, in particular in the long-term use of cortisone.
Edward Calvin Kendall was an American chemist. In 1950, Kendall was awarded the Nobel Prize for Physiology or Medicine along with Swiss chemist Tadeusz Reichstein and Mayo Clinic physician Philip S. Hench, for their work with the hormones of the adrenal gland. Kendall did not only focus on the adrenal glands, he was also responsible for the isolation of thyroxine, a hormone of the thyroid gland and worked with the team that crystallized glutathione and identified its chemical structure.
Philip Showalter Hench was an American physician. Hench, along with his Mayo Clinic co-worker Edward Calvin Kendall and Swiss chemist Tadeus Reichstein was awarded the Nobel Prize for Physiology or Medicine in 1950 for the discovery of the hormone cortisone, and its application for the treatment of rheumatoid arthritis. The Nobel Committee bestowed the award for the trio's "discoveries relating to the hormones of the adrenal cortex, their structure and biological effects."
Addison's disease, also known as primary adrenal insufficiency and hypocortisolism, is a rare long-term endocrine disorder characterized by inadequate production of the steroid hormones cortisol and aldosterone by the two outer layers of the cells of the adrenal glands, causing adrenal insufficiency. Symptoms generally come on slowly and may include abdominal pain and gastrointestinal abnormalities, weakness, and weight loss. Darkening of the skin in certain areas may also occur. Under certain circumstances, an adrenal crisis may occur with low blood pressure, vomiting, lower back pain, and loss of consciousness. Mood changes may also occur. Rapid onset of symptoms indicates acute adrenal failure which is a serious and emergent condition. An adrenal crisis can be triggered by stress, such as from an injury, surgery, or infection.
Aldosterone is the main mineralocorticoid steroid hormone produced by the zona glomerulosa of the adrenal cortex in the adrenal gland. It is essential for sodium conservation in the kidney, salivary glands, sweat glands, and colon. It plays a central role in the homeostatic regulation of blood pressure, plasma sodium (Na+), and potassium (K+) levels. It does so primarily by acting on the mineralocorticoid receptors in the distal tubules and collecting ducts of the nephron. It influences the reabsorption of sodium and excretion of potassium (from and into the tubular fluids, respectively) of the kidney, thereby indirectly influencing water retention or loss, blood pressure and blood volume. When dysregulated, aldosterone is pathogenic and contributes to the development and progression of cardiovascular and kidney disease. Aldosterone has exactly the opposite function of the atrial natriuretic hormone secreted by the heart.
Tadeusz Reichstein was a Polish-Swiss chemist and the Nobel Prize in Physiology or Medicine laureate (1950).
Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by impaired cortisol synthesis. It results from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cortex. Most of these disorders involve excessive or deficient production of such hormones as glucocorticoids, mineralocorticoids, or sex steroids, and can alter development of primary or secondary sex characteristics in some affected infants, children or adults. It is one of the most common autosomal recessive disorders in humans.
Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones, primarily cortisol; but may also include impaired production of aldosterone, which regulates sodium conservation, potassium secretion, and water retention. Craving for salt or salty foods due to the urinary losses of sodium is common.
Congenital adrenal hyperplasia due to 17α-hydroxylase deficiency is an uncommon form of congenital adrenal hyperplasia resulting from a defect in the gene CYP17A1, which encodes for the enzyme 17α-hydroxylase. It causes decreased synthesis of cortisol and sex steroids, with resulting increase in mineralocorticoid production. Thus, common symptoms include mild hypocortisolism, ambiguous genitalia in genetic males or failure of the ovaries to function at puberty in genetic females, and hypokalemic hypertension (respectively). However, partial (incomplete) deficiency is notable for having inconsistent symptoms between patients, and affected genetic (XX) females may be wholly asymptomatic except for infertility.
11β-Hydroxysteroid dehydrogenase enzymes catalyze the conversion of inert 11 keto-products (cortisone) to active cortisol, or vice versa, thus regulating the access of glucocorticoids to the steroid receptors.
11-Deoxycorticosterone (DOC), or simply deoxycorticosterone, also known as 21-hydroxyprogesterone, as well as desoxycortone (INN), deoxycortone, and cortexone, is a steroid hormone produced by the adrenal gland that possesses mineralocorticoid activity and acts as a precursor to aldosterone. It is an active (Na+-retaining) mineralocorticoid. As its names indicate, 11-deoxycorticosterone can be understood as the 21-hydroxy-variant of progesterone or as the 11-deoxy-variant of corticosterone.
Derek Ashworth Denton is an Australian scientist who explained the regulation of electrolytes in extracellular fluid, the hormones controlling this regulation, particularly aldosterone, and the instinctive behaviours controlling intake of water and salts. He was cited in 1995 at election to the U.S. National Academy of Sciences as the world’s leading authority on the regulation of salt and water metabolism and relevant endocrine control mechanisms. He is one of Australia’s most eminent scientists.
11-Deoxycortisol, also known as cortodoxone (INN), cortexolone as well as 17α,21-dihydroxyprogesterone or 17α,21-dihydroxypregn-4-ene-3,20-dione, is an endogenous glucocorticoid steroid hormone, and a metabolic intermediate towards cortisol. It was first described by Tadeusz Reichstein in 1938 as Substance S, thus has also been referred to as Reichstein's Substance S or Compound S.
The ACTH test is a medical test usually ordered and interpreted by endocrinologists to assess the functioning of the adrenal glands' stress response by measuring the adrenal response to adrenocorticotropic hormone or another corticotropic agent such as tetracosactide or alsactide (Synchrodyn). ACTH is a hormone produced in the anterior pituitary gland that stimulates the adrenal glands to release cortisol, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and aldosterone.
Frederic Crosby Bartter was an American endocrinologist best known for his work on hormones affecting the kidney and his discovery of syndrome of inappropriate antidiuretic hormone and Bartter syndrome. He had a separate interest in mushroom poisoning.
Sylvia Agnes Sophia Tait was an English biochemist and endocrinologist. She worked with her second husband, James Francis Tait, from 1948 until her death in 2003, a partnership described by the Oxford Dictionary of National Biography as "one of the most successful examples of husband-wife scientific collaboration". Together, they discovered and identified the hormone aldosterone, the last of a series of naturally occurring biologically potent steroid hormones to be isolated and identified between the 1920s to the 1950s, after the androgens, oestrogens, and glucocorticoid hormones. Aldosterone is part of the mechanism that regulates blood pressure, and causes conservation of sodium, secretion of potassium, increased water retention, and increased blood pressure. It is thought to be responsible for 15 per cent of cases of high blood pressure.
Maria Iandolo New is a professor of Pediatrics, Genomics and Genetics at Icahn School of Medicine at Mount Sinai in New York City. She is an expert in congenital adrenal hyperplasia (CAH), a genetic condition affecting the adrenal gland that can affect sexual development.
