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Pseudohyperaldosteronism
Pseudohyperaldosteronism (also pseudoaldosteronism) is a medical condition which mimics the effects of elevated aldosterone (hyperaldosteronism) by presenting with high blood pressure, low blood potassium levels (hypokalemia), metabolic alkalosis, and low levels of plasma renin activity (PRA). However, unlike hyperaldosteronism, this conditions exhibits low or normal levels of aldosterone in the blood. Causes include genetic disorders (e.g. apparent mineralocorticoid excess syndrome, Liddle's syndrome, and types of congenital adrenal hyperplasia), acquired conditions (e.g. Cushing's syndrome and mineralocorticoid-producing adrenal tumors), metabolic disorders, and dietary imbalances including excessive consumption of licorice. Confirmatory diagnosis depends on the specific cause and may involve blood tests, urine tests, or genetic testing; however, all forms of this condition exhibit abnormally low concentrations of both plasma renin activity (PRA) and plasma aldosterone concentra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Mineralocorticoid Excess Syndrome
Apparent mineralocorticoid excess syndrome (AME) is an autosomal recessive disorder causing hypertension (high blood pressure), hypernatremia (increased blood sodium concentration) and hypokalemia (decreased blood potassium concentration). It results from mutations in the '' HSD11B2'' gene, which encodes the kidney isozyme of 11β-hydroxysteroid dehydrogenase type 2. In an unaffected individual, this isozyme inactivates circulating cortisol to the less active metabolite cortisone. Liquorice consumption can also inhibit the enzyme and cause AME. The inactivating mutation leads to elevated local concentrations of cortisol in the aldosterone sensitive tissues like the kidney. Cortisol at high concentrations can cross-react and activate the mineralocorticoid receptor due to the non-selectivity of the receptor, leading to aldosterone-like effects in the kidney. This is what causes the hypokalemia, hypertension, and hypernatremia associated with the syndrome. Patients often present wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperaldosteronism
Hyperaldosteronism is a medical condition wherein too much aldosterone is produced. High aldosterone levels can lead to lowered levels of potassium in the blood (hypokalemia) and increased hydrogen ion excretion (alkalosis). Aldosterone is normally produced in the adrenal glands. Primary aldosteronism is when the adrenal glands are too active and produce excess amounts of aldosterone. Secondary aldosteronism is when another abnormality causes the excess production of aldosterone. Signs and symptoms Hyperaldosteronism can be asymptomatic, but these symptoms may be present: * Fatigue * Headache * High blood pressure * Hypokalemia * Hypernatraemia * Hypomagnesemia * Intermittent or temporary paralysis * Muscle spasms * Muscle weakness * Numbness * Polyuria * Polydipsia * Tingling * Metabolic alkalosis Causes Primary Primary aldosteronism (hyporeninemic hyperaldosteronism) is most often caused by bilateral idiopathic (micronodular) adrenal hyperplasia (almost 70% of cases) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Mineralocorticoid Excess
Apparent mineralocorticoid excess syndrome (AME) is an autosome, autosomal dominance (genetics), recessive disorder causing hypertension (high blood pressure), hypernatremia (increased blood sodium concentration) and hypokalemia (decreased blood potassium concentration). It results from mutations in the ''HSD11B2'' gene, which encodes the kidney isozyme of 11β-Hydroxysteroid dehydrogenase type 2, 11β-hydroxysteroid dehydrogenase type 2. In an unaffected individual, this isozyme inactivates circulating cortisol to the less active metabolite cortisone. Liquorice (confectionery), Liquorice consumption can also inhibit the enzyme and cause AME. The inactivating mutation leads to elevated local concentrations of cortisol in the aldosterone sensitive tissues like the kidney. Cortisol at high concentrations can cross-react and activate the mineralocorticoid receptor due to the non-selectivity of the receptor, leading to aldosterone-like effects in the kidney. This is what causes the hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Hypertension
Secondary hypertension (or, less commonly, inessential hypertension) is a type of hypertension which has a specific and identifiable underlying primary cause. It is much less common than essential hypertension, affecting only 5-10% of hypertensive patients. It has many different causes including obstructive sleep apnea, kidney disease, endocrine diseases, and tumors. The cause of secondary hypertension varies significantly with age. It also can be a side effect of many medications. Common causes and prevalence The cause of secondary hypertension are numerous (obstructive sleep apnea, kidney disease, endocrine diseases, tumors, medication side effect, Etc.) and etiologies varies significantly with age. Obstructive sleep apnea Obstructive sleep apnea (OSA) is one of the most common causes; 30-50% of patients who have OSA have co-morbid secondary hypertension. OSA is prevalent in older adults and should be considered in cases of resistant hypertension, hypertension refractory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liddle's Syndrome
Liddle's syndrome, also called Liddle syndrome, is a genetic disorder inherited in an autosomal dominant manner that is characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule, and is treated with a combination of low sodium diet and potassium-sparing diuretics (e.g. amiloride). It is extremely rare, with fewer than 30 pedigrees or isolated cases having been reported worldwide as of 2008. Signs and symptoms Children with Liddle syndrome are frequently asymptomatic. The first indication of the syndrome often is the incidental finding of hypertension during a routine physical exam. Because this syndrome is rare, it may only be considered by the treating physician after the child's hypertension does not respond to m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cortisone
Cortisone is a pregnene (21-carbon) steroid hormone. It is a naturally-occurring corticosteroid metabolite that is also used as a pharmaceutical prodrug. Cortisol is converted by the action of the enzyme corticosteroid 11-beta-dehydrogenase isozyme 2 into the inactive metabolite cortisone, particularly in the kidneys. This is done by oxidizing the alcohol group at carbon 11 (in the six-membered ring fused to the five-membered ring). Cortisone is converted back to the active steroid cortisol by stereospecific hydrogenation at carbon 11 by the enzyme 11β-Hydroxysteroid dehydrogenase type 1, particularly in the liver. The term "cortisone" is frequently misused to mean either any corticosteroid or hydrocortisone, which is in fact cortisol. Many who speak of receiving a "cortisone shot" or taking "cortisone" are more likely receiving hydrocortisone or one of many other, much more potent synthetic corticosteroids. Cortisone can be administered as a prodrug, meaning it has to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithelial Sodium Channel
The epithelial sodium channel (ENaC), (also known as amiloride-sensitive sodium channel) is a membrane-bound ion channel that is selectively permeable to sodium ions (). It is assembled as a heterotrimer composed of three homologous subunits α or δ, β, and γ, These subunits are encoded by four genes: '' SCNN1A'', ''SCNN1B'', '' SCNN1G'', and '' SCNN1D''. The ENaC is involved primarily in the reabsorption of sodium ions at the collecting ducts of the kidney's nephrons. In addition to being implicated in diseases where fluid balance across epithelial membranes is perturbed, including pulmonary edema, cystic fibrosis, COPD and COVID-19, proteolyzed forms of ENaC function as the human salt taste receptor. The apical membranes of many tight epithelia contain sodium channels that are characterized primarily by their high affinity for the diuretic blocker amiloride. These channels mediate the first step of active sodium reabsorption essential for the maintenance of body salt and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having Heterozygosity, two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or Heredity, inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticosteroid 11-beta-dehydrogenase Isozyme 2
Corticosteroid 11-β-dehydrogenase isozyme 2 also known as 11-β-hydroxysteroid dehydrogenase 2 is an enzyme that in humans is encoded by the gene. Function Corticosteroid 11-β-dehydrogenase isozyme 2 is an NAD+-dependent enzyme expressed in aldosterone-selective epithelial tissues such as the kidney, colon, salivary and sweat glands. HSD211B2 expression is also found in the brainstem in a small, aldosterone-sensitive subset of neurons located in the nucleus of the solitary tract referred to as HSD2 neurons. In these tissues, HSD11B2 oxidizes the glucocorticoid cortisol to the inactive metabolite cortisone, thus preventing illicit activation of the mineralocorticoid receptor. This protective mechanism is necessary because cortisol circulates at 100- to 1000-fold higher concentrations than aldosterone, and binds with equal affinity to the mineralocorticoid receptor, thereby out-competing aldosterone in cells that do not produce HSD11B2. This glucocorticoid-inactivating enzyme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticosterone
Corticosterone, also known as 17-deoxycortisol and 11β,21-dihydroxyprogesterone, is a 21-carbon steroid hormone of the corticosteroid type produced in the cortex of the adrenal glands. In the very rare case of congenital adrenal hyperplasia due to 17α-hydroxylase deficiency cortisol production is blocked. Roles In many species, including amphibians, reptiles, rodents and birds, corticosterone is a main glucocorticoid, involved in regulation of energy, immune reactions, and stress responses. However, in humans, cortisol is the primary glucocorticoid that is produced primarily in the zona fasciculata of the adrenal cortex. Corticosterone has only weak glucocorticoid and mineralocorticoid potencies in humans and is important mainly as an intermediate in the steroidogenic pathway from pregnenolone to aldosterone. Corticosterone is converted to aldosterone by aldosterone synthase, found only in the mitochondria of glomerulosa cells. Glomerulosa cells are found in the zon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital Adrenal Hyperplasia Due To 11β-hydroxylase Deficiency
Congenital adrenal hyperplasia due to 11β-hydroxylase deficiency is a form of congenital adrenal hyperplasia (CAH) which produces a higher than normal amount of androgen, resulting from a defect in the gene encoding the enzyme steroid 11β-hydroxylase (11β-OH) which mediates the final step of cortisol synthesis in the adrenal. 11β-OH CAH results in hypertension due to excessive mineralocorticoid effects. It also causes excessive androgen production both before and after birth and can virilize a genetically female fetus or a child of either sex. Presentation Mineralocorticoid effects Mineralocorticoid manifestations of severe 11β-hydroxylase deficient CAH can be biphasic, changing from deficiency (salt-wasting) in early infancy to excess (hypertension) in childhood and adult life. Salt-wasting in early infancy does not occur in most cases of 11β-OH CAH but can occur because of impaired production of aldosterone aggravated by the inefficiency of salt conservation in early in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
