aldosterone

(redirected from Aldosterone antagonist)
Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Wikipedia.
Related to Aldosterone antagonist: potassium sparing diuretics

aldosterone

(ăl'dōstĭrōn`), steroid secreted by the cortex of the adrenal gland. It is the most potent hormonehormone,
secretory substance carried from one gland or organ of the body via the bloodstream to more or less specific tissues, where it exerts some influence upon the metabolism of the target tissue.
..... Click the link for more information.
 regulating the body's electrolyte balance. Aldosterone acts directly on the kidney to decrease the rate of sodium-ion excretion (with accompanying retention of water), and to increase the rate of potassium-ion excretion. The secretion of aldosterone appears to be regulated by two mechanisms. First, the concentration of sodium ions may be a factor since increased rates of aldosterone secretion are found when dietary sodium is severely limited. Second, reduced blood flow to the kidney stimulates certain kidney cells to secrete the proteolytic enzyme renin, which converts the inactive angiotensinogen globulin in the blood into angiotensin I. Another enzyme then converts angiotensin I into angiotensin II, its active form. This peptide, in turn, stimulates the secretion of aldosterone by the adrenal cortex. Pathologically elevated aldosterone secretion with concomitant excessive retention of salt and water often results in edema.

Aldosterone

The steroid hormone found in the biologically active amorphous fraction that remains after separation of the various crystalline steroid substances, such as cortisol and corticosterone, from adrenal extracts. In solution, aldosterone exists as an equilibrium mixture of aldo and lactol forms (see illustration).

Structures for two forms of aldosterone in an equilibrium mixture, ( a ) aldo and ( b ) lactolenlarge picture
Structures for two forms of aldosterone in an equilibrium mixture, (a) aldo and (b) lactol

The chief function of aldosterone is the regulation of electrolyte metabolism, that is, promotion of sodium retention and enhancement of potassium excretion. Aldosterone is the most potent of the hormones which are concerned in this type of metabolism. See Adrenal gland, Hormone, Steroid

Aldosterone

 

(also electrocortin, or aldocortin), an adrenocortical hormone of the group of corticosteroids. It regulates mineral metabolism in the organism and is the basic mineralocorticoid. The molecular mass is 360.43.

Aldosterone was isolated in a crystalline form in 1953 and synthesized in 1959 by Wettstein. It helps to retain sodium ions (Na+) in the organism and to eliminate potassium ions (K+) in the urine, saliva, and perspiration. A deficiency of Na+ and an elevated K+ content in food lead to an increase in the formation of aldosterone. An insufficiency of aldosterone—for example, with adrenalectomy or with Addison’s disease—leading to an acute loss of Na, imperils the life of the organism. The increased formation of aldosterone—for example, with adrenal tumors and certain heart and kidney diseases—causes the retention of water in the organism (edema), an increase in blood pressure, and so forth. The level of aldosterone secretion is related to the relative Na+ and K+ content in the blood plasma and is regulated by the mesencephalon, which secretes the neurohormone adrenoglomerulotropine with the participation of angiotensin and renin, which is formed in the kidneys and the vegetative nervous system.

REFERENCE

Berzin, T. Biokhimiia gormonov. Moscow, 1964. Page 259. (Translated from the German.)

G. L. SHREIBERG

aldosterone

[al′däs·tə‚rōn]
(biochemistry)
C21H28O5 A steroid hormone extracted from the adrenal cortex that functions chiefly in regulating sodium and potassium metabolism.
References in periodicals archive ?
The average serum potassium level in patients treated with an aldosterone antagonist was 4.
Similar benefits have been shown for angiotensin receptor blockers14, and aldosterone antagonists (AA)15-16.
Aldosterone antagonists confer additional mortality benefit but require close monitoring for the development of severe hyperkalemia and renal dysfunction.
In one report, aldosterone antagonists failed to improve mortality or reduce CV readmissions in patients who had heart failure with decreased ejection fraction, after clinical trials had indicated the agents would do so.
Boxer noted that serum aldosterone level in patients with heart failure predicts mortality Aldosterone blockade with an aldosterone antagonist has been shown to improve clinical outcomes in heart failure patients with a depressed left ventricular ejection fraction in RALES, the Randomized Aldactone Evaluation Study (N.
This study wasn't designed to determine why the results contradicted the "impressive benefits of aldosterone antagonist therapy" reported in "pivotal" efficacy trials as well as in a systematic review of randomized clinical trials of the therapy.
The best multidrug combinations for isolated systolic hypertension include diuretics; ACE inhibitors or angiotensin receptor blockers; dihydropyridine calcium channel blockers; and an aldosterone antagonist, he said.
PARIS -- The aldosterone antagonist eplerenone cut cardiovascular events and the need for hospitalization significantly across all risk levels in patients with mild heart failure, according to a subanalysis of EMPHASIS-HF trial data.
Specifically, CRT and ICD use increased by 30 and 27 percent, respectively, and aldosterone antagonist use increased by 25 percent, all compared to baseline results.
The criteria included completion of a heart failure education course, and daffy treatment with an evidence-based dosage of an ACE inhibitor or angiotensin II receptor blocker (ARB), beta-blocker, and, when appropriate, an aldosterone antagonist.
The open-label study of heart failure patients with chronic kidney disease is intended to explore dosing of RLY5016 and an aldosterone antagonist with the aim of maintaining serum potassium levels in the normal range.
Baseline background treatment included beta-blockers (92%), an ACE inhibitor/angiotensin-receptor blocker (96%), or an aldosterone antagonist (72%).