產(chǎn)品名稱：Aldosterone ELISA 產(chǎn) 地：Demeditec 產(chǎn)品貨號：DE4128 產(chǎn)品規(guī)格：96 Tests 產(chǎn)品說明： Special remarks: Aldosterone produced in the adrenal cortex, is the most potent mineralcorticoid in humans. As with other steroid hormones, aldosterone is synthesized from cholesterol through a series of enzyme-mediated steps. Aldosterone and cortisol differ only in that a hydroxyl modification occurs at the 18, rather than 17, position on the steroid molecule. The first and rate-limiting step in steroidogenesis, conversion of cholesterol to pregnenolone, is stimulated by adrenocorticotropic hormone (ACTH). However, ACTH has only a minimal effect on aldosterone production. Aldosterone secretion appears to be stimulated primarily through the renin-angiotensin system: decreased plasma volume and renal perfusion (or decreased plasma sodium chloride concentration) leads renin secretion and activation of angiotensin, with angiotensin II then stimulating aldosterone synthesis. Increased plasma potassium concentrations are also a strong independent stimulus for aldosterone production, although this effect is partially countered by potassium inhibition of renin release. The major defined action of aldosterone is stimulation of renal tubular sodium and chloride reabsorption, primarily at the level of the collecting ducts. Other important renal actions include enhancement of urinary potassium and hydrogen (acid) excretion. Similar effects on transmembrane sodium and hydrogen transport have been observed in other tissues, including lymphocytes, brain and arterial smooth muscle. Plasma aldosterone levels normally vary with body position (upright>supine) and salt intake. Overall plasma aldosterone levels show a circadian rhythm which is similar but less marked than cortisol, with peak levels in the early morning. Age-related levels tend to decline from fetal through ***** life. Aldosterone concentrations in urine and saliva have also been characterized. Abnormally high plasma aldosertone concentrations can occur as either primary (e.g. in primary adenomas, glucocorticoid-responsive hypersaldosteroism, idiopathic) or secondary conditions. In primary hyperaldosteronism, renin levels are low, blood pressure is elevated and the potassium level is decreased. Secondary hyperaldosteronism occurs as a result of elevated renin secretion, and is observed in renovascular hypertension, renin-secreting tumors, intravascular volume depletion (dehydration), hypoadremia, and in Barther’s syndrome. High aldosterone and renin levels are also observed in pseudohypoaldosteronism, a condition caused by end-organ unresponsiveness to aldosterone leading to clinical features of aldosterone deficiencies. Abnormally low aldosterone secretion occurs in a number of conditions including salt-wasting forms congenital adrenal hyperplasia, isolated 13-hydroxylase (carboxymethyl oxidase type deficiency, renin deficiency (e.g. nephropathy), and type 4 renal tubular acidosis. Low aldosterone concentrations in the presence of clinical features of hyperaldosteronism can be observed in 11-hydroxylase (P450c11) deficiency, 11beta-hydroxysteroid dehydrogenase deficiency, and after ingestion of materials containing mineralocorticoid-like substances (e.g. licorice glycyntizic acid). 上海玉博生物技術(shù)有限公司在為生命科學(xué)領(lǐng)域提供豐富的產(chǎn)品與信息資源方面處于國內(nèi)**地位，公司提供的產(chǎn)品涵蓋了二十多個(gè)國家近五十萬種產(chǎn)品，而且產(chǎn)品的數(shù)量與信息在不斷的增長和更新，公司提供的產(chǎn)品能夠使生命科學(xué)工作者加快對生物化學(xué)，分子生物學(xué)，細(xì)胞生物學(xué)以及蛋白質(zhì)組學(xué)研究的認(rèn)知，以及分子診斷和臨床醫(yī)學(xué)領(lǐng)域的應(yīng)用。
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