Aldosterone analysis

OHF is almost exclusively excreted without undergoing -ring reduction and conjugation and can be measured in urine by HPLC-MS. A useful diagnostic ratio is that of 18-OHF UFF, which is normally about 5 1 and rises to 50 1 in GRA. Serum analysis is used to measure aldosterone (elevated in the disorder) and cortisol, but not typically for 18-OHF. 

In profile analysis, I shows low THAldo and 18-hydroxyTHA (the major 18-hydroxy corticosterone metabolite), but high excretions of THAs and THBs [26, 33]. In II, THAldo is low, the THAs and THBs normal, but 18-OH-THA is often grossly elevated. Representative excretions of several patients with both forms of the disorder are shown in Table 5.3.11. However, it must be emphasized that even if the steroid phenotype appears to have two forms, a single enzyme is responsible for aldosterone synthesis. 

Fredline VF, Taylor PJ, Dodds HM, Johnson AG (1997) A reference method for the analysis of aldosterone in blood by high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry. Anal Biochem 252 308-313... 

Honour JW, Dillon MJ, Shackleton CH (1982) Analysis of steroids in urine for differentiation of pseudohypoaldosteronism and aldosterone biosynthetic defect. J Clin Endocrinol Metab 54 325-331... 

Yoimg, D. B. (1988). Quantitative analysis of aldosterone s role in potassium regulation. 

APA-Dependent Hyperaldosteronism. The treatment of choice for APA-dependent aldosteronism remains laparoscopic resection of the adenoma. If no primary lesion is found, resection of one and a half of the adrenal glands may be attempted, followed by supplemental spironolactone therapy. However, a recent retrospective analysis of patients with aldosterone-producing adenomas who chose medical management instead of surgical resection, revealed medical management to be efficacious in this population and should be considered as an alternative in patients in whom surgery is contraindicated. ... 

The separation of endogenous 17- or 18-hydroxylated corticosteroids of the 21-hydroxylated 4-pregnen series was obtained by capillary electrophoresis of their charged borate chelate complexes (323). Aldosterone, 18-hydroxycorti-costerone, 18-hydroxy-deoxycorticosterone, cortisone, cortisol and 11-deoxycor-tisol are separated and resolved with 400 mM borate buffer at pH 9.0. The corticosteroid/borate chelation complex as indicated by CE data correlated well with 11 B-NMR. The separation of corticosteroids and benzothiazin analogs were studied by MEKC and a comparison with CZE was made (324). Bile salts, which have a similar carbon skeleton to the corticosteroids, were used for the separation of these steroids. A short analysis time, 15 min, and a high number of theoretical plates (150,000-350,000) were obtained. Sodium cholate was found to be very effective. The MEKC method was applied to the determination of the drug substance in tablets and cream formulations. An internal standard method was used for quantitation. The purity of the drug substance was also determined. 

The gas-phase analytical techniques have been used for the analysis of urinary steroids for a long time. The determinations of urinary estrogens, progesterone metabolites, 17-ketosteroids and, to a lesser degree, corticosteroid metabolites, with packed-column GC are extensively documented in the earlier monographs on the subject [274,290]. Various sample treatments, approaches to conjugate hydrolysis, and volatile derivatives have been described. Among those steroids, aldosterone stands out as a uniquely difficult substance to derivatize and determine. 

Aldosterone in the monohydra ted crystalline form is shown by X-ray analysis to have the 18-acetal-20-hemiacetal structure (l). The strain imposed upon ring... 

In short, polarography can be used for the analysis of C—N, C—O, N—O, O—O, S—S, and C—S groups and for the analysis of heterocyclic compounds. Also, many important biochemical species are electroactive, such as vitamin C (ascorbic acid), fumaric acid, vitamin B factors (riboflavin, thiamine, niacin), antioxidants such as tocopherols (vitamin E), A-nitrosamines, ketose sugars (fructose and sorbose), and the steroid aldosterone. 

The cyclic 20,21-boronates (38) provide an excellent means for qualitative g.c.-m.s. analysis of aldosterone, giving single g.c. peaks and abundant molecular ions. G.c.-m.s. study of 24i ,25-dihydroxycholecalciferol is conveniently carried out by forming the methylboronate or n-butylboronate of the side-chain diol system before silylating the 3/3-OH group. ... 

Sookoian S, Gianotti TF, Gonzalez CD, Pirola CJ (2007) Assoeiation of the C-344T aldosterone synthase gene variant with essential hypertension a meta-analysis. J Hypertens 25 5-13... 

Kiski D, Stepper W, Brand E, Breithardt G, Reinecke H. Impact of renin-angiotensin-aldosterone blockade by angiotensin-converting enzyme inhibitors or AT-1 blockers on frequency of contrast-induced nephropathy a post-hoc analysis from the Dialysis-versus-Diuresis (DVD) Trial. Nephrol Dial Transplant 2010 25 759-64. 

In patients with primary aldosteronism, the aldosterone levels in the blood and the amount of aldosterone excreted in the urine are markedly increased. Primary aldosteronism may or may not be associated with the development of a tumor of the adrenal cortex. When a tumor exists, it is usually small and weighs less than 6 g. Chemical analysis of the adrenal indicates that the cortex is rich in aldosterone, probably as a result of hypersecretion. Eighty-five per cent of the patients have a single or multiple adenoma of the adrenal cortex. Bilateral hyperplasia of the adrenals is found in 10% of the patients. 

Quantitative Analysis of Aldosterone and Cortisol from Blood by Gas Chromatography and Carbon-14 Tracers Atomlight 70 1-8 (1969) CA 71 120016x... 

Mitochondrial CYP11B2 (also known as CYPllp or steroid lip-hydroxylase) is involved in the synthesis of aldosterone. Aldosterone affects the conservation of sodium, the secretion of potassium, water retention, and blood pressure. CYPl 1B2 has been shown to catalyze the terminal regio- and stereospecific hydroxylation of deoxycorticosterone to aldosterone however, the exact mechanism of this process was not solved. Rapid-quenching experiments with the membrane-bound bovine CYP11B2 incorporated into liposome membranes have demonstrated that aldosterone is produced via corticosterone and not via 18-hydroxydeoxycorticosterone. Moreover, a kinetic analysis suggested a successive mechanism of aldosterone production from corticosterone, which did not dissociate from the binding site of the enzyme [34] (Scheme 5.5). 

Hu LJ, Chen YQ, Deng SB, Du JL, She Q. Additional use of an aldosterone antagonist in patients with mild to moderate chronic heart failure a systematic review and meta-analysis. Br J CHn Pharmacol 2013 75(5) 1202-12. 

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