Role of 21-deoxyaldosterone in human hypertension.

21-Deoxyaldosterone has been postulated to be a precursor of aldosterone in an alternative biosynthesis pathway and Kelly's-M1 is considered to be its metabolite. In healthy volunteers, the excretion rate of 21-deoxyaldosterone and of Kelly's-M1 are significantly lower than the aldosterone metabolites, aldosterone-18-glucuronide and tetrahydro-aldosterone and than the aldosterone precursor 18-OH-corticosterone. Essential hypertension patients (with low and normal renin) excrete comparable values of 21-deoxyaldosterone and Kelly's-M1 as normotensives. In 66% of aldosterone-producing adenoma cases (APA) and in 60% of idiopathic hyperaldosteronism (IHA) patients, significantly raised values of 21-deoxyaldosterone and Kelly's-M1 were found. The patients with the high excretion rates of both steroids showed only moderately increased values of the aldosterone metabolites, aldosterone-18-glucuronide and tetrahydro-aldosterone, as well as of the aldosterone precursor 18-OH-corticosterone. In contrast, the latter mentioned steroids were excreted in higher amounts in those patients with normal excretion of 21-deoxyaldosterone and Kelly's-M1. Hence, it is suggested that aldosterone is produced alternatively either via 18-OH-corticosterone alone or additionally via 21-deoxyaldosterone. Furthermore, in three cases of "incidentally" discovered adrenal adenomas, 21-deoxyaldosterone and Kelly's-M1 were the only elevated steroids. After adrenalectomy, excretion of 21-deoxyaldosterone and of Kelly's-M1 and blood pressure returned to normal, which proves that these steroids play a role in blood pressure regulation. In essential hypertension, ACTH infusion induced a significant increase of 21-deoxyaldosterone and Kelly's-M1. However, the increase after angiotensin II was 3- to 6-fold higher than after ACTH. IHA patients proved to be more responsive to angiotensin II; and, in contrast, APA cases proved to be more sensitive to ACTH. The data suggest that beside the main route of aldosterone biosynthesis via 11-deoxycorticosterone, corticosterone and 18-OH-corticosterone an alternative pathway exists via 21-deoxyaldosterone in healthy and in hypertensive patients. There are similarities between the regulation of 21-deoxyaldosterone and the regulation of aldosterone. The determination of 21-deoxyaldosterone and its possible metabolite Kelly's-M1 might be appropriate in the diagnosis of mineralocorticoid-induced forms of hypertension, especially when an adrenal adenoma is discovered.

Urinary 18,19-dihydroxycorticosterone and 18-hydroxy-19-norcorticosterone excretion in patients with primary and secondary aldosteronism.

18,19-Dihydroxycorticosterone (18,19(OH)2-B) and 18-hydroxy-19-norcorticosterone (18-OH-19-nor-B) measurements were carried out on the urine of patients with primary aldosteronism (PA), essential hypertension (EHT), and liver cirrhosis with (LC, SA (+)) and without (LC, SA (-)) aldosteronism. The separation of these steroids was performed by extraction and high-performance liquid chromatography followed by radioimmunoassay (RIA) with specific antibodies prepared in our laboratory. 18,19(OH)2-B excretion was elevated in patients with PA (24 +/- 5.9 [+/- SE] micrograms/24 hr; n = 15) and LC, SA (+) (83 +/- 9.4 micrograms/24 hr; n = 8). Values in LC, SA (-) (3.1 +/- 1.2 micrograms/24 hr; n = 8) and in EHT (3.7 +/- 0.4 micrograms/24 hr; n = 42) were found to be similar to those in normal subjects (5.5 +/- 0.9 micrograms/24 hr; n = 30). The values of urinary 18-OH-19-nor-B in PA and LC, SA (+) were higher than in LC, SA (-) EHT and normal subjects (P less than 0.05). Values in the latter three groups, as compared with each other, did not show significant alterations. Nothing is known about the biologic relevance of 18,19(OH)2-B and very little about that of 18-OH-19-nor-B, but the latter steroid seems to potentiate experimental renal hypertension. One can speculate about possible roles of both steroids as precursors of other steroids, e.g., the biologically potent mineralocorticoid 19-noraldosterone. The data obtained suggest that it is not relevant to measure the urinary levels of either steroid in these clinical syndromes.

Synthesis of 19-nor-aldosterone, 18-hydroxy-19-nor-corticosterone and 18,19-dihydroxycorticosterone in the human aldosterone-producing adenoma.

The recently synthesized 18-C-steroid derivative, 19-nor-aldosterone(19-nor- aldo) and 18-hydroxy-19-nor-corticosterone(18-OH-19-nor-corticosterone) possess mineralocoroticoid and hypertensinogenic activity. They and an additional newly synthesized steriod, 18,19-dihydroxycorticosterone[18,19(OH)2-corticosterone], may play a role in the etiology and pathogenesis of disorders thought to be caused by steroids with mineralocorticoid and hypertensionogenic properties. In this study we provide evidence that 19-nor-aldo, 18-OH-19-nor-corticosterone and 18,19(OH)2-corticosterone are produced in vitro by aldosterone-producing adrenal adenomas and adenomas and adenoma of Cushing's syndrome. "silent" adrenal adenomas and the adjacent adrenal tissue. Measurable amounts of these steroids were found in the incubation fluids of adrenal tissues using specific RIAs performed after a sequence of HPLC systems. The rates of production of the three steroids were high in the aldosterone-producing adrenal adenomas and in adrenal hyperplasia compared with in either Cushing's adenoma or "silent" adenoma.

Production of 21-deoxyaldosterone by rat adrenal tissue in vitro: evidence for an alternative biosynthetic pathway of aldosterone.

Quartered rat adrenal glands transformed labelled 21-deoxyaldosterone into aldosterone in vitro. 21-deoxyaldosterone was released from the quartered rat adrenals in vitro in amounts 10 times lower than those of aldosterone and 18-hydroxycorticosterone. The production of all three steroids was qualitatively dependent on the same regulatory elements (electrolytes, ACTH, exogenous precursors, zonal specificity). However, quantitative differences could be observed. The results support a role for 21-deoxyaldosterone as a facultative precursor of aldosterone and indicate that the regulation of its production shows similarities to that of aldosterone.

Urinary excretion of aldosterone metabolite Kelly-M1 in patients with adrenal dysfunction.

Using tetrahydroaldosterone antibody a radioimmunoassay was developed to measure substance Kelly-M1 (K-M1) in human urine. The normal values were lower than observed by Kelly et al. who discovered the catabolite after giving large doses of exogenous aldosterone. While in essential hypertension the excretion of K-M1 was predominantly within the normal range, elevated values were found in most cases of 21-hydroxylase deficiency, both the simple virilizing and salt losing form, primary aldosteronism, renal hypertension and cystinosis. Our findings suggest that K-M1 may be formed from 21-deoxyaldosterone and/or by microbial intervention from aldosterone or its metabolites.

21-Deoxyaldosterone excretion in patients with primary aldosteronism and 21-hydroxylase deficiency.

21-Deoxyaldosterone appears in urine in free and conjugated forms. Total excretion is best determined after acid hydrolysis (pH 1) of urine, followed by extraction, repeated chromatographic purification, and quantitation of the steroid by RIA. 21-Deoxyaldosterone excretion was normal in 70% of patients with essential hypertension (n = 18), while 30% (n = 8) had more or less elevated values. In patients with primary aldosteronism (n = 21) elevated as well as normal values of urinary 21-deoxyaldosterone were found, indicating that in some patients aldosterone may be formed not only from corticosterone but also from the 21-deoxy compound. In patients with 21-hydroxylase deficiency (n = 21) urinary 21-deoxyaldosterone was invariably elevated, whether the patients had the virilizing or salt-losing form of the disease. Although the clinical manifestations of the salt-losing form seem unrelated to the inability to convert 21-deoxyaldosterone to aldosterone, the determination of 21-deoxyaldosterone adds insight into the biosynthesis of aldosterone in primary aldosteronism and 21-hydroxylase deficiency.