19-nor-deoxycorticosterone excretion in rats bred for susceptibility and resistance to the hypertensive effects of salt.

Rats susceptible (S/JR) and resistance (R/JR) to the hypertensive effect of salt were weaned at 28 days of age and placed on a high salt intake. Blood pressure, measured at 4-5 and 8-9 weeks of age (after 5 weeks of high salt intake), demonstrated a slight increase in R/JR rats and a highly significant increase in S/JR rats. Urinary fee 19-nor-deoxycorticosterone (19-nor-DOC) levels measured in weekly urine collections were found to be markedly elevated in S/JR rats compared to levels in R/JR rats. Since 19-nor-DOC has been shown to be a potent mineralocorticoid, the results suggest that elevated production of 19-nor-DOC may have a role in hypertension in rats susceptible to the hypertensive effects of salt.

19-Nor-deoxycorticosterone metabolism by rat adrenal glands: evidence for the formation of 19-nor-corticosterone and 19-nor-18-hydroxydeoxycorticosterone.

Incubation of rat adrenal homogenates with tritiated and unlabeled 19-nor-deoxycorticosterone yielded, in addition to unconverted starting substrate, two major radioactive conversion products. These two products were purified by TLC and HPLC and subjected to mass spectrometry and nuclear magnetic resonance analysis. The interpretation of the spectra was consistent with the structures to be 19-nor-corticosterone and 19-nor-18-hydroxydeoxycorticosterone. The possible biological significance of these two compounds is discussed.

Relationship of 19-nor-deoxycorticosterone to other mineralocorticoids in low-renin hypertension.

A number of mineralocorticoids have been proposed as etiologic factors in low-renin hypertension. In this study, urinary free 19-nor-deoxycorticosterone (UF 19-nor-DOC) was compared to other mineralocorticoids--aldosterone, deoxycorticosterone (DOC), and 18-OH-DOC, in 11 low-renin hypertensive patients on a controlled diet in a metabolic unit. Results demonstrated that both UF 19-nor-DOC and tetrahydro-DOC (TH-DOC) excretion were elevated (2086 +/- 926, nl = 339-579 ng/day, and 18 +/- 7, nl = 5-15 mcg/day, respectively), and positively correlated (r = 0.95). Neither 18-OH-DOC nor aldosterone secretion rates were elevated, and neither of these hormones correlated with UF 19-nor-DOC, with exception of the supine plasma aldosterone (SPA) (r = 0.86). In conclusion, both UF 19-nor-DOC and TH-DOC were increased and positively correlated in the present series of hypertensives. This association is possibly indicative of a precursor-product relationship between DOC and 19-nor-DOC. 19-Nor-DOC, furthermore, correlated with supine plasma aldosterone (SPA), which could, in part, reflect their shared adrenocorticotropic hormone (ACTH) dependence.

19-nor-deoxycorticosterone excretion in primary aldosteronism and low renin hypertension.

Nonaldosterone mineralocorticoids, such as deoxycorticosterone (DOC) and 18-hydroxy-DOC, have been reported to be elevated in some patients with primary aldosteronism (PA). Since DOC is a probable precursor of a more potent mineralocorticoid, 19-nor-deoxycorticosterone (19-nor-DOC), this study evaluated urinary free (UF) 19-nor-DOC excretion in 6 patients with PA and compared the results to those from 11 patients with low renin hypertension (LRH) and 7 normotensive subjects. PA was due to either an aldosterone-producing adenoma (APA; 4 patients) or bilateral adrenal hyperplasia (2 patients) diagnosed by adrenal venous catheterization or surgery. Compared to LRH subjects, patients with PA had a higher mean blood pressure (137 +/- 9 vs. 114 +/- 3 mm Hg), a lower plasma potassium level (3.1 +/- 0.2 vs. 3.9 +/- 0.1 meq/1) and greater renin suppression (0.3 +/- 0.1 vs. 0.6 +/- 0.1 ng angiotensin I/ml . h). UF 19-nor-DOC levels were elevated in PA subjects compared to those in normotensives (3,716 +/- 1,517 vs. 428 +/- 112 ng/day) but not compared to those in LRH patients (1,237 +/- 471). Two patients with APA had distinctly elevated UF 19-nor-DOC levels (11,137 and 7,744 ng/day), but another APA patient had the lowest value (305 ng/day). UF 19-nor-DOC positively correlated with the aldosterone secretion rate in PA (r = 0.75) but not LRH subjects. In conclusion, this study demonstrates that patients with PA may have elevated levels of UF 19-nor-DOC which are proportional to the aldosterone excess and could be a contributing factor to the hypertension, hypokalamia, and excess mineralocorticoid activity of this disease.

The regulation of urinary free 19-nor-deoxycorticosterone and its relation to systemic arterial blood pressure in normotensive and hypertensive subjects.

19-Nor-deoxycorticosterone (19-nor-DOC) is a naturally occurring, potent mineralocorticoid present in hypertensive animal models as well as man. To investigate 19-nor-DOC's regulation and possible pathogenesis in hypertension, urinary free (UF) 19-nor-DOC was measured in 14 hypertensives, correlated with other corticosteroids and systemic arterial blood pressure (BP), and compared to basal and ACTH-stimulated values in 8 normotensive subjects. Seven of the 14 hypertensives had low-renin hypertension, 2 had primary aldosteronism, 1 had an adrenal carcinoma, and another had acromegaly. These studies determined that: 1) although the mean UF 19-nor-DOC was not increased in hypertensives (588 +/- 180 vs. 428 +/- 122 ng/day), 2 low-renin hypertensives had quite elevated levels (2186 and 2018); 2) the UF 19-nor-DOC in hypertensives was correlated with BP but not with PRA, aldosterone secretion, plasma potassium, basal plasma cortisol, or 17-hydroxycorticosteroids; 3) likewise, in normotensives, UF 19-nor-DOC did not correlate with basal plasma cortisol, cortisol secretion, or 17-hydroxycorticosteroids excretion but did correlate after ACTH stimulation. Therefore, although 19-nor-DOC is activated by ACTH administration, it is not correlated with basal parameters of cortisol production, suggesting that factors other than ACTH regulate basal 19-nor-DOC secretion. Furthermore 19-nor-DOC is elevated in some hypertensive patients, and it is directly related to the elevation of mean systemic BP. This suggests that, although 19-nor-DOC could contribute to hypertensive disease in some individuals, it does not appear to be due to excess ACTH.

Plasma and urinary 19-nor-deoxycorticosterone in 17 alpha-hydroxylase deficiency syndrome.

17 alpha-hydroxylase deficiency syndrome (17-OHDS) is associated with hypogonadism, hypertension, and hypokalemia. Aldosterone production, however, is not elevated, and therefore, other known or unknown mineralocorticoids must account for the excess in mineralocorticoid activity. This study sought to determine whether 19-nor-deoxycorticosterone (19-nor-DOC), a potent hypertensinogenic mineralocorticoid, was elevated in this syndrome. Plasma and urine from a young woman with 17-OHDS were examined from various corticosteroids before and after ACTH, dexamethasone, and cortisol administration. In the basal state, urinary and plasma 17-hydroxycorticosteroids were decreased, but 17-deoxycorticosteroids were extremely elevated, including corticosterone (B), 18-hydroxy-B (18-OH-B), tetrahydro-B (TH-B), TH-DOC, and 18-OH-TH-DOC. Basal urinary (UF) 19-nor-DOC measured by both high pressure liquid chromatography (4255 ng/day) and RIA [3800 ng/day; normal, 102 +/- 27 (+/- SD), was markedly elevated. UF 19-nor-DOC did not increase further after ACTH administration (4255 ng/day), but it decreased after both dexamethasone (less than 100 ng/day) and cortisol therapy (612 and 218 ng/day). Basal plasma 19-nor-DOC was elevated and increased after ACTH stimulation (366 pg/ml) and decreased during dexamethasone suppression (6 pg/ml). A plasma 19-nor-DOC precursor that converted to nor-DOC upon acidification (perhaps 19-oic-DOC) also was detectable (172 pg/ml). This study, therefore, demonstrates a marked elevation in UF 19-nor-DOC in 17-OHDS, which could account for some of the excess mineralocorticoid activity in this syndrome.

19-nor-DOC biosynthesis in the isolated perfused rat kidney.

19-nor-deoxycorticosterone (19-nor-DOC) is a potent salt retaining and hypertensinogenic mineralocorticoid that is excreted in the urine. While the precursor of 19-nor-DOC, 19-oxo-DOC, is produced by the adrenal cortex, conversion to 19-nor-DOC does not occur in the adrenal gland. We have examined the hypothesis that 19-nor-DOC is synthesized from precursors in the kidney. 19-oxo-DOC was added to the perfusate of isolated rat kidney preparations (n = 5) at a concentration of 10 microM. During 1 h of perfusion following addition of 19-oxo-DOC, 71 +/- 6% of the precursor was converted to 19-oic-DOC, an immediate precursor of 19-nor-DOC, and 8.3 +/- 1.8% was converted to 19-nor-DOC. This represents the first definitive evidence that 19-nor-DOC is produced in the kidney from adrenal precursors.

Identification of 19-hydroxydeoxycorticosterone in regenerating rat adrenal incubations.

19-Hydroxydeoxycorticosterone (19-OH-DOC) was isolated from the incubation medium of enucleated rat adrenal glands during the early sodium retaining phase. Identification included comparison of chromatographic mobility of parent and derivatized compound with standard prepared by the 21-hydroxylation of 19-hydroxyprogesterone and mass spectrometry. The possible role of 19-OH-DOC as a precursor is discussed.

19-Nor-deoxycorticosterone in the neutral fraction of human urine.

19-Nor-deoxycorticosterone (19-nor-DOC), in the neutral fraction of human urine, was isolated and quantitated as the acetate derivative using ultraviolet absorption of the peak emerging from a high-pressure liquid chromatographic column. Identification of 19-nor-DOC in a pooled collection of urine after ACTH administration included identical chromatographic mobilities as the parent compound and acetate derivative compared to authentic 19-nor-DOC and mass spectral analysis of the acetate derivative. Values obtained for control and post-ACTH urines were 528 +/- 100 (SE) ng/24 hours and 8851 +/- 824 ng/24 hours, respectively. One patient with primary aldosteronism excreted 1894 ng/24 hours.

Effect of 4-hydroxyandrostenedione on 19-hydroxylation of deoxycorticosterone in the golden Syrian hamster.

4-Hydroxyandrostenedione, a known inhibitor of ovarian and peripheral aromatization of androgen (testosterone and androstenedione) to form estrogen, was studied for its inhibitory effect on the 19-hydroxylating enzyme system of the adrenal for the conversion of deoxycorticosterone to 19-hydroxydeoxycorticosterone. In vitro incubation of Golden Syrian hamster adrenal homogenates with tritiated deoxycorticosterone demonstrated (80-85%) reduction in label incorporated into 19-hydroxydeoxycorticosterone in the presence of 4-hydroxyandrostenedione.

Identification of 19-nor-corticosterone in rat urine.

19-Nor-corticosterone (19-nor-B) was isolated from a pool of urine collected from Wistar-Kyoto (WKY) rats. Identity was established by comparison of chromatographic mobilities with standard 19-nor-B both as the free compound and diacetate derivative. Comparison of the gas chromatographic-mass spectra of the urinary product and standard 19-nor-B as the diacetate following isolation by high pressure liquid chromatography (HPLC) confirmed the identity of the urinary product to be 19-nor-B. This demonstration that 19-nor-B is a naturally occurring product in addition to 19-nor-deoxycorticosterone supports the concept of the existence of a biosynthetic pathway for the formation of the 19-nor-corticosteroids.

Synthesis of 18-hydroxy-19-norcorticosterone and 18-deoxy-19-noraldosterone. Structure determination of related 19-nor steroids by means of 2-D 1H nmr.

The compounds named in the title have been synthesized from the di-(ethylene ketal) of 21-hydroxy-3,20-dioxo-19-norpregn-5-ene-18, 11 beta-lactone and its 5(10)-ene isomer. Reduction of this mixture 1 with sodium aluminum bis-(methoxyethoxy)hydride furnished the 11 beta, 18, 21-triol 2a. Conversion to the 18,21-diacetate 2b, followed by deketalization to the free dione 3 and hydrolysis, afforded 18-hydroxy-19-norcorticosterone 4a which, in the solid state and probably in solution, has the 18,20-hemiacetal structure. Periodate oxidation of 4a gave 11 beta-hydroxy-3-oxo-19-norandrost-4-ene-17 beta, 18-carbolactone 5a, and acid treatment of 4a or its precursor 2a yielded 18-deoxy-19-noraldosterone 6a. The structure of 5a was confirmed by mass spectrometry and 1H nmr, and compared with that of its C-19 methyl homolog 5b and 19-noraldosterone-gamma-etiolactone 8. In particular, 2-D nmr COSY 45 experiments, affording full 1H line assignments, have rigorously established the "natural" beta (axial) configuration of the C-10 hydrogen in the 19-nor lactones 5a and 8, and therefore also in the related 4a, 6a and 19-noraldosterone 7.

Renal 21-hydroxylation of 19-hydroxy-progesterone to 19-hydroxy-deoxycorticosterone.

19-Nor-deoxycorticosterone (19-nor-DOC) is a mineralocorticoid present in both rat and human urine, and it is elevated in some forms of experimental and human hypertension. Although the exact steps in the biosynthesis of 19-nor-DOC are uncertain, it is probably produced from a 19-oxygenated derivative of DOC, which undergoes 19-desmolation in the kidney. Since DOC biosynthesis is partly due to renal 21-hydroxylation of progesterone (Prog), we sought to determine whether a parallel pathway could exist for the biosynthesis of 19-hydroxy-DOC, a precursor to 19-nor-DOC. In order to test this hypothesis, authentic 19-hydroxy-progesterone was incubated with homogenized renal tissues from either rat or human sources. Formation of 19-hydroxy-DOC was found to be the major metabolite in both rat and human incubations, as demonstrated by an HPLC retention time identical to authentic 19-hydroxy-DOC. 19-Hydroxy-DOC formation was further verified by GC/MS analysis with highly sensitive selected ion recording. Since it has been demonstrated that the placenta can convert progesterone to 19-hydroxy-progesterone, the renal 21-hydroxylation of 19-hydroxy-progesterone to 19-hydroxy-DOC could be an alternate pathway of 19-nor-DOC production especially during pregnancy.