Do catechol estrogens participate in the initiation of labor?

To assess the role of catechol estrogens in the initiation of labor, we compared the levels in amniotic fluid during the second and third trimesters and from women undergoing cesarean section at term not in labor and those with spontaneous labor at term. Catechol estrogen concentrations in amniotic fluid increased significantly with the progress of pregnancy. Further, concentrations (mean +/- SE) were significantly higher in spontaneous labor at term (468.6 +/- 29.5 pg/ml) compared with those obtained during cesarean section (242.6 +/- 22.3 pg/ml) at term not in labor. We suggest that catechol estrogens, through their stimulating effects on prostaglandin synthesis, participate in the initiation of labor.

Identification of 19-norprogesterone in pregnant rat urine.

The existence of biosynthetic pathways leading to the formation of 19-nor-androgens and corticoids have been established in animals and humans. The exact biologic function of the products of these pathways in vivo has yet to be established; however, it has been shown that they possess pronounced biologic activity when administered exogenously. This report describes the identification of 19-nor-progesterone isolated from the urine of pregnant rats. The procedures used included isolation as the underivatized material and methoxime derivative by thin-layer and high-performance chromatography. The identity was further confirmed by gas chromatography/mass spectral analysis of the isolated product as the 3,20-bis-methoxime derivative. The spectra obtained from the urinary product and the authentic 19-norprogesterone-3,20-bis-methoxime were identical. A possible biologic role for 19-norprogesterone or its precursors is discussed.

Temporal relationships among the excretory patterns of 2-hydroxyestrone, estrone, estradiol, and progesterone during pregnancy in the rat.

The urinary excretion pattern of 2-hydroxyestrone, estradiol, estrone, and progesterone was examined in rats during early, mid, and late pregnancy. Progesterone increased from early to mid pregnancy and declined significantly 2 to 3 days prior to parturition, corresponding to changes observed in blood levels by others. 2-Hydroxyestrone, the major estrogen in rat urine, increased significantly 4 days prior to delivery and remained elevated until it further increased sharply the day of parturition. Urinary estradiol and estrone levels showed little change until the day of parturition, when they increased significantly. Multiple correlation analysis of the data implied that 2-hydroxyestrone and estradiol were negatively correlated at the time of implantation. The results suggest that catechol estrogens, through their effect on prostaglandin synthesis, may participate in the process of implantation as well as in the mechanism involved in the onset of labor.

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.

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.

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.

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.

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.

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.

Mineralocorticoid activity of 19-nor-corticosterone and 19-nor-progesterone in the toad bladder.

19-Nor-corticosteroids are potentially important mineralocorticoids and hypertensive agents. We tested the mineralocorticoid potency of 19-nor-progesterone (19-NOR-P) and 19-nor-corticosterone (19-NOR-B) compared with aldosterone using the toad bladder short-circuit current as a measure of sodium transport. 19-NOR-B (10(-7) M) increased sodium transport to a degree not different from that caused by aldosterone (10(-7) M). The onset of action and duration of activity also were not different from those of aldosterone. 19-NOR-P (10(-7) M), however, had no effect on sodium transport. We conclude that 19-NOR-B has significant mineralocorticoid activity, while under the conditions of these studies, 19-NOR-P exhibited no effect on sodium transport.

19-Nor-corticosteroids in health, in hypertensive states in humans including 17 alpha-hydroxylase deficiency and in the spontaneously hypertensive rat (SHR).

Since Gomez-Sanchez isolated 19-nor-DOC from the urine of rats with adrenal regeneration hypertension, we have demonstrated that 19-nor-DOC is a naturally occurring substance in other hypertensive animal models as well as in man. Certain 19-nor-corticosteroids are potent mineralocorticoids and may have a role in the regulation of systemic arterial blood pressure and could be involved in the pathogenesis of hypertension. We have previously demonstrated that 19-nor-DOC is greatly influenced by ACTH and dexamethasone but less so by high and low sodium diets in normotensive human subjects and, that 19-nor-DOC is greatly increased in some but not all hypertensive patients. Studies by Gomez-Sanchez and by our own group have shown that 19-nor-DOC is not secreted by the adrenal gland directly but rather the adrenal secretes a 19-oic-DOC precursor which is converted peripherally by extra-adrenal tissues. Biosynthesis of 19-oic-DOC has been demonstrated to occur by prior hydroxylation of DOC and progressive oxydation to the acidic form. More recently it has been shown that 19-nor-DOC is excreted in the urine of mammals as a free unconjugated compound but to a greater extent as a 21-monoglucuronide. In the studies described we will report the quantification of urinary excretion of 19-nor-DOC as a free and unconjugated compound and also as a 21-monoglucuronide in patients with hypertension as well as in patients with specific forms secondary hypertension such as that found in 17 alpha hydroxylase deficiency which is a syndrome associated with hypogonadism, hypertension and hypokalemia. In this disorder of cortisol biosynthesis adlosterone production, is not elevated and therefore other known and unknown mineralocorticoid account for the excess in mineralocorticoid activity observed. Our study demonstrated that 19-nor-DOC, the potent hypertensinogenic mineralocorticoid was elevated in both plasma and urine from a young woman with 17-alpha hydroxylase deficiency. This patient was examined for various corticosteroids in basal and ACTH-stimulated, dexamethasone-suppressed and cortisol-treated states. In the basal state, urinary and plasma 17 alpha-hydroxy corticosteroids were decreased but the 17-deoxycorticosteroids were extremely elevated including corticosterone, 18-hydroxy corticosterone, tetrahydro corticosterone, tetrahydro-deoxycorticosterone and 18 hydroxy-tetrahydro-DOC. Both basal urinary free 19-nor-DOC was markedly elevated both by HPLC and radioimmunoassay measurements.(ABSTRACT TRUNCATED AT 400 WORDS)

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.

Role of adrenal steroidogenesis in etiology of hypertension in the spontaneously hypertensive rat.

We measured peripheral adrenal steroid levels in spontaneously hypertensive rats (SHR), killed by nitrogen suffocation, at different ages during the development of hypertension. SHR became hypertensive by 8 weeks of age. Circulating plasma aldosterone (Aldo) levels of SHR gradually declined with age compared to their male Wistar-Kyoto (WKY) normotensive controls. On the other hand, corticosterone (B) concentrations rose relatively as the rats grew older, however, they were significantly lower in SHR at 16 weeks of age. Deoxycorticosterone (DOC) levels were significantly lower at 8 weeks and 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) were lower at 16 weeks of age. Steroid ratios at age 4 weeks showed significantly higher B to 18-OH-DOC and lower B to DOC, 18-OH-DOC to Aldo, and 18-OH-DOC to DOC values in SHR. Furthermore, the B to 18-OH-DOC ratio remained significantly higher at 12 weeks and the B to DOC ratio remained lower at 16 weeks. These data imply the possibility of the secretion of an unknown steroid(s) and the existence of another, fourth pathway of Aldo biosynthesis in young SHR. Thus, major alterations of adrenal steroidogenesis exist in young SHR which may be causative in the development of hypertension. After the onset of hypertension, steroidogenesis tends to return to normal, by which time, however, SHR may have developed metacorticoid hypertension.

Mineralocorticoid activity of 19-nor-DOC and 19-OH-DOC in adrenalectomized rat.

Excess mineralocorticoid activity is thought to be responsible for the increased sodium reabsorption found after adrenal enucleation, but no known mineralocorticoid has been demonstrated in quantities sufficient to account for this antinatriuresis. 19-Hydroxydeoxycorticosterone (19-OH-DOC) has been synthesized by the incubated enucleate adrenal capsule and 19-nordeoxycorticosterone (19-nor-DOC), a possible metabolite, has been found in the urine of rats with regenerating adrenal glands. To evaluate the in vivo mineralocorticoid potency of these steroids, we studied glucocorticoid-replete adrenalectomized rats and measured the sodium and potassium excretion after administration of these steroids. Our results indicate that 19-nor-DOC has equipotent antinatriuretic activity compared to aldosterone but was less kaluretic. 19-OH-DOC had no significant antinatriuretic or kaluretic activity. We conclude that 19-nor-DOC is a potent mineralocorticoid and may be responsible for the enhanced sodium reabsorption found after adrenal enucleation.

19-Nor-corticosteroids in experimental and human hypertension.

Recent reports demonstrate that the 19-nor-corticosteroids (19-nor-DOC) are naturally-occurring substances in hypertensive animal models as well as man. Since some 19-nor-corticosteroids are potent mineralocorticoids, they may have a role in regulating systemic arterial pressure and be involved in the pathogenesis of hypertension. This paper reports the probable biosynthetic pathway, factors regulating the secretion or production, and measurement of 19-nor-DOC in man and the spontaneously hypertensive rat (SHR). These studies demonstrate (1) 19-nor-DOC is greatly influenced by ACTH and dexamethasone but less so by high and low salt diets in normotensive subjects; (2) 19-nor-DOC is greatly increased in some but not all hypertensive patients; (3) 19-nor-DOC is increased in prehypertensive SHR compared to WKY rats. The likelihood of metacorticoid hypertension and possible role of other 19-nor-corticosteroids, including 19-nor-progesterone, are discussed. It can be concluded that 19-nor-corticosteroids are synthesized by extra-adrenal tissues in biologically active quantities. They are increased and possibly pathogenetic in certain states of human and experimental hypertension.

Mineralocorticoid activity of 19-nor-DOC and 19-OH-DOC in toad bladder.

Adrenal enucleation is followed by a period of increased sodium reabsorption thought to be due to excess mineralocorticoid activity. However, it has not been demonstrated that increased production of any known mineralocorticoid accounts for this antinatriuresis. Recently, 19-hydroxydeoxycorticosterone (19-OH-DOC) was found in incubates of regenerating adrenal capsules 3-4 days postenucleation and 19-nordeoxycorticosterone (19-nor-DOC) was identified in the urine of rats with regenerating adrenals. Because it was possible that these hormones might play a role in the sodium retention after adrenal enucleation, we compared the mineralocorticoid activity of these steroids to aldosterone using the toad bladder. Using short-circuit current as a measure of sodium transport, we found that 19-OH-DOC (10(-8) M) had no significant effect on sodium transport. However, 19-nor-DOC (10(-8) M) increased sodium transport to a degree not different from aldosterone (10(-8) M). Furthermore, the onset of action, duration of activity, and inhibition of effect of 19-nor-DOC by spironolactone were not different from that of aldosterone. We conclude that 19-nor-DOC exhibits a significant effect on sodium transport and thus has the potential to play a role in the sodium retention following adrenal enucleation. Under the conditions of these studies, 19-OH-DOC exhibited no effect on sodium transport.