Male pseudohermaphroditism due to multiple defects in steroid-biosynthetic microsomal mixed-function oxidases. A new variant of congenital adrenal hyperplasia

A six-month-old 46,XY infant with a female phenotype and ambiguous genitalia was evaluated for male pseudohermaphroditism. The principal findings were (1) low basal plasma levels of all measured C19 steroids and their sulfates, which were unchanged or only minimally increased after stimulation with human chorionic gonadotropin or ACTH, (2) no urinary metabolites of C19 11-deoxy steroids, and decreased amounts of C19 11-oxosteroids, (3) normal basal plasma cortisol levels and normal urinary excretion of cortisol metabolites, (4) high plasma corticosterone and deoxycorticosterone levels and elevated urinary excretion of their metabolites, (5) high plasma progesterone and pregnenolone levels and increased urinary excretion of pregnanediol and pregnenediol, (6) high plasma 17 alpha-hydroxyprogesterone and 21-deoxycortisol levels and increased urinary excretion of pregnanetriol, 17 alpha-hydroxypregnanolone, and pregnenetriolone, (7) high plasma and urinary levels of 5-pregnene-3 beta,20 alpha-diol sulfate, (8) low plasma levels of 21-hydroxy-pregnenolone and 5-pregnene-3 beta,17 alpha, 20 alpha-triol sulfate, (9) high plasma ACTH levels, and (10) suppression of the high plasma steroid levels by dexamethasone. The unusual pattern of plasma and urinary steroids indicated that this child had multiple abnormalities of steroid-biosynthetic microsomal mixed-function oxidases--21-hydroxylase, 17 alpha-hydroxylase, and 17,20 desmolase. The deficit in the activities of the first two enzymes resulted in decreased cortisol synthesis with subsequent increased ACTH secretion and adrenocortical hyperplasia. The male pseudohermaphroditism resulted from deficient testosterone synthesis due to deficiency of 17 alpha-hydroxylase and 17,20 desmolase. The mother and two sisters of the affected child had evidence of mild 17 alpha-hydroxylase deficiency.

Adrenal circadian system in young and elderly human subjects: a comparative study

Circadian changes in plasma 18-hydroxy-11-deoxycorticosterone (18-OH-DOC), total and unbound cortisol were studied in four groups: seven healthy young men, six elderly men, six elderly women and six elderly demented patients of both sexes. The daily activities of the subjects were synchronous; blood samples were taken every 4 h and 4 hourly urine samples were collected only from the young men. A circadian rhythm was defined for plasma 18-OH-DOC, total and unbound cortisol in all groups; the secretory patterns of these steroids were parallel, as were the profiles of urinary 18-OH-DOC and unconjugated cortisol. When compared with respect to sex, the 24-h mean level of total cortisol was higher in women; that of unbound cortisol was higher in the three groups of elderly patients than in the young men. No major changes in plasma steroids were observed between elderly demented patients (mainly women) and healthy elderly women. The phasing of total and unbound cortisol showed no major modifications with age, sex or senile dementia. Acrophases of 18-OH-DOC were earlier in elderly patients than in young men. Amplitudes were not modified with sex in elderly patients but were always lower in the demented patients. A circadian rhythm was defined for 18-OH-DOC, unconjugated cortisol, 17-hydroxycorticosteroids (17-OH-CS) and 17-ketosteroids in the urine of the young men. The acrophases of 18-OH-DOC and unbound cortisol were close, as were those of 17-OH-CS and 17-ketosteroids. The lag was short between the acrophases of 18-OH-DOC in plasma and urine and between those of plasma unbound cortisol and urinary unconjugated cortisol; it was much larger between the acrophases of plasma total cortisol and 17-OH-CS. Thus, the process of ageing, and the possible alterations in the central nervous system which are often seen in normal ageing, induced no major modifications in the temporal organization of adrenocortical function, even in subjects who were very advanced in age.

Plasma mineralocorticoids, plasma renin, and urinary kallikrein in salt-sensitive and salt-resistant rats

Plasma aldosterone, deoxycorticosterone (DOC), 18-hydroxy-deoxycorticosterone (18OH-DOC), and corticosterone were measured in Dahl salt-sensitive (S) and salt-resistant (R) rats. Plasma corticosterone and DOC were not different between strains but plasma aldosterone was decreased and plasma 18OH-DOC increased in S compared to R. Plasma renin activity and urinary kallikrein excretion were both lower in S than R. Urinary kallikrein is known to vary directly with mineralocorticoid activity and 18OH-DOC is a weak mineralocorticoid. The lower urinary kallikrein in the presence of elevated 18OH-DOC could mean that urinary kallikrein differences between S and R are under independent genetic control from 18OH-DOC.

Adrenocortical hormones, ageing and mental condition: seasonal and circadian rhythms of plasma 18-hydroxy-11-deoxycorticosterone, total and free cortisol and urinary corticosteroids

The circannual rhythms of plasma 18-hydroxy-11-deoxycorticosterone (18-OH-DOC), total and free cortisol have been documented on a circadian basis in January, March, June and October in seven young men (24 years old), six elderly men, six elderly women and six elderly demented subjects, both men and women, in their eighties. Blood samples were drawn every 4 h over a 24-h period at each sampling session and urine samples were collected at 4-h intervals only from the young men. A circadian rhythm of 17-hydroxy-corticosteroids (17-OH-CS), 17-ketosteroids (17-KS), urinary free cortisol and 18-OH-DOC was defined for each of the four seasons with stable acrophases throughout the year and the same excretory profiles. A circannual rhythm was validated in young men for 17-OH-CS, urinary free cortisol and 18-OH-DOC but not for 17-KS. A circadian rhythm of plasma free cortisol, the active form of the hormone, plasma total cortisol and plasma 18-OH-DOC was validated in all groups and at all the seasons at which samples were taken. The secretory profiles of 18-OH-DOC, free and total cortisol were very similar, with no differences attributable to age, sex or mental condition except for the levels of plasma free cortisol and 18-OH-DOC which were higher and lower respectively in the elderly subjects. Whereas a circannual rhythm of plasma 18-OH-DOC was validated for all groups, a circannual rhythm of both free and total cortisol in the plasma was validated in young men but not in any group of elderly subjects. This loss of the circannual rhythmicity of cortisol in the elderly may reflect the decrease with age of the capacity to adapt to seasonal external factors.

Gonadectomy-induced reduction of blood pressure in adult spontaneously hypertensive rats

Adult male and female spontaneously hypertensive rats (SHR-Okamoto, Kyoto) were gonadectomized when they were 17 weeks old. Intact SHR showed a progressive increase of their blood pressure with growth, attaining systolic pressure levels of 194-208 in males and 163-173 mmHg in females when they were 29-30 weeks old. During this same period, the gonadectomized animals showed a significant reduction in blood pressure ranging from 168-175 in males and from 158-163 mmHg in females. These studies indicate that male and female SHR gonadectomized at 17 weeks of age do not show the progressive blood pressure rise that occurs in intact SHR. There was no change in heart rate in either sex. Corticosterone (B) levels in plasma were increased in the orchidectomized males, and 18-OH-DOC levels in plasma were increased in the adrenal glands of ovariectomized females indicating that these hormonal changes probably do not play a role in SHR hypertension. It appears that gonadal and other hormones are involved in the pathogenesis of SHR hypertension.

The regulation of plasma 18-hydroxy 11-deoxycorticosterone in man

18-hydroxy 11-deoxycorticosterone (18-OH DOC), a weak mineralocorticoid, was estimated by a radioimmunoassay procedure after purification in 49 patients with hypertension and 38 normal control subjects. The sensitivity of the method was 2-4 pg; there was no detectable blank, and the precision was 9-10%. In normal subjects the absolute plasma levels were similar to those of aldosterone. ACTH administration produced a 23-fold increase, and sodium restriction resulted in a 4-fold increase (5.4+/-0.7-20.5+/-3.0 ng/dl). On the other hand, the plasma levels of 18-OH DOC declined by nearly 50% with upright posture or angiotensin II infusion. During both of these procedures, plasma aldosterone levels significantly increased. Patients with normal and low renin hypertension had similar changes in plasma 18-OH DOC levels with sodium restriction. However, the mean high sodium level in the normal renin essential hypertension group (11.6+/-1.6 ng/dl) was significantly greater (P is less than 0.001) than in the control group (5.4+/-0.7 ng/dl). In addition, at least 22% and perhaps as high as 37% of the hypertensive subjects had levels greater than the upper limits of normal on a high sodium intake. Differences between the groups were less impressive in the sodium-restricted studies. There were no significant differences in age, duration of hypertension, sodium balance, serum sodium, potassium, or blood urea nitrogen in those patients who had elevated levels of plasma 18-OH DOC. Patients with primary aldosteronism had levels within the normal range on both dietary intake. However, in contrast to the other groups there were no significant changes in the plasma levels with sodium restriction. Thus, a significant number of patients with essential hypertension presumably have an alteration in 18-OH DOC secretion.

17 alpha-hydroxylase deficiency: mineralocorticoid hormone profiles in an affected family

The plasma concentrations of mineralocorticoid hormones, basal and after stimulation and suppression with ACTH, can identify the heterozygotes in a family with two siblings with 17 alpha-hydroxylase deficiency. Both parents and one sibling had elevated levels of plasma deoxycorticosterone, corticosterone, 18-hydroxydeoxycorticosterone, and 18-hydroxycorticosterone, but normal cortisol and aldosterone concentrations. Stimulation with ACTH effected additional increases in the elevated steroid and cortisol levels, but not in aldosterone, further increasing the discrepancy and the ratio between 18-hydroxycorticosterone and aldosterone. One sibling had normal steroid patterns and an 18-hydroxycorticosterone to aldosterone ratio. Suppression of ACTH restored the steroids to low normal levels. In addition, the ratio of the gas chromatographic analysis of the total major urinary metabolites of corticosterone to total metabolites of cortisol was greater, and the sum of urinary androsterone and etiocholanolone to total corticosterone and cortisol metabolites was less in the heterozygotes than in normal subjects. This identifies deficient 17-hydroxylation, which is required for the production of cortisol and C-19 steroids. These criteria appear unique for the 17 alpha-hydroxylase defect in the heterozygote.

Sex differences in corticosteroids in man

The serum concentrations of progesterone (P), 17-OH-progesterone (17-OHP), 11-deoxycorticosterone (DOC), corticosterone (B), 11-deoxycortisol (S), 18-OH-11-deoxycorticosterone (18-OH-DOC), aldosterone (Aldo) and cortisol (F) were measured in 18 normal men (M), 14 normal women in the folicular phase (FF) and 14 normal women in the luteal phase (FL) of menstrual cycle from blood samples obtained between 0800 and 0900 h. Steroids were estimated by a sensitive and specific radioimmunoassay allowing the simultaneous determination of all steroids studied from one 3 ml serum sample. The mean steroid concentrations (ng/1dl) in FF were found to be as follows: P, 20.3; 17-OHP, 58; DOC, 3.8; B, 241; S, 20.7; 18-OH-DOC, 12.3; Aldo, 8.8; F, 9860. Apart from P, steroid concentrations in FF were significantly lower than in M. Serum 17-OHP, DOC, B and Aldo in FF were significantly lower than in FL. With the exception of P, there were no significant differences of mean steroid concentrations between M and FL.

The zonal origins of the mineralocorticoid hormones in the 21-hydroxylation deficiency of congenital adrenal hyperplasia

The 0800 h plasma concentrations of the mineralocorticoid hormones, 18-hydroxydeoxycorticosterone (18-OHDOC), deoxycorticosterone (DOC), corticosterone, 18-hydroxycorticosterone (18-OHB), and aldosterone, in six patients with nonsalt-losing congenital adrenal hyperplasia revealed two groupings of these steroids: in one group, DOC, 18-OHB, and aldosterone were significantly elevated (P less than 0.001) at 51.7 +/- 18.0, 70.8 +/- 14.2, and 22.7 +/- 3.0 ng/dl, respectively; in the other group, corticosterone and 18-OHDOC were normal at 363.6 +/- 76.0 and 7.8 +/- 1.1 ng/dl, respectively. No significant increases in response to upright posture were observed in DOC, 18-OHB, or aldosterone. After a 1-h Cortrosyn stimulation test, the already elevated levels of DOC, 18-OHB, and aldosterone showed slight additional increases, but the normal levels of corticosterone and 18-OHDOC changed little within the normal unstimulated range. In these patients certain mineralocorticoid hormone patterns permit the identification of the zonal origins of steroids. The normal and fixed levels of 18-OHDOC and corticosterone, zona fasciculata steroids, are similar to those of cortisol and imply deficiency of formation and of their precursor, zona fasciculata DOC, a 21-hydroxylated steroid. Both the mineralocorticoid and glucocorticoid pathways distal to 21-hydroxylation are impaired in the zona fasciculata. However, the elevated and partially responsive levels of DOC, 18-OHB, and aldosterone imply that there is greater activation of 21-hydroxylation in the zona glomerulosa than in the zona fasciculata, with its normal fixed steroid levels, and that the elevated level of DOC is primarily from this zone.

Radioimmunoassay of 18-hydroxy-11-deoxycorticosterone in plasma

A method is described for the radioimmunoassay of 18-OH-DOC using antibodies generated in rabbits against the carboxymethoxime derivative coupled to bovine serum albumin. The procedure uses 4 ml of plasma with intra and interassay variations of 8 and 9% respectively. Standard 18-OH-DOC added to plasma from an adrenalectomized patient gave a regression equation, Y=0.974X+/-2.210 and a correlation coefficient of 0.999. The only cross reacting steroid, 18-OH-B which may lead to falsely high levels is removed by a single thin layer chromatographic step. Blood levels in normal subjects agree closely with those calculated indirectly by metabolic clearance and secretion rate measurements. ACTH stimulation produced an 18-fold increase in plasma concentration while dexamethasone suppression decreased levels 3-fold. Four hours in the upright position resulted in a decreased plasma concentration while aldosterone increased. No significant response to dietary sodium restriction could be demonstrated.

Effect of aminoglutethimide on blood pressure and steroid secretion in patients with low renin essential hypertension

An inhibitor of adrenal steroid biosynthesis, aminoglutethimide, was administered to seven patients with low renin essential hypertension, and the antihypertensive action of the drug was compared with its effects on adrenal steroid production. In all patients aldosterone concentrations in plasma and urine were within normal limits before the study. Mean arterial pressure was reduced from a pretreatment value of 117+/-2 (mean+/-SE) mm Hg to 108+/-3 mm Hg after 4 days of aminoglutethimide therapy and further to 99+/-3 mm Hg when drug administration was stopped (usually 21 days). Body weight was also reduced from 81.6+/-7.2 kg in the control period to 80.6+/-7.0 kg after 4 days of drug treatment and to 80.1+/-6.7 kg at the termination of therapy. Plasma renin activity was not significantly increased after 4 days of treatment but had risen to the normal range by the termination of aminoglutethimide therapy. Mean plasma concentrations of deoxycorticosterone and cortisol were unchanged during aminoglutethimide treatment whereas those of 18-hydroxydeoxycorticosterone, progesterone, 17alpha-hydroxyprogesterone, and 11-deoxycortisol were increased as compared to pretreatment values. In contrast, aminoglutethimide treatment reduced mean plasma aldosterone concentrations to about 30% of control values. Excretion rates of 16beta-hydroxydehydroepiandrosterone, 16-oxo-androstenediol, 17-hydroxycorticosteroids and 17-ketosteroids, and the secretion rate of 16beta-hydroxydehydroepiandrosterone were not significantly altered by aminoglutethimide treatment whereas the excretion rate of aldosterone was reduced from 3.62+/-0.5 (mean+/-SE) in the control period to 0.9+/-0.2 mug/24 h after 4 days and to 1.1+/-0.3 mug/24 h at the termination of aminoglutethimide treatment. The gradual lowering of blood pressure and body weight during aminoglutethimide therapy is consistent with the view that the antihypertensive effect of the drug is mediated through a reduction in the patients' extracellular fluid volume, probably secondary to the persistent decrease in aldosterone production. The observation that chronic administration of aminoglutethimide lowered blood pressure in these patients and elevated their plasma renin activity to the normal range without decreasing production of the adrenal steroids, deoxycorticosterone, 18-hydroxydeoxycorticosterone, and 16beta-hydroxydehydroepiandrosterone, makes it unlikely that these steroids are responsible either for the decreased renin or the elevated blood pressure in patients with low renin essential hypertension.

Distinctive plasma aldosterone, 18-hydroxycorticosterone, and 18-hydroxydeoxycorticosterone profile in the 21-, 17 alpha-, and 11 beta-hydroxylase deficiency types of congenital adrenal hyperplasia

Forms of congenital adrenal hyperplasia resulting from deficient steroid hydroxylation at positions 21, 17 alpha, and 11 beta have several similar clinical and biochemical characteristics. Biochemical diagnosis has been dependent on the demonstration of elevated plasma or urinary concentrations of metabolites of the immediate biosynthetic precursor before the enzymatic block, especially after stimulation with adrenocorticotropin. Aldosterone, 18-hydroxycorticosterone, and 18-hydroxydeoxycorticosterone are not closely involved nor are they immediate precursors of any of these enzymatic defects. However, simultaneous determination of the baseline plasma levels of these steroids in patients with nonsodium-losing 21-hydroxylase deficiency (n = 12), 17 alpha-hydroxylase deficiency (n = 6), and 11 beta-hydroxylase deficiency (n = 2) revealed a consistent and distinct pattern (mean +/- SEM in nanograms per deciliter): aldosterone (28.1 +/- 2.8) and 18-hydroxycorticosterone (84.5 +/- 9.2) levels were elevated and 18-hydroxydeoxycorticosterone (8.0 +/- 0.8) levels were within normal limits in 21-hydroxylase deficiency; 18-hydroxycorticosterone (327.2 +/- 73.9) and 18-hydroxydeoxycorticosterone (236.0 +/- 33.8) levels were elevated and aldosterone (3.5 +/- 0.6) levels were reduced in 17 alpha-hydroxylase deficiency; levels of all three steroids (aldosterone 2.6 +/- 0.4, 18-hydroxycorticosterone 5.1 +/- 3.1, 18-hydroxydeoxycorticosterone 0.9 +/- 0.1) were reduced in 11 beta-hydroxylase deficiency. It is suggested that simultaneous measurement of these three steroids can be useful in identifying and further characterizing each of these forms of congenital adrenal hyperplasia.

Influence of an enriched dietary sodium chloride regime during gestation and suckling and post-natally on the ontogeny of hypertension in the rat

Brattleboro rats without diabetes insipidus were subjected to sodium chloride enrichment (20-fold increase in dietary salt) at various stages of their development. Salt supplementation in the adult rat produced higher systolic blood pressure (SBP), particularly in males (142 +/- 3 versus 110 +/- 3 mmHg in control. The blood pressures of females on salt-supplemented diets during pregnancy decreased from 136 +/- 1 to 121 +/- 2 mmHg, although throughout this period the blood pressures for these rats were greater than for the control pregnant rats. Pregnant females on salt-supplemented diets also showed higher sodium concentrations in the amniotic fluid compared with controls (155 +/- 3.4 versus 134.1 +/- 6.0 mmol/l). Salt supplemented lactating mothers produced milk with similar sodium concentrations to those of the controls, but the urinary sodium concentrations of pups suckling on the former were greater than in the controls. It is concluded that the suckling pups were also salt-enriched. Rats were submitted to salt-enriched regimes in utero, during suckling, post-weaning and post-pubertally, or permutations thereof. Salt supplementation post-weaning led to consistent elevation in arterial blood pressure with males being more susceptible than females. The degree of elevation was increased if the salt-supplement was present during suckling (132 +/- 1 versus 112 +/- 1 mmHg) and was greatest when the salt-supplemented regime was administered both in utero and during the post-weaning period (154 +/- 2 versus 112 +/- 1 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Mineralocorticoid response to low dose adrenocorticotropin infusion

The adrenocorticoid responses to low dose ACTH of plasma aldosterone (aldo), corticosterone (B), 11-deoxycorticosterone (DOC), 18-hydroxycorticosterone (18-OHB), 18-hydroxycorticosterone (18-OH-DOC), and cortisol (F) were compared. Alpha ACTH-)1-24) was infused beginning at 0800 h at increasing rates from 12.5-200 mIU/30 min in supine normal subjects under the following conditions: 1) regular Na (120 meq) diet, 2) low Na (10 meq) diet, 3) dexamethasone preadministration (0.5 mg every 6 h for 48 h), and 4) night study (2000 h; 120 meq Na intake). Plasma 18-OH-DOC and B demonstrated quantitatively the greatest responses to ACTH, while DOC and 18-OHB responses were intermediate. Increments in aldo and F were least after ACTH and were maximum at 50 mIU/30 min ACTH, whereas other corticosteroids demonstrated linear responses up to infusion rates of 200 mIU/30 min. All corticosteroids, however, were similar in their threshold responses to ACTH which were at infusion rates of approximately 7-9 mIU/30 min. Na restriction enhanced aldo and 18-OHB responses to ACTH 2- to 3-fold but did not alter the other corticosteroid responses. Dexamethasone pretreatment augmented aldo, 18-OHB, and F responses but did not change the responsitivity of the other corticosteroids to ACTH. Adrenal corticosteroid responses to ACTH were not significantly different between 0800 and 2000 h in subjects on 120-meq Na intake. Thus, corticosteroids show markedly different responses to physiological doses of ACTH, which may have more importance in their regulation than heretofore proposed. Dexamethasone pretreatment enhances aldo, 18-OHB, and F responses to ACTH but does not affect the responses of other corticosteroids. Contrary to reports in experimental animals, corticosteroid responses to ACTH in man do not differ from day to night.

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.

Inappropriate elevation of the aldosterone/plasma renin activity ratio in hypertensive patients with increases of 11-deoxycorticosterone and 18-hydroxy-11-deoxycorticosterone: a subtype of essential hypertension?

Among 436 patients with hypertension unrelated to any renal lesion, renovascular damage, pheochromocytoma, Cushing's syndrome or hyperthyroidism, 15 patients had low plasma renin activity (PRA) and elevated plasma aldosterone concentrations in the upright position and resultant high aldosterone/PRA ratios: 8 with aldosterone-producing adenoma (APA; group 1) and 7 with idiopathic hyperaldosteronism (IHA; group 2). Thirty-nine patients had suppressed PRA in the presence of normal plasma aldosterone levels and moderately elevated aldosterone/PRA ratios (group 3). Thirty of them had elevated plasma 11-deoxycorticosterone (DOC) and 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) concentrations (group 3a) and 9 of them had normal levels of those mineralocorticoids (group 3b). The rest of them (382 patients) had low aldosterone/PRA ratios (group 4). Adrenal scintigraphy with dexamethasone pretreatment revealed [13I]-cholesterol accumulation not only in patients with APA (unilateral) or IHA (bilateral), but also in patients of group 3a (bilateral). In patients in groups 3a and 3b adrenal size (especially thickness), as measured by computed tomography (CT scan), was enlarged, as in patients with IHA (group 2), and was significantly greater than in patients of group 4 (p less than 0.001). Spironolactone reduced blood pressure in all tested patients of group 3a, and the removal of adrenal tumor or hyperplastic tissue normalized blood pressure in patients of groups 1, 2 and 3a. Excised adrenal glands exhibited cortical hyperplasia with or without nodular hyperplasia in patients of group 3a. Good agreement was found between the actual size of the excised tissue and the measurement obtained by CT scan. Since beta-endorphin and beta-lipotropin were depressed in patients of group 3a, it is suggested that an unknown pituitary substance stimulates the adrenal cortex to release too large amounts of DOC and 18-OH-DOC and inappropriate secretion of aldosterone.

New mineralocorticoids and adrenocorticosteroids in hypertension

Alterations in steroidogenesis have been demonstrated in experimental and human hypertension. It is highly likely that increased secretion of the nonaldosterone mineralocorticoid deoxycorticosterone (DOC) and 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) may initiate or perpetuate hypertension, or both. It is possible that 16 beta-hydroxydehydroeplandrosterone (16beta-OH-DHEA) directly induces the hypertensive process in animals. The significance of the findings of increased secretion of 16 alpha, 18-dihydroxy-11-deoxycorticosterone (16alpha, 18-diOH-DOC) and dehydroepiandrosterone sulfate (DHEA-S) cannot now be appreciated. Neither has been examined experimentally for its ability to induce hypertension, and the former compound is not a mineralocorticoid. It does possess the curious property of increasing mineralocorticoid activity of other steroids, by altering either their metabolism or mode of action. Variations in the mineralocorticoid hypertensive syndrome or, more aptly, the steroid hypertensive syndrome could account for the hypertension in a substantial portion of patients with reduced plasma renin activity.

Adrenocorticotropin inhibition of mineralocorticoid hormone production

1. Adrenocorticotropin (ACTH)-induced steroidogenesis, obtained by continuous administration of ACTH for 3 days, produces in man (a) sustained elevations of plasma deoxycorticosterone and cortisol concentrations, (b) transient elevations of plasma aldosterone and 18-hydroxycorticosterone concentrations that return to near-control values, and (c) brisk initial increases in plasma 18-hydroxydeoxycorticosterone and corticosterone concentrations that fall to 20-68% of peak values 30 h thereafter. 2. Dexamethasone (8 mg/day, orally) treatment for 2 days in man permits a greater postural increase in plasma aldosterone and 18-hydroxycortisone concentrations. A dampening effect of ACTH is suggested. 3. An ACTH-initiated inhibition of 11 beta- and 18-hydroxylation is proposed to be operative in regulation of mineralocorticoid hormones.

The measurement of 18-hyroxy-11-deoxycorticosterone in human plasma by radioimmunoassay

A radioimmunoassay method for the measurement of plasma levels of 18-hydroxy-11 -deoxycorticosterone (18 -OH-DOC) has been developed. The antiserum against 18-OH-DOC was produced in rabbits immunized against 18-OH-DOC-3-oxime-bovine serum albumin. Plasma (1-2 ml) was extracted with dichloromethane and chromatographed on paper. The purified extracts were incubated with antiserum at a 1/22,000 dilution for 1/2 hour at 37 degrees C and for 2 hours at 4 degrees C. Saturated ammonium sulfate was used to separate free from bound 18-OH-DOC. 1,2-3H-18-OH-DOC was added to all samples to correct for losses and to determine the percent free. Pyridine (0.1%) was added to solvents to maintain the stability of 18-OH-DOC. Recovery after extraction was 58 +- 8 (S.D)%. The accuracy and precision of the method were acceptable, and a sensitivity of 2 pg per sample enabled the measurement of very low levels of 18-OH-DOC. High specificity was demonstrated by a low blank value (0 +- 0.2 pg) and by demonstrating that alternative paper chromatography separation systems gave results not differing significantly from those obtained by the present method. The mean 8AM plasma 18-OH-DOC level was 8.5 +- 1.2 ng per 100 ml in18 normotensive control subjects. There was a marked response of plasma 18-OH-DOC to ACTH stimulation and dexamethasone suppression and a significant increase after 3 hours upright posture.

Regulation of 18-hydroxydeoxycorticosterone in the rat

Simultaneous measurements of plasma 18-hydroxydeoxycorticosterone (18 OH-DOC), corticosterone, and aldosterone were performed in the rat by using RIA. Under basal conditions, 18 OH-DOC levels averaged 11.3 +/- 3.7 (SE) ng/ml. Plasma concentrations were increased 8-fold (86.8 +/- 8.0 ng/ml) 1 h after 1 U sc ACTH. Dexamethasone suppressed 18 OH-DOC to less than 1.5 ng/ml, irrespective of Na+ intake. Neither Na+ depletion nor Na+ loading had any influence on 18 OH-DOC levels. Excellent correlation between 18 OH-DOC and corticosterone (r = 0.90, P less than 0.001) was observed, whereas there was none between 18 OH-DOC and aldosterone (r = 0.061, P greater than 0.6). In the rat, 18 OH-DOC is an ACTH-dependent steroid which does not appear to be under the influence of the renin-angiotensin system.