Plasma Deoxycorticosterone Research Articles

A practical approach to supported liquid extraction and measurement of 18 steroids in plasma and serum by targeted liquid chromatography tandem mass spectrometry

Chromatography combined with mass spectrometry is a gold standard technique for steroid measurement, however the type of sample preparation, the dynamic range and reliability of the calibration curve, the chromatographic separation and mass spectrometry settings ultimately determine the success of the method. The steroid biosynthetic pathway is conserved in higher mammals and literature demonstrates that the concentration ranges of different steroid groups are relatively comparable across species. We sought to develop a robust and reliable multi steroid targeted analysis method for blood that would have wide application across higher mammals. The method was developed following bioanalytical method validation guidelines to standards typically applied to human clinical studies, including isotopically labelled internal standards where at all possible. Here we describe the practical approach to a 96-well supported liquid extraction (SLE) method of extraction from plasma (200 µL) using an Extrahera liquid handling robot (Biotage, Sweden), including quality control samples, followed by a comprehensive separation and targeted LC-MS/MS analysis of 18 steroids in plasma (pregnenolone, progesterone, 17α-hydroxyprogesterone, 11-deoxycorticosterone, corticosterone, 11-dehydrocorticosterone, aldosterone, 11-deoxycortisol, 21-deoxycortisol, cortisol, cortisone, androstenedione, testosterone, 5α-dihydrotestosterone, dehydroepiandrosterone, estrone, 17β-estradiol and estriol).•SLE in a 96-well format of up to 74 biological plasma samples, enriched with multiple isotopically labelled internal standards, a 12-point aqueous calibration curve, and 6 serum quality controls, designed to monitor long-term performance of the method•Chromatographic separation of multiple steroids along the gradient, with ammonium fluoride mobile phase additive to improve sensitivity, followed by electrospray ionisation and constant polarity switching•Aqueous calibration standards that cover physiologically relevant ranges - high nanomolar glucocorticoids, low nanomolar androgens and picomolar ranges for estrogens and steroid intermediates.

Mass spectrometry-based steroid profiling in primary bilateral macronodular adrenocortical hyperplasia.

Biochemical characterization of primary bilateral macronodular adrenocortical hyperplasia (PBMAH) by distinct plasma steroid profiles and its putative correlation to disease has not been previously studied. LC-MS/MS-based steroid profiling of 16 plasma steroids was applied to 36 subjects (22 females, 14 males) with PBMAH, 19 subjects (16 females, 3 males) with other forms of adrenal Cushing's syndrome (ACS), and an age and sex-matched control group. Germline ARMC5 sequencing was performed in all PBMAH cases. Compared to controls, PBMAH showed increased plasma 11-deoxycortisol, corticosterone, 11-deoxycorticosterone, 18-hydroxycortisol, and aldosterone, but lower progesterone, DHEA, and DHEA-S with distinct differences in subjects with and without pathogenic variants in ARMC5. Steroids that showed isolated differences included cortisol and 18-oxocortisol with higher (P < 0.05) concentrations in ACS than in controls and aldosterone with higher concentrations in PBMAH when compared to controls. Larger differences in PBMAH than with ACS were most clear for corticosterone, but there were also trends in this direction for 18-hydroxycortisol and aldosterone. Logistic regression analysis indicated four steroids - DHEA, 11-deoxycortisol, 18-oxocortisol, and corticosterone - with the most power for distinguishing the groups. Discriminant analyses with step-wise variable selection indicated correct classification of 95.2% of all subjects of the four groups using a panel of nine steroids; correct classification of subjects with and without germline variants in ARMC5 was achieved in 91.7% of subjects with PBMAH. Subjects with PBMAH show distinctive plasma steroid profiles that may offer a supplementary single-test alternative for screening purposes.

Abstract P2025: Primary Aldosteronism Decreases Insulin Secretion and Increases Insulin Clearance in Humans

Primary aldosteronism is associated with an increased risk of diabetes, but the mechanism is uncertain. We enrolled 9 patients with primary aldosteronism and assessed insulin secretion and insulin sensitivity beforte and after 3-12 months after either adrenalectomy (n-6) or medical treatment (n=3). Plasma 8AM Aldosterone ( p =0.02) and 11-deoxycorticosterone ( p =0.02) decreased after treatment, whereas cortisol was unchanged ( p =0.57). Systolic blood pressure (131.1±3.6 vs 124.3±7.7; p =0.43), serum potassium (3.7±0.1 vs 4.1±0.1 mEq/L; p =0.063), and creatinine (1.1±0.1 vs 1.2±0.1 mg/dL; p =0.35) were similar after treatment. During hyperglycemic clamps, we infused glucose to increase plasma glucose to a target of 200mg/dL ( a ). The insulin response ( b , 218.6±39.8 vs 403.1±42.0 pM insulin mean at 90-120 min, p =0.004) and L-arginine stimulated insulin response ( c) increased compared to Pre-Treatment assessment. C-peptide results were similar to insulin alterations. Comparison to control subjects matched for age, race, sex, and BMI ( Figure , gray line and area indicating mean±95%CI) indicated that insulin secretion after treatment was comparable to healthy individuals. During hyperinsulinemic-euglycemic clamps, insulin clearance (steady state insulin divided by insulin infusion rate) increased after treatment (855±68 vs 615±57 mL/min, p =0.031). Insulin sensitivity decreased after treatment (30.7±2.1 vs 18.5±1.6 M/I; p =0.016), but disposition index was unchanged (acute insulin response x M/I; p =0.81).

Discovering Pain in Newborn Infants.

Randomised Trial of Fentanyl Anesthesia in Preterm Babies Undergoing Surgery: Effects on the Stress Response. By Anand KJ, Sippell WG, and Aynsley-Green A. Lancet 1987; 1:243-8. Reprinted with permission.In a randomised controlled trial, preterm babies undergoing ligation of a patent ductus arteriosus were given nitrous oxide and D-tubocurarine, with (n = 8) or without (n = 8) the addition of fentanyl (10 μg/kg intravenously) to the anesthetic regimen. Major hormonal responses to surgery, as indicated by changes in plasma adrenaline, noradrenaline, glucagon, aldosterone, corticosterone, 11-deoxycorticosterone, and 11-deoxycortisol levels, in the insulin/glucagon molar ratio, and in blood glucose, lactate, and pyruvate concentrations were significantly greater in the nonfentanyl than in the fentanyl group. The urinary 3-methylhistidine/creatinine ratios were significantly greater in the nonfentanyl group on the second and third postoperative days. Compared with the fentanyl group, the nonfentanyl group had circulatory and metabolic complications postoperatively. The findings indicate that preterm babies mount a substantial stress response to surgery under anesthesia with nitrous oxide and curare and that prevention of this response by fentanyl anesthesia may be associated with an improved postoperative outcome.

Sex‐dependent changes in neuroactive steroid concentrations in the rat brain following acute swim stress

Sex differences in hypothalamic‐pituitary‐adrenal (HPA) axis activity are well established in rodents. In addition to glucocorticoids, stress also stimulates the secretion of progesterone and deoxycorticosterone (DOC) from the adrenal gland. Neuroactive steroid metabolites of these precursors can modulate HPA axis function; however, it is not known whether levels of these steroids differ between male and females following stress. In the present study, we aimed to establish whether neuroactive steroid concentrations in the brain display sex‐ and/or region‐specific differences under basal conditions and following exposure to acute stress. Brains were collected from male and female rats killed under nonstress conditions or following exposure to forced swimming. Liquid chromatography‐mass spectrometry was used to quantify eight steroids: corticosterone, DOC, dihydrodeoxycorticosterone (DHDOC), pregnenolone, progesterone, dihydroprogesterone (DHP), allopregnanolone and testosterone in plasma, and in five brain regions (frontal cortex, hypothalamus, hippocampus, amygdala and brainstem). Corticosterone, DOC and progesterone concentrations were significantly greater in the plasma and brain of both sexes following stress; however, the responses in plasma were greater in females compared to males. This sex difference was also observed in the majority of brain regions for DOC and progesterone but not for corticosterone. Despite observing no stress‐induced changes in circulating concentrations of pregnenolone, DHDOC or DHP, concentrations were significantly greater in the brain and this effect was more pronounced in females than males. Basal plasma and brain concentrations of allopregnanolone were significantly higher in females; moreover, stress had a greater impact on central allopregnanolone concentrations in females. Stress had no effect on circulating or brain concentrations of testosterone in males. These data indicate the existence of sex and regional differences in the generation of neuroactive steroids in the brain following acute stress, especially for the 5α‐reduced steroids, and further suggest a sex‐specific expression of steroidogenic enzymes in the brain. Thus, differential neurosteroidogenesis may contribute to sex differences in HPA axis responses to stress.

The Aldosterone Synthase Inhibitor FAD286 is Suitable for Lowering Aldosterone Levels in ZDF Rats but not in db/db Mice.

Inhibition of aldosterone synthase is an alternative treatment option to mineralocorticoid receptor antagonism to prevent harmful aldosterone actions. FAD286 is one of the best characterized aldosterone synthase inhibitors to date. FAD286 improves glucose tolerance and increases glucose-stimulated insulin secretion in obese and diabetic ZDF rats. However, there is limited knowledge about the dose-dependent effects of FAD286 on plasma aldosterone, corticosterone, and 11-deoxycorticosterone in ZDF rats and in db/db mice, a second important rodent model of obesity and type 2 diabetes. In addition, effects of FAD286 on plasma steroids in mice and rats are controversial. Therefore, obese Zucker diabetic fatty (ZDF) rats and db/db mice were treated with FAD286 for up to 15 weeks and plasma steroids were evaluated using highly sensitive liquid chromatography-tandem mass spectrometry. In ZDF rats, FAD286 (10 mg/kg/d) treatment resulted in nearly complete disappearance of plasma aldosterone while corticosterone levels remained unaffected and those of 11-deoxycorticosterone were increased ~4-fold compared to vehicle control. A lower dose of FAD286 (3 mg/kg/d) showed no effect on plasma aldosterone or corticosterone, but 11-deoxycorticosterone was again increased ~4-fold compared to control. In contrast to ZDF rats, a high dose of FAD286 (40 mg/kg/d) did not affect plasma aldosterone levels in db/db mice although 11-deoxycorticosterone increased ~2.5-fold. A low dose of FAD286 (10 mg/kg/d) increased plasma aldosterone without affecting corticosterone or 11-deoxycorticosterone. In conclusion, the aldosterone synthase inhibitor, FAD286, lowers plasma aldosterone in obese ZDF rats, but not in obese db/db mice.

Adaptations in Basal and Hypothalamic-Pituitary-Adrenal-Activated Deoxycorticosterone Responses Following Ethanol Self-administration in Cynomolgus Monkeys.

Acute ethanol activates the hypothalamic–pituitary–adrenal (HPA) axis, while long-term exposure results in a blunted neuroendocrine state, particularly with regards to the primary endpoint, cortisol, the primary glucocorticoid produced in the adrenal cortex. However, it is unknown if this dampened neuroendocrine status also influences other adrenocortical steroids. Plasma concentration of the mineralocorticoid and neuroactive steroid precursor deoxycorticosterone (DOC) is altered by pharmacological challenges of the HPA axis in cynomolgus monkeys. The present study investigated HPA axis regulation of circulating DOC concentration over the course of ethanol (4% w/v) induction and self-administration in non-human primates (Macaca fasciculata, n = 10). Plasma DOC, measured by radioimmunoassay, was compared at baseline (ethanol naïve), during schedule-induced polydipsia, and following 6-months of 22 h/day access to ethanol and water. The schedule induction of ethanol drinking did not alter basal DOC levels but selectively dampened the DOC response to pharmacological challenges aimed at the anterior pituitary (ovine corticotrophin-releasing hormone) and adrenal gland (post-dexamethasone adrenocorticotropin hormone), while pharmacological inhibition of central opioid receptors with naloxone greatly enhanced the DOC response during induction. Following 6 months of ethanol self-administration, basal DOC levels were increased more than twofold, while responses to each of the challenges normalized somewhat but remained significantly different than baseline. These data show that HPA axis modulation of the neuroactive steroid precursor DOC is markedly altered by the schedule induction of ethanol drinking and long-term voluntary ethanol self-administration. The consequences of chronic ethanol consumption on HPA axis regulation of DOC point toward allostatic modification of hypothalamic and adrenal function.

Study of Aldosterone Synthase Inhibition as an Add‐On Therapy in Resistant Hypertension

Aldosterone inhibition with mineralcorticoid receptor antagonists (MRAs) is an effective treatment for resistant hypertension. Aldosterone synthase inhibitors (ASIs) are currently being investigated as a new therapeutic strategy to reduce aldosterone secretion from the adrenal gland. In this study, the efficacy and safety of the first-generation ASI LCI699 (0.25 mg twice daily, 1 mg 4 once daily, and 0.5 mg/1 mg twice daily) was compared with placebo and eplerenone (50 mg twice daily), in patients with resistant hypertension. Placebo-adjusted decreases in systolic blood pressure (BP) with LCI699 ranged from 2.6 mm Hg to 4.3 mm Hg at week 8; changes in diastolic BP ranged from +0.3 mm Hg to -1.2 mm Hg. However, reductions were smaller than observed with eplerenone 50 mg twice daily (9.9 mm Hg and 2.9 mm Hg for systolic and diastolic BP, respectively) and not statistically significant vs placebo. LCI699 suppressed plasma aldosterone levels in a dose-related manner with corresponding dose-dependent increases in plasma renin activity and plasma 11-deoxycorticosterone. LCI699 and eplerenone were well tolerated. These data demonstrate that aldosterone synthesis inhibition with LCI699 lowers BP modestly in patients with resistant hypertension. Aldosterone synthesis inhibition might offer an attractive adjunct to aldosterone receptor blockade, although the potential of a combination MRA/ASI has not yet been tested.

Genetic analysis of the neurosteroid deoxycorticosterone and its relation to alcohol phenotypes: identification of QTLs and downstream gene regulation.

BackgroundDeoxycorticosterone (DOC) is an endogenous neurosteroid found in brain and serum, precursor of the GABAergic neuroactive steroid (3α,5α)-3,21-dihydroxypregnan-20-one (tetrahydrodeoxycorticosterone, THDOC) and the glucocorticoid corticosterone. These steroids are elevated following stress or ethanol administration, contribute to ethanol sensitivity, and their elevation is blunted in ethanol dependence.Methodology/Principal FindingsTo systematically define the genetic basis, regulation, and behavioral significance of DOC levels in plasma and cerebral cortex we examined such levels across 47 young adult males from C57BL/6J (B6)×DBA/2J (D2) (BXD) mouse strains for quantitative trait loci (QTL) and bioinformatics analyses of behavior and gene regulation. Mice were injected with saline or 0.075 mg/kg dexamethasone sodium salt at 8:00 am and were sacrificed 6 hours later. DOC levels were measured by radioimmunoassay. Basal cerebral cortical DOC levels ranged between 1.4 and 12.2 ng/g (8.7-fold variation, p<0.0001) with a heritability of ∼0.37. Basal plasma DOC levels ranged between 2.8 and 12.1 ng/ml (4.3-fold variation, p<0.0001) with heritability of ∼0.32. QTLs for basal DOC levels were identified on chromosomes 4 (cerebral cortex) and 14 (plasma). Dexamethasone-induced changes in DOC levels showed a 4.4-fold variation in cerebral cortex and a 4.1-fold variation in plasma, but no QTLs were identified. DOC levels across BXD strains were further shown to be co-regulated with networks of genes linked to neuronal, immune, and endocrine function. DOC levels and its responses to dexamethasone were associated with several behavioral measures of ethanol sensitivity previously determined across the BXD strains by multiple laboratories.Conclusions/SignificanceBoth basal and dexamethasone-suppressed DOC levels are positively correlated with ethanol sensitivity suggesting that the neurosteroid DOC may be a putative biomarker of alcohol phenotypes. DOC levels were also strongly correlated with networks of genes associated with neuronal function, innate immune pathways, and steroid metabolism, likely linked to behavioral phenotypes.

Aldosterone Synthase Inhibition: A Promising Beginning

We report the first administration of an orally active aldosterone synthase inhibitor, LCI699, to 14 patients with primary aldosteronism. After a 2-week placebo run-in, patients received oral LCI699 (0.5 mg BID) for 2 weeks, LCI699 (1.0 mg BID) for 2 weeks, and placebo for 1 week. We assessed changes in hormone concentrations, plasma potassium levels, and 24-hour ambulatory systolic blood pressure and safety. The supine plasma aldosterone concentration decreased from 540 pmol/L (95% CI: 394 to 739 pmol/L) to 171 pmol/L (95% CI: 128 to 230 pmol/L) after 0.5 mg of LCI699 (–68%; P<0.0001) and to 133 pmol/L (95% CI: 100 to 177 pmol/L) after 1.0 mg of LCI699 (–75%; P<0.0001). Plasma 11-deoxycorticosterone concentrations increased by 710% after 0.5 mg of LCI699 (P<0.0001) and by 1427% after 1.0 mg of LCI699 (P<0.0001). The plasma potassium concentration increased from 3.27±0.31 to 4.03±0.33 mmol/L (P<0.0001) after only 1 week on 0.5 mg of LCI699. Twenty-four–hour ambulatory systolic blood pressure decreased by –4.1 mm Hg (95% CI: –8.1 to –0.1 mm Hg) after 4 weeks of treatment (P=0.046). Basal plasma cortisol concentrations remained unchanged,whereas plasma adrenocorticotropic hormone concentrations increased by 35% after 0.5 mg of LCI699 (P=0.08) and by 113% after 1.0 mg of LCI699 (P<0.0001), and the plasma cortisol response to an adrenocorticotropic hormone test was blunted. All of the variables except plasma 11-deoxycorticosterone concentration returned to initial levels after the placebo. LCI699 was well tolerated. In conclusion, the administration of LCI699, up to 1.0 mg BID, effectively and safely inhibits aldosterone synthase in patients with primary aldosteronism. This 4-week treatment corrected the hypokalemia and mildly decreased blood pressure. The effects on the glucocorticoid axis were consistent with a latent inhibition of cortisol synthesis.

Aldosterone Synthase Inhibition With LCI699

We report the first administration of an orally active aldosterone synthase inhibitor, LCI699, to 14 patients with primary aldosteronism. After a 2-week placebo run-in, patients received oral LCI699 (0.5 mg BID) for 2 weeks, LCI699 (1.0 mg BID) for 2 weeks, and placebo for 1 week. We assessed changes in hormone concentrations, plasma potassium levels, and 24-hour ambulatory systolic blood pressure and safety. The supine plasma aldosterone concentration decreased from 540 pmol/L (95% CI: 394 to 739 pmol/L) to 171 pmol/L (95% CI: 128 to 230 pmol/L) after 0.5 mg of LCI699 (-68%; P<0.0001) and to 133 pmol/L (95% CI: 100 to 177 pmol/L) after 1.0 mg of LCI699 (-75%; P<0.0001). Plasma 11-deoxycorticosterone concentrations increased by 710% after 0.5 mg of LCI699 (P<0.0001) and by 1427% after 1.0 mg of LCI699 (P<0.0001). The plasma potassium concentration increased from 3.27±0.31 to 4.03±0.33 mmol/L (P<0.0001) after only 1 week on 0.5 mg of LCI699. Twenty-four-hour ambulatory systolic blood pressure decreased by -4.1 mm Hg (95% CI: -8.1 to -0.1 mm Hg) after 4 weeks of treatment (P=0.046). Basal plasma cortisol concentrations remained unchanged, whereas plasma adrenocorticotropic hormone concentrations increased by 35% after 0.5 mg of LCI699 (P=0.08) and by 113% after 1.0 mg of LCI699 (P<0.0001), and the plasma cortisol response to an adrenocorticotropic hormone test was blunted. All of the variables except plasma 11-deoxycorticosterone concentration returned to initial levels after the placebo. LCI699 was well tolerated. In conclusion, the administration of LCI699, up to 1.0 mg BID, effectively and safely inhibits aldosterone synthase in patients with primary aldosteronism. This 4-week treatment corrected the hypokalemia and mildly decreased blood pressure. The effects on the glucocorticoid axis were consistent with a latent inhibition of cortisol synthesis.

Plasma 11-deoxycorticosterone (DOC) and mineralocorticoid receptor testicular expression during rainbow trout Oncorhynchus mykiss spermiation: implication with 17alpha, 20beta-dihydroxyprogesterone on the milt fluidity?

BackgroundIn rainbow trout (Oncorhynchus mykiss), the endocrine control of spermiation is not fully understood. Besides 11ketotestosterone (11KT) and 17alpha, 20beta-dihydroxyprogesterone (MIS), the potential physiological ligand of the mineralocorticoid receptor (MR) 11-deoxycorticosterone (DOC), is a credible candidate in O. mykiss spermiation regulation as spermiation is accompanied with changes in aqueous and ionic flows.MethodsIn this study, we investigated potential roles of DOC during spermiation 1) by describing changes in blood plasma DOC level, MR mRNA abundance during the reproductive cycle and MR localization in the reproductive tract 2) by investigating and comparing the effects of DOC (10 mg/kg) and MIS (5 mg/kg) supplementations on sperm parameters 3) by measuring the in vitro effect of DOC on testis MIS production.ResultsThe plasma concentration of DOC increased rapidly at the end of the reproductive cycle to reach levels that were 10–50 fold higher in mature males than in immature fish. MR mRNA relative abundance was lower in maturing testes when compared to immature testes, but increased rapidly during the spermiation period, immediately after the plasma rise in DOC. At this stage, immunohistochemistry localized MR protein to cells situated at the periphery of the seminiferous tubules and in the efferent ducts. Neither DOC nor MIS had significant effects on the mean sperm volume, although MIS treatment significantly increased the percentage of males producing milt. However, a significant reduction in the spermatocrit was observed when DOC and MIS were administrated together. Finally, we detected an inhibitory effect of DOC on testis MIS production in vitro.ConclusionThese results are in agreement with potential roles of DOC and MR during spermiation and support the hypothesis that DOC and MIS mechanisms of action are linked during this reproductive stage, maybe controlling milt fluidity. They also confirm that in O. mykiss MIS is involved in spermiation induction.

Systemic ethanol administration elevates deoxycorticosterone levels and chronic ethanol exposure attenuates this response

Systemic ethanol administration is known to elevate levels of the GABAergic neuroactive steroid 3α,21-dihydroxy-5α-pregnan-20-one (3α,5α-THDOC). 3α,5α-THDOC is synthesized from deoxycorticosterone (DOC) by metabolism in adrenals and brain. The present study investigated DOC levels in plasma and brain following ethanol administration to naïve and ethanol-exposed rats. Rats were administered ethanol (2 g/kg, i.p.) or saline and DOC levels were measured in plasma and brain regions by radioimmunoassay. Chronic ethanol-exposed rats were administered an ethanol challenge (2 g/kg, i.p.) following 15 days of ethanol liquid diet consumption. Ethanol administration markedly increased DOC levels in plasma, cerebral cortex, hippocampus, hypothalamus, cerebellum, and olfactory tubercle of naïve rats. Ethanol challenge produced an attenuated elevation of DOC in rat plasma and brain following chronic ethanol consumption for 2 weeks. These findings suggest that acute ethanol increases DOC levels in ethanol naïve rats and chronic ethanol consumption induces tolerance to ethanol-induced increases in DOC levels.

Adrenocortical carcinoma producing 11-deoxycorticosterone: A rare cause of mineralocorticoid hypertension

A 37-yr-old man presented with the classic signs of mineralocorticoid excess hypertension and hypokalemia. The cause was not aldosterone excess, but elevation of plasma 11-deoxycorticosterone (DOC). Computed tomography (CT) scans showed a large right adrenal mass without signs of metastatic disease. The tumor was removed by open laparotomy, and histology revealed an adrenocortical carcinoma. Two yr after diagnosis, the patient is in good general condition and there is no sign of recurrence or metastatic disease, despite the large tumor size. DOC producing adrenocortical carcinomas causing mineralocorticoid hypertension are very rare, so far only 10 cases have been described in the literature.

Molecular genetic study in two patients with congenital hypoaldosteronism (types I and II) in relation to previously published hormonal studies.

We performed a molecular genetic study in two patients with congenital hypoaldosteronism. An original study of these patients was published in this Journal in 1982. Both index cases, a girl (patient 1) and a boy (patient 2). presented with salt-wasting and failure to thrive in the neonatal period. Parents of patient 1 were not related, whereas the parents of patient 2 were cousins. Endocrine studies had shown a defect in 18-oxidation of 18-OH-corticosterone in patient 1 and a defect in the 18-hydroxylation of corticosterone in patient 2. Plasma aldosterone was decreased in both patients, whereas 18-OH-corticosterone was elevated in patient 1 and decreased in patient 2. Plasma corticosterone and 11-deoxycorticosterone were elevated in both patients, whereas cortisol and its precursors were in the normal range. According to the nomenclature proposed by Ulick, the defects are termed corticosterone methyl oxidase (CMO) deficiency type II in patient 1, and type I in patient 2 respectively. Genetic defects in the gene CYP11B2 encoding aldosterone synthase have been described in a few cases. In patient 1, we identified only one heterozygous amino acid substitution (V386A) in exon 7, which has no deleterious effect on the enzyme activity. In patient 2 and his older brother, we identified a homozygous single base exchange (G to T) in codon 255 (GAG), causing a premature stop codon E255X (TAG). The mutant enzyme has lost the five terminal exons containing the haem binding site, and is thus a loss of function enzyme. This is only the second report of a patient with CMO deficiency type II without a mutation in the exons and exon-intron boundaries, whereas the biochemical phenotype of the two brothers with CMO deficiency type I can be explained by the patient's genotype.

The preclinical pharmacology of "Arimidex" (anastrozole; ZD1033)--a potent, selective aromatase inhibitor.

Anastrozole is a comparatively simple, achiral benzyltriazole derivative, 2,2'-[5-(1H-1,2,4-triazol-1-ylmethyl)-1,3-phenylene]bis(2-++ +methylpropiononitrile), that inhibits human placental aromatase with an IC50 of 15 nM and elicits maximal activity in vivo in rats (inhibition of ovulation and androstenedione-induced uterine hypertrophy) and monkeys (lowering of plasma oestradiol) at 0.1 mg/kg p.o. At 30 times this dose, anastrozole does not elevate plasma 11-deoxycorticosterone in monkeys, and at 100 times this dose, does not affect plasma aldosterone levels or Na+/K+ excretion in rats, plasma K+ concentrations in dogs, or cause adrenal hypertrophy in rats or dogs. It therefore has no discernible effect on adrenocorticoid hormone synthesis in vivo at very large multiples of its maximally effective aromatase-inhibiting dose. At similar large multiples in rats it displays no oestrogenic, anti-oestrogenic, androgenic, anti-androgenic, progestogenic, glucocorticoid, antiglucocorticoid or mineralocorticoid activity. Anastrozole is thus a potent and highly selective aromatase inhibitor, with no intrinsic hormonal activities--a pharmacological profile particularly suitable for the treatment of breast cancer.

Chronic mineralocorticoid excess and cardiovascular remodeling

Chronic mineralocorticoid (MC) excess, whether due to elevated plasma aldosterone (ALDO) or deoxycorticosterone (DOC), is associated with a perivascular fibrosis of systemic and coronary arterioles. This remodeling of resistance vessels contributes to the appearance of hypertension. Chronic MC excess is also accompanied by cardiac myocyte necrosis, secondary to myocardial potassium depletion, and a subsequent reparative fibrosis that appears in the normotensive, nonhypertrophied right and hypertensive, hypertrophied left ventricles. Fibrosis contributes to the appearance of ventricular arrhythmias and dysfunction. Herein, clinical and experimental evidence linking chronic, inappropriate (relative to dietary sodium) elevations in circulating ALDO and DOC with these reactive and reparative forms of fibrous tissue formation in the heart and other tissues is presented.

Salt Sensitivity of Blood Pressure in Patients With 17α-Hydroxylase Deficiency

To clarify the salt sensitivity of blood pressure in 17 alpha-hydroxylase deficiency (17 alpha-HD), a mineralocorticoid-induced hypertension, we examined the responses of blood pressure to salt loading (250 mEq/day for 6 days) after salt restriction (25 mEq/day for 3 days) in two 17 alpha-HD patients who had markedly high plasma deoxycorticosterone (DOC) (5.27 and 6.59 ng/mL; normal, 0.08 to 0.28) and corticosterone (B) (93 and 357 ng/mL; normal, 0.35 to 8.42). In case 1, moreover, the same study was repeated when plasma DOC and B restored to almost normal with the dexamethasone treatment (1 mg/day) (0.34 and 0.45 ng/mL). Salt loading elevated mean blood pressure markedly in both patients (14% and 20%), associated with cumulative sodium retention and body weight gain. Hemodynamic study showed marked increases in cardiac output (25% and 69%), but only slight decreases in systemic vascular resistance with salt loading. On the other hand, the treatment with dexamethasone could attenuate the salt-induced increase in blood pressure (2%), accompanied by lesser sodium retention, body weight gain, and elevation of cardiac output (7%) in case 1. The slope of the renal function curve for sodium excretion was decreased in these patients, and was restored toward normal by dexamethasone in case 1. We conclude that the patients with 17 alpha-HD showed salt-sensitive hypertension due to excessive DOC and B, through the impaired renal function for sodium excretion, disproportionate increase in cardiac output, and inadequate vasodilation.

Elevated plasma 19‐hydroxyandrostenedione levels in Cushing's disease: stimulation with ACTH and inhibition with metyrapone

The regulation of 19-hydroxyandrostenedione secretion has been suggested to be under the control of both the ACTH-adrenal axis and renin-angiotensin system. We undertook the present study to evaluate the effect of the chronic excess of ACTH, or the short-term excess of ACTH due to metyrapone, on 19-hydroxyandrostenedione secretion in patients with Cushing's disease. We measured plasma 19-hydroxyandrostenedione levels simultaneously with plasma delta 4-androstenedione, corticosterone, 11-deoxycorticosterone, aldosterone and cortisol levels after HPLC separation in 13 patients with Cushing's disease under basal conditions and during a dexamethasone suppression test or metyrapone test. Seven patients with Cushing's syndrome due to adrenal adenoma were used for comparison. The basal levels of 19-hydroxyandrostenedione in Cushing's disease were elevated (mean +/- SD; 323 +/- 193 pmol/l, n = 13), while those in Cushing's syndrome due to adrenal adenoma were low (92 +/- 24 pmol/l, n = 7), compared to those in normal subjects (117 +/- 33 pmol/l, n = 54). The basal levels of delta 4-androstenedione were mildly elevated in Cushing's disease (9.0 +/- 6.5 vs 3.6 +/- 2.6 nmol/l of normal subjects) but not in Cushing's syndrome due to adrenal adenoma (3.1 +/- 3.0 nmol/l). In the overnight 8 mg dexamethasone suppression test in Cushing's disease (n = 12), plasma levels of 19-hydroxyandrostenedione and delta 4-androstenedione decreased from 277 +/- 172 to 156 +/- 99 pmol/l and from 9.2 +/- 6.8 to 4.7 +/- 3.4 nmol/l, respectively, whereas the overnight 1 mg dexamethasone suppression test did not induce significant changes. Metyrapone administration in Cushing's disease (n = 9) increased plasma delta 4-androstenedione level from 9.5 +/- 6.7 to 47.2 +/- 28.1 nmol/l, but decreased plasma 19-hydroxyandrostenedione level from 301 +/- 196 to 196 +/- 105 pmol/l. These data indicate that plasma levels of 19-hydroxyandrostenedione in patients with Cushing's disease are elevated due to chronic ACTH excess, and that metyrapone can inhibit 19-hydroxylation in humans.

Inappropriate Elevation of the Aldosterone/Plasma Renin Activity Ratio in Hypertensive Patients with Increases of 11-Deoxycorticosterone and 18-Hydroxy-ll-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.