Mineralocorticoid Levels Research Articles

The brain-gut axis of fish: Rainbow trout with low and high cortisol response show innate differences in intestinal integrity and brain gene expression

In fish, the stress hormone cortisol is released through the action of the hypothalamic pituitary interrenal axis (HPI-axis). The reactivity of this axis differs between individuals and previous studies have linked this to different behavioural characteristics and stress coping styles. In the current study, low and high responding (LR and HR) rainbow trout in terms of cortisol release during stress were identified, using a repeated confinements stress test. The expression of stress related genes in the forebrain and the integrity of the stress sensitive primary barrier of the intestine was examined. The HR trout displayed higher expression levels of mineralocorticoid and serotonergic receptors and serotonergic re-uptake pumps in the telencephalon during both basal and stressed conditions. This confirms that HPI-axis reactivity is linked also to other neuronal behavioural modulators, as both the serotonergic and the corticoid system in the telencephalon are involved in behavioural reactivity and cognitive processes. Involvement of the HPI-axis in the brain-gut-axis was also found. LR trout displayed a lower integrity in the primary barrier of the intestine during basal conditions compared to the HR trout. However, following stress exposure, LR trout showed an unexpected increase in intestinal integrity whereas the HR trout instead suffered a reduction. This could make the LR individuals more susceptible to pathogens during basal conditions where instead HR individuals would be more vulnerable during stressed conditions. We hypothesize that these barrier differences are caused by regulation/effects on tight junction proteins possibly controlled by secondary effects of cortisol on the intestinal immune barrier or differences in parasympathetic reactivity.

A Liquid Chromatography/Tandem Mass Spectometry Profile of 16 Serum Steroids, Including 21-Deoxycortisol and 21-Deoxycorticosterone, for Management of Congenital Adrenal Hyperplasia.

Context:Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency (CAH21) is most often diagnosed by newborn screening. The classic parameter studied is 17-hydroxy-progesterone, but the positive predictive value for the diagnosis of CAH is low in full-term newborns and even lower in preterm newborns.Objective:To evaluate the diagnostic utility of simultaneously quantifying a large number of steroids by using liquid chromatography/tandem mass spectrometry (LC-MS/MS) from a small serum volume in patients with CAH, particularly during the neonatal period.Setting and participants:LC-MS/MS was applied to sera from patients with CAH who had a classic form (n = 48) and rare forms (n = 2) of 21-hydroxylase deficiency, normal preterm (n = 10) and normal full-term (n = 20) neonates, and young patients without CAH (non-CAH; n = 149) but with various other diseases (delayed or advanced puberty, hirsutism, pubarche, adrenarche, simple growth retardation).Methods:Sixteen steroids (glucocorticoids, mineralocorticoids, androgens, Δ5-steroids) were analyzed in 150 µL of serum by LC-MS/MS.Results:An LC-MS/MS serum steroid profile was developed and validated to provide a reliable etiologic diagnosis of CAH. The serum levels of 17OH-progesterone and 21 deoxycortisol in non-CAH are reported, along with the rarely assayed 21-deoxycorticorticosterone and 11β hydroxy Δ4-androstenedione, which will aid in the diagnosis of CAH21. In addition, serum levels of mineralocorticoids, androgens, and Δ5-steroids allowed investigation of other forms of CAH.Conclusion:This steroid LC-MS/MS approach on a small serum volume is well suited for pediatrics, particularly neonatal medical practice, to aid in the diagnosis and monitoring of various forms of CAH.

Stress-Kinase Regulation of TASK-1 and TASK-3

Background/Aims: TASK channels belong to the two-pore-domain potassium (K_2P) channel family. TASK-1 is discussed to contribute to chronic atrial fibrillation (AFib) and has been together with uncoupling protein 1 found as a marker protein of brown adipose tissue (BAT) fat. In addition, TASK-1 was linked in a genome-wide association study to an increased body mass index. A recent study showed that TASK-1 inhibition is causing obesity in mice by a BAT whitening and that these effects are linked to the mineralocorticoid receptor pathway, albeit the mechanism remained elusive. Therefore, we aimed to probe whether K_2P channels are regulated by serum- and glucocorticoid-inducible kinases (SGKs) which are known to modify many cellular functions by modulating ion channels. Methods: To this end we used functional co-expression studies and chemiluminescence-assays in Xenopus oocytes, together with fluorescence imaging and quantitative PCR experiments. Results: SGKs and proteinkinase B (PKB) induced a strong, dose- and time-dependent current reduction of TASK-1 and TASK-3. SGK co-expression reduced the surface expression of TASK-1/3, leading to a predominant localization of the channels into late endosomes. The down regulation of TASK-3 channels was abrogated by the dynamin inhibitor dynasore, confirming a role of SGKs in TASK-1/3 channel endocytosis. Conclusion: Stress-mediated changes in SGK expression pattern or activation is likely to alter TASK-1/3 expression at the surface membrane. The observed TASK-1 regulation might contribute to the pathogenesis of chronic AFib and provide a mechanistic link between increased mineralocorticoid levels and TASK-1 reduction, both linked to BAT whitening.

Diagnosis and treatment of hyperkalemia.

Hyperkalemia results either from the shift of potassium out of cells or from abnormal renal potassium excretion. Cell shift leads to transient increases in the plasma potassium concentration, whereas decreased renal excretion of potassium leads to sustained hyperkalemia. Impairments in renal potassium excretion can be the result of reduced sodium delivery to the distal nephron, decreased mineralocorticoid level or activity, or abnormalities in the cortical collecting duct. In some instances, all 3 of these perturbations are present. Excessive intake of potassium can cause hyperkalemia but usually in the setting of impaired renal function. We discuss the clinical manifestations of hyperkalemia and outline an approach to its diagnosis and treatment.

Maternal depressive symptoms throughout pregnancy are associated with increased placental glucocorticoid sensitivity.

Maternal prenatal depression predicts post-partum depression and increases risk of prematurity and low birth weight. These effects may be mediated by altered placental function. We hypothesized that placental function would be influenced by the gestational week of experiencing depressive symptoms and aimed to examine associations between maternal depressive symptoms during pregnancy and placental expression of genes involved in glucocorticoid and serotonin transfer between mother and fetus. We studied women participating in a prospective pregnancy cohort: the Prediction and Prevention of Preeclampsia (PREDO) Study, Helsinki, Finland. Maternal depressive symptoms were assessed at 2-week intervals throughout pregnancy in 56 healthy women with singleton, term pregnancies. Messenger ribonucleic acid (mRNA) levels of glucocorticoid (GR) and mineralocorticoid (MR) receptors and serotonin transporter (SLC6A4), 11β-hydroxysteroid dehydrogenase type 1 (HSD1) and 2 (HSD2) were quantified in placental biopsies. In adjusted analyses women who reported higher depressive symptoms across the whole pregnancy had higher mRNA levels of GR [effect size 0.31 s.d. units, 95% confidence interval (CI) 0.01-0.60, p=0.042] and MR (effect size 0.34 s.d. units, 95% CI 0.01-0.68, p=0.047). These effects were significant for symptoms experienced in the third trimester of pregnancy for GR; findings for MR were also significant for symptoms experienced in the second trimester. GR and MR mRNA levels increased linearly by having the trimester-specific depressive symptoms scores 0, 1 or 2-3 times above the clinical cut-off for depression (p=0.003, p=0.049, respectively, and p=0.004, p=0.15 in adjusted analyses). Our findings offer potential gestational-age-specific mechanisms linking maternal depressive symptoms during pregnancy via placental biology. Future studies will test whether these also link with adverse offspring outcomes.

Behavioral and molecular alterations in mice resulting from chronic treatment with dexamethasone: Relevance to depression

Chronic stress, the administration of glucocorticoids and the prolonged activation of glucocorticoid receptors (GRs) are reported to induce affective changes in humans and rodents that resemble a depressive state. However, data concerning the behavioral and molecular effects of the selective activation of specific GRs are limited, and the conclusions derived remain debatable. In this study, our goal was to investigate the behavioral and molecular changes following the prolonged activation of GRs in mice via exposure to the specific agonist dexamethasone (DEX). C57BL/6J mice were injected daily with DEX (4mg/kg, i.p.) or saline, and the behavior of the animals was assessed in the following paradigms: the forced swimming test (FST), the light–dark box test, the saccharin preference test and activity boxes. The mRNA expression levels of the corticosteroid receptors mineralocorticoid (MR, Nr3c2) and glucocorticoid (GR, Nr3c1), selected stress dependent genes and glial markers were analyzed in the prefrontal cortex, hippocampus and striatum. DEX-treated mice exhibited a variety of depression-like behaviors: increased time of immobility in the FST, a reduced preference for saccharin consumption and increased anxiety-like behavior. Behavioral alterations were accompanied by a decrease in the mRNA expression of GR and the increased expression of Fkbp5 and Sgk1 in the prefrontal cortex, hippocampus and striatum of DEX-treated mice. Furthermore, our results indicate a decrease in the mRNA expression of glutamate aspartate transporter (GLAST, Slc1a3), an astroglial cell marker, in the hippocampus and prefrontal cortex. These results demonstrate that the prolonged activation of GR receptors induced a depression-like state in mice, activated stress-related genes and induced a decrease in the mRNA expression of GLAST, an astroglial marker, in the prefrontal cortex and hippocampus. Together, the results reported here challenge several hypotheses concerning the role of GRs in the development of behavioral and molecular alterations relevant to stress-related disorders, such as depression, under the same experimental conditions.

Plasma steroid profiling and response to trophins to illustrate intra-adrenal dynamics.

The importance of corticosteroids in cardiovascular and other chronic disease is recognised. In addition, plasma steroid precursor-to-product ratios are useful and convenient indirect indicators of efficiency of key steroidogenic enzymes (aldosterone synthase, 11β-hydroxylase and 17α-hydroxylase). The use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) has enabled measurement of numerous corticosteroid compounds simultaneously. However, normal responses to trophins and variation in salt intake are not well described. This study examined these parameters in a large group of healthy volunteers. Sixty normotensive volunteers were recruited and underwent infusion of angiotensin II (AngII) and ACTH, following low- and high-salt diet. Measurement of plasma steroids at baseline and 30 min after infusion of trophin was carried out by LC-MS. As expected, plasma mineralocorticoid levels increased in response to salt restriction and were suppressed with salt loading; ACTH infusion increased all corticosteroids, while AngII increased mineralocorticoids and suppressed glucocorticoid production. ACTH increased S:F but decreased DOC:B, thus the S:F ratio is a more appropriate index of 11β-hydroxylase efficiency. The B:F ratio increased following ACTH treatment and salt restriction. A larger proportion of plasma B than generally accepted may be derived from the zona glomerulosa and this ratio may be most informative of 17α-hydroxylase activity in salt-replete subjects. Although DOC:aldosterone, B:aldosterone and 18-hydroxyB:aldosterone should provide indices of aldosterone synthase efficiency, responses of individual compounds to trophins suggest that none of them accurately reflect this. Based on these data, aldosterone synthase activity is most accurately reflected by aldosterone concentration alone.

Structures of Human Steroidogenic Cytochrome P450 17A1 with Substrates

The human cytochrome P450 17A1 (CYP17A1) enzyme operates at a key juncture of human steroidogenesis, controlling the levels of mineralocorticoids influencing blood pressure, glucocorticoids involved in immune and stress responses, and androgens and estrogens involved in development and homeostasis of reproductive tissues. Understanding CYP17A1 multifunctional biochemistry is thus integral to treating prostate and breast cancer, subfertility, blood pressure, and other diseases. CYP17A1 structures with all four physiologically relevant steroid substrates suggest answers to four fundamental aspects of CYP17A1 function. First, all substrates bind in a similar overall orientation, rising ∼60° with respect to the heme. Second, both hydroxylase substrates pregnenolone and progesterone hydrogen bond to Asn(202) in orientations consistent with production of 17α-hydroxy major metabolites, but functional and structural evidence for an A105L mutation suggests that a minor conformation may yield the minor 16α-hydroxyprogesterone metabolite. Third, substrate specificity of the subsequent 17,20-lyase reaction may be explained by variation in substrate height above the heme. Although 17α-hydroxyprogesterone is only observed farther from the catalytic iron, 17α-hydroxypregnenolone is also observed closer to the heme. In conjunction with spectroscopic evidence, this suggests that only 17α-hydroxypregnenolone approaches and interacts with the proximal oxygen of the catalytic iron-peroxy intermediate, yielding efficient production of dehydroepiandrosterone as the key intermediate in human testosterone and estrogen synthesis. Fourth, differential positioning of 17α-hydroxypregnenolone offers a mechanism whereby allosteric binding of cytochrome b5 might selectively enhance the lyase reaction. In aggregate, these structures provide a structural basis for understanding multiple key reactions at the heart of human steroidogenesis.

Inhibition of the androgen receptor by mineralocorticoids at levels physiologically achieved in serum in patients treated with abiraterone acetate.

Abiraterone acetate (AA), a highly potent CYP17A1 inhibitor, has demonstrated marked clinical benefit in patients with metastatic castration-resistant prostate cancer (CRPC). Phase I trials of AA without prednisone showed significant elevation of serum mineralocorticoid concentrations. The aim of this study was to elucidate the biological significance of elevated mineralocorticoid levels on androgen receptor (AR) activity in prostate cancer (PC) cells. Fluorescence resonance energy transfer (FRET) assay was used to assess the effect of mineralocorticoids on androgen-induced conformational change of the AR. LAPC4, LNCaP and LN-AR cells that were cultured and treated with androgens were exposed to mineralocorticoids at varying concentrations, including levels measured in the serum of AA-treated patients in a phase I trial. AR-dependent transcriptional activity and cell growth were measured in these cell lines to determine the biological impact of mineralocorticoids on PC cells. Corticosterone (CS) and deoxycorticosterone (DOC) inhibited androgen-induced conformational change of the AR in the FRET assay. CS inhibited AR-dependent transcriptional activity and cell growth at concentrations comparable to those measured in the serum of AA-treated patients. DOC inhibited AR transcriptional activity and cell growth at 10-fold greater concentrations than measured in the serum of AA-treated patients. Mineralocorticoids directly inhibit androgen-induced conformational change of the AR. CS inhibits AR transcriptional activity and PC cell growth at concentrations found in the serum of patients treated with AA. Further investigation of the potential therapeutic implications of mineralocorticoids in AA-treated CRPC patients is warranted.

Effects of the cholesteryl ester transfer protein inhibitor evacetrapib on lipoproteins, apolipoproteins and 24-h ambulatory blood pressure in healthy adults.

ObjectivesWe investigated the safety, tolerability, pharmacokinetics and pharmacodynamics of evacetrapib.MethodsHealthy volunteers received multiple daily doses of evacetrapib (10–600 mg) administered for up to 15 days in a placebo-controlled study.Key findingsMean peak plasma concentrations of evacetrapib occurred at 4–6 h and terminal half-life ranged 24–44 h. Steady state was achieved at approximately 10 days; all subjects had undetectable levels of evacetrapib 3 weeks after their last dose. The trough inhibition of cholesteryl ester transfer protein (CETP) activity was 65 and 84% at 100 and 300 mg, respectively. At the highest dose (600 mg), evacetrapib significantly inhibited CETP activity (91%), increased HDL-C (87%) and apo AI (42%), and decreased LDL-C (29%) and apo B (26%) relative to placebo. For the highest dose tested, levels of evacetrapib, CETP activity, CETP mass, HDL-C and LDL-C returned to levels at or near baseline after a 2-week washout period. Evacetrapib at the highest dose tested did not produce any significant effect on 24-h ambulatory systolic or diastolic blood pressure.ConclusionsMultiple doses of evacetrapib potently inhibited CETP activity, leading to substantial elevations in HDL-C and lowering of LDL-C. Evacetrapib was devoid of clinically relevant effects on blood pressure and mineralocorticoid levels.

Polyglandular autoimmune syndrome type 2: diagnosed in the intensive care unit

Polyglandular autoimmune syndrome type 2 is a rare syndrome that commonly has the constellation of three diseases: diabetes mellitus type 1, hypothyroidism and adrenal insufficiency. Owing to the diabetes mellitus type 1, patients require life-long insulin therapy and blood glucose levels need to be monitored. They are at risk for chronic complications of diabetes such as neuropathy, nephropathy and retinopathy. More acutely, due to fluctuations in blood glucose levels, they are at risk for hypoglycemia with neuroglycopenic symptoms and ketoacidosis. Hypothyroidism is diagnosed by measuring the thyroid hormone levels and if inappropriately low is treated with replacement therapy. Patients with adrenal insufficiency experience symptoms due to low glucocorticoid and mineralocorticoid levels in the body, due to decreased or absent production. We present a case in which a patient presented with a picture of diabetic ketoacidosis was found to have hypothyroidism in her medical history and was diagnosed with adrenal insufficiency in the intensive care unit (ICU), later confirmed as an outpatient to be permanent. Based on the three diagnoses it was concluded that she has polyglandular autoimmune syndrome type 2.

Plasma renin activity profile of patients with congenital adrenal hyperplasia in Semarang, Indonesia: a preliminary study

Congenital Adrenal Hyperplasia (CAH) is an adrenal disorders due to impaired activity of one of the enzymes required for cortisol and aldosterone biosynthesis. One of the subtypes of CAH is the salt-wasting (SW) form which there is a renal salt loss due to aldosterone deficiency. Plasma Renin Activity (PRA) is the main index used to evaluate the mineralocorticoid control in CAH. PRA testing is almost very rare done for the CAH patients due to high cost, sophisticated laboratory is not available in all region and no compulsary health insurance in Indonesia. The objective of this research was to describe PRA level in patient with Congenital Adrenal Hyperplasia. This study is a part of CAH cohort study in Center for Biomedical Research (CEBIOR), Semarang, Indonesia. Eighteen patients diagnosed as CAH were drawned blood samples for hormonal test, including 17 OHP, Plasma Renin Activity, Cortisol, and Electrolytes. Clinical history and physical examination was performed to each patients. All 18 patients (17 female and 1 male) have high 17-OHP level and normal electrolites levels, but only 14 patients have PRA data. Four patients did not show their PRA level due to fail in too much blood collection. Out of 14 patient, four patients which had history of SW have very high PRA level, while six patients have PRA level more than normal without history of salt wasting. The mean of PRA level in patients with history of SW (47.72 (SD 18.63)) are higher than the patient without history of SW (13.97 (SD 13.3)). This study suggest that PRA level might be useful for evaluating mineralocorticoid level in CAH. It is proposed to the government to subsidize and provide PRA and other hormonal testing for CAH in many regions with affordable cost.

Endocannabinoid Receptor Deficiency Affects Maternal Care and Alters the Dam's Hippocampal Oxytocin Receptor and Brain‐Derived Neurotrophic Factor Expression

Maternal care is the newborn's first experience of social interaction, and this influences infant survival, development and social competences throughout life. We recently found that postpartum blocking of the endocannabinoid receptor-1 (CB1R) altered maternal behaviour. In the present study, maternal care was assessed by the time taken to retrieve pups, pups' ultrasonic vocalisations (USVs) and pup body weight, comparing CB1R deleted (CB1R KO) versus wild-type (WT) mice. After culling on postpartum day 8, hippocampal expression of oxytocin receptor (OXTR), brain-derived neurotrophic factor (BDNF) and stress-mediating factors were evaluated in CB1R KO and WT dams. Comparisons were also performed with nulliparous (NP) CB1R KO and WT mice. Compared to WT, CB1R KO dams were slower to retrieve their pups. Although the body weight of the KO pups did not differ from the weight of WT pups, they emitted fewer USVs. This impairment of the dam-pup relationship correlated with a significant reduction of OXTR mRNA and protein levels among CB1R KO dams compared to WT dams. Furthermore, WT dams exhibited elevated OXTR mRNA expression, as well as increased levels of mineralocorticoid and glucocorticoid receptors, compared to WT NP mice. By contrast, CB1R KO dams showed no such elevation of OXTR expression, alongside lower BDNF and mineralocorticoid receptors, as well as elevated corticotrophin-releasing hormone mRNA levels, when compared to CB1R KO NP. Thus, it appears that the disruption of endocannabinoid signalling by CB1R deletion alters expression of the OXTR, apparently leading to deleterious effects upon maternal behaviour.

Comparison of Stress-Induced Changes in Adults and Pups: Is Aldosterone the Main Adrenocortical Stress Hormone during the Perinatal Period in Rats?

Positive developmental impact of low stress-induced glucocorticoid levels in early development has been recognized for a long time, while possible involvement of mineralocorticoids in the stress response during the perinatal period has been neglected. The present study aimed at verifying the hypothesis that balance between stress-induced glucocorticoid and mineralocorticoid levels is changing during postnatal development. Hormone responses to two different stressors (insulin-induced hypoglycaemia and immune challenge induced by bacterial lipopolysaccharid) measured in 10-day-old rats were compared to those in adults. In pups corticosterone responses to both stressors were significantly lower than in adults, which corresponded well with the stress hyporesponsive period. Importantly, stress-induced elevations in aldosterone concentration were significantly higher in pups compared both to corticosterone elevations and to those in adulthood with comparable adrenocorticotropin concentrations in the two age groups. Greater importance of mineralocorticoids compared to glucocorticoids in postnatal period is further supported by changes in gene expression and protein levels of gluco- (GR) and mineralocorticoid receptors (MR) and selected enzymes measured by quantitative PCR and immunohystochemistry in the hypothalamus, hippocampus, prefrontal cortex, liver and kidney. Gene expression of 11beta-hydroxysteroid dehydrogenase 2 (11β-HSD2), an enzyme enabling preferential effects of aldosterone on mineralocorticoid receptors, was higher in 10-day-old pups compared to adult animals. On the contrary, the expression and protein levels of GR, MR and 11β-HSD1 were decreased. Presented results clearly show higher stress-induced release of aldosterone in pups compared to adults and strongly suggest greater importance of mineralocorticoids compared to glucocorticoids in stress during the postnatal period.

Blood pressure response to angiotensin II is enhanced in obese Zucker rats and is attributed to an aldosterone‐dependent mechanism

Plasma aldosterone levels correlate positively with obesity, suggesting a link between the hypertension associated with obesity and increased mineralocorticoid levels. We tested the hypothesis that aldosterone is involved in the BP response to angiotensin II (AngII) in obese rats. Lean (LZR) and obese (OZR) Zucker rats were treated with AngII (9 µg·h(-1) ; 4 weeks), and BP and plasma AngII and aldosterone were determined. Chronic AngII increased the BP in OZR markedly more so than in LZR. Plasma AngII levels in LZR and OZR were similar after AngII treatment. The AngII stimulated a rise in plasma aldosterone that was sixfold more in OZR than in LZR. The thickness of the zona glomerulosa of the adrenal glands was selectively increased by AngII in OZR. Adrenal mRNA levels of CYP11B2 aldosterone synthase and the AT(1B) receptor were selectively increased in AngII-treated OZR. The BP response to chronic AngII stimulation was diminished in OZR after adrenalectomy when plasma aldosterone was absent. Acute bolus injections of AngII did not increase the BP response or aldosterone release in OZR. The AngII-induced BP response is enhanced in obesity and this is associated with a specific increase in circulating aldosterone. Due to the AngII-induced growth of the zona glomerulosa in OZR, the AT(1B) receptors and aldosterone synthase may be selectively enhanced in obesity under concomitant AngII stimulation, increasing the adrenal synthesis of aldosterone. Our results confirm functionally that aldosterone plays a major role in obesity-related hypertension.

Different Polymorphisms of the Mineralocorticoid Receptor Gene Are Associated with either Glucocorticoid or Mineralocorticoid Levels in Hypertension

Both aldosterone and cortisol can activate the mineralocorticoid receptor (MR). Polymorphisms in the MR gene have been inconsistently shown to be associated with risk of hypertension and aldosterone and cortisol levels. The purpose of this project was to investigate the association of MR gene variants with serum aldosterone and a previously identified hypertension subgroup with higher urinary free cortisol (UFC) levels (high-mode UFC) in a rigorously phenotyped Caucasian hypertensive cohort. A haplotype-based tagging single nucleotide polymorphism (htSNP) association study was conducted in the HyperPATH cohort of 570 hypertensive Caucasian subjects on a salt-controlled diet. Haplotypes generated from 74 htSNP representing the common genetic variations of the entire MR gene were analyzed by comparing high- vs. normal-mode UFC groups and the association with serum aldosterone levels. Of the observed 20 haplotype blocks, there were three main linkage disequilibrium (LD) regions with high recombination rates between adjacent regions. Overlaying gene structure on this LD map revealed that block 1-8 corresponded to exon 5-9 [ligand binding domain (LBD)], blocks 9-18 to exon 3-4 [DNA binding domain (DBD)], and block 19-20 to exon 1-2 (N-terminal domain). Haplotype association results showed that DBD-aligned LD blocks were associated with high-mode UFC status (global P values, 0.0004 to 0.05). The LBD-aligned LD blocks showed significant associations with serum aldosterone levels. These findings imply that there may be differential functional importance of the DBD and LBD of the MR in the regulation of glucocorticoid and aldosterone levels in hypertensive subjects.

Abiraterone acetate: a novel therapeutic option in hormone-refractory prostate cancer

Until recently, only therapy with docetaxel and prednisone has been shown to prolong survival in men with hormonorefractory metastatic prostate cancer. With approvals of sipuleucel-T, cabazitaxel, and abiraterone acetate, all based on improvement in overall survival, the scenary for management of men with metastatic prostate cancer has dramatically changed. Abiraterone acetate was developed to specifically inhibit cytochrome P450 (CYP)17A1, which is an essential enzyme in the biosynthesis of testosterone. In the phase III, the trial treatment with abiraterone acetate plus prednisone prolongs overall survival relative to prednisone alone in patients with metastatic castration-resistant prostate cancer who have disease progression after treatment with docetaxel and associated with an acceptable tolerability profile, which was generally similar to that of the placebo plus prednisone group. However, adverse events resulting from elevated mineralocorticoid levels because of CYP17A1 inhibition, fluid retention and oedema, hypokalaemia, hypertension occurred in significantly more in abiraterone acetate plus prednisone than in placebo plus prednisone.

Familial glucocorticoid deficiency presenting with generalized hyperpigmentation in adolescence. Report of three siblings

Background:Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disorder characterized by glucocorticoid deficiency, high ACTH levels and normal mineralocorticoid levels. FGD is caused due to defects in adrenocorticotropic hormone (ACTH) signaling. The defect can be caused by mutations in genes encoding the ACTH receptor (melanocortin 2 receptor) or its accessory protein.Patients:Here we report three siblings with FGD. The second in order of siblings presented at an age of 15 years with history of diffuse hyperpigmentation since childhood. Their parents were non consanguineous. The patients were hyperpigmented and taller compared with their parents. None of the siblings had ambiguous genitalia or neurological abnormalities. There was no history of tuberculosis in the family. Biochemical investigations revealed low serum cortisol (<1 μg/dl) and elevated plasma ACTH (>1250 pg/ml). Serum electrolytes, aldosterone, and plasma renin activity was normal. Based on the above mentioned data, a provisional diagnosis of FGD was made after ruling out the common causes of glucocorticoid deficiency.Conclusion:FGD is a rare autosomal recessive disorder which causes isolated glucocorticoid deficiency. Unawareness about the condition may lead to delayed diagnosis and treatment, which are associated with high rates of morbidity and mortality. Once a diagnosis is made it is easily treatable.

Abiraterone Acetate

Oral abiraterone acetate, in combination with prednisone/prednisolone, is used to treat patients with metastatic castration-resistant prostate cancer (CRPC) who have previously received docetaxel-containing chemotherapy. Abiraterone acetate was developed to specifically inhibit cytochrome P450 (CYP)17A1, which is an essential enzyme in the biosynthesis of testosterone. In a pivotal phase III trial in patients with metastatic CRPC who have previously received docetaxel-containing chemotherapy, abiraterone acetate 1000 mg once daily plus prednisone 5 mg twice daily significantly prolonged overall survival compared with placebo plus prednisone. In this trial, abiraterone acetate plus prednisone was significantly more effective than placebo plus prednisone in prolonging the time to prostate-specific antigen (PSA) progression and in prolonging progression-free survival. Significantly more abiraterone acetate plus prednisone recipients than placebo plus prednisone recipients were considered to be responders, when assessed by PSA levels or radiographic imaging. Treatment with abiraterone acetate plus prednisone in the phase III trial was associated with an acceptable tolerability profile, which was generally similar to that of the placebo plus prednisone group. However, adverse events of special interest (e.g. cardiac disorders and liver-function test abnormalities and adverse events resulting from elevated mineralocorticoid levels because of CYP17A1 inhibition [i.e. fluid retention and oedema, hypokalaemia, hypertension]) occurred in significantly more abiraterone acetate plus prednisone than in placebo plus prednisone recipients.

Q&amp;A: Primary generalized glucocorticoid resistance

What biological processes underlie this “resistance” to cortisol? Because this resistance includes the hypothalamicpituitary-adrenal (HPA) axis negative feedback regulatory centers in the brain and pituitary gland, this axis is activated to “overcome” or compensate for the glucocorticoid action defect (Figure 1). The production of hypothalamic corticotropin-releasing hormone (CRH), arginine-vasopressin (AVP) and pituitary adrenocorticotropic hormone (ACTH) increase and the adrenal cortices hyperfunction, secreting large amounts of cortisol, adrenal steroid precursors and adrenal androgens. The adrenal steroid precursors include deoxy-corticosterone and corticosterone, both of which, as well as cortisol, have sodium-retaining activity through the mineralocorticoid receptor, which is normal in patients with cortisol resistance. Thus, the patient tissues are exposed to elevated levels of adrenal androgens and mineralocorticoids, which result in manifestations of hyperandrogenism and hypermineralocorticoidism.