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Publication
Journal: Psychoneuroendocrinology
December/8/2011
Abstract
Molecular and behavioural evidence points to an association between sex-steroid hormones and autism spectrum conditions (ASC) and/or autistic traits. Prenatal androgen levels are associated with autistic traits, and several genes involved in steroidogenesis are associated with autism, Asperger Syndrome and/or autistic traits. Furthermore, higher rates of androgen-related conditions (such as Polycystic Ovary Syndrome, hirsutism, acne and hormone-related cancers) are reported in women with autism spectrum conditions. A key question therefore is if serum levels of gonadal and adrenal sex-steroids (particularly testosterone, estradiol, dehydroepiandrosterone sulfate and androstenedione) are elevated in individuals with ASC. This was tested in a total sample of n=166 participants. The final eligible sample for hormone analysis comprised n=128 participants, n=58 of whom had a diagnosis of Asperger Syndrome or high functioning autism (33 males and 25 females) and n=70 of whom were age- and IQ-matched typical controls (39 males and 31 females). ASC diagnosis (without any interaction with sex) strongly predicted androstenedione levels (p<0.01), and serum androstenedione levels were significantly elevated in the ASC group (Mann-Whitney W=2677, p=0.002), a result confirmed by permutation testing in females (permutation-corrected p=0.02). This result is discussed in terms of androstenedione being the immediate precursor of, and being converted into, testosterone, dihydrotestosterone, or estrogens in hormone-sensitive tissues and organs.
Publication
Journal: AIDS
January/12/2011
Abstract
OBJECTIVE
To assess predictors and reported treatment strategies of HIV-related fatigue in the combined antiretroviral (cART) era.
METHODS
Five databases were searched and reference lists of pertinent articles were checked. Studies published since 1996 on predictors or therapy of HIV-related fatigue measured by a validated instrument were selected.
RESULTS
A total of 42 studies met the inclusion criteria. The reported HIV-related fatigue prevalence in the selected studies varied from 33 to 88%. The strongest predictors for sociodemographic variables were unemployment and inadequate income. Concerning HIV-associated factors, the use of cART was the strongest predictor. Comorbidity and sleeping difficulties were important factors when assessing physiological influences. Laboratory parameters were not predictive of fatigue. The strongest and most uniform associations were observed between fatigue and psychological factors such as depression and anxiety. Reported therapeutic interventions for HIV-related fatigue include testosterone, psycho-stimulants (dextroamphetamine, methylphenidate hydrochloride, pemoline, modafinil), dehydroepiandrosterone, fluoxetine and cognitive behavioural or relaxation therapy.
CONCLUSIONS
HIV-related fatigue has a high prevalence and is strongly associated with psychological factors such as depression and anxiety. A validated instrument should be used to measure intensity and consequences of fatigue in HIV-infected individuals. In the case of fatigue, clinicians should not only search for physical mechanisms, but should question depression and anxiety in detail. There is a need for intervention studies comparing the effect of medication (antidepressants, anxiolytics) and behavioural interventions (cognitive-behavioural therapy, relaxation therapy, graded exercise therapy) to direct the best treatment strategy. Treatment of HIV-related fatigue is important in the care for HIV-infected patients and requires a multidisciplinary approach.
Publication
Journal: Journal of Neuroimmunology
August/7/2011
Abstract
We studied the features of parallel immunoneuroendocrine responses in patients with different degrees of chronic Chagas myocarditis (indeterminate, mild/moderate or severe). A systemic inflammatory scenario was evident in patients with severe myocarditis compared to healthy subjects. This was paralleled by a disrupted activation of the hypothalamus-pituitary-adrenal axis, characterized by decreased concentrations of dehydroepiandrosterone-sulfate (DHEA-s) and an unbalanced cortisol/DHEA-s ratio, reinforcing the view that severe Chagas disease is devoid of an adequate anti-inflammatory milieu, likely involved in pathology. Our study constitutes the first demonstration of neuroendocrine disturbances, in parallel to a systemic inflammatory profile, during progressive human Chagas disease.
Publication
Journal: Pharmacology Biochemistry and Behavior
December/19/2006
Abstract
Steroids from peripheral sources or synthesized in the brain, i.e. neurosteroids, exert rapid modulations of neurotransmitter responses through specific interactions with membrane receptors, mainly the gamma-aminobutyric acid type A (GABA(A)) receptor and N-methyl-d-aspartate (NMDA) type of glutamate receptor. Progesterone and 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone) act as inhibitory steroids while pregnenolone sulfate or dehydroepiandrosterone sulfate act as excitatory steroids. Some steroids also interact with an atypical protein, the sigma(1) (sigma(1)) receptor. This receptor has been cloned in several species and is centrally expressed in neurons and oligodendrocytes. Activation of the sigma(1) receptor modulates cellular Ca(2+) mobilization, particularly from endoplasmic reticulum pools, and contributes to the formation of lipid droplets, translocating towards the plasma membrane and contributing to the recomposition of lipid microdomains. The present review details the evidences showing that the sigma(1) receptor is a target for neurosteroids in physiological conditions. Analysis of the sigma(1) protein sequence confirmed homologies with the ERG2/emopamil binding protein family but also with the steroidogenic enzymes isopentenyl diphosphate isomerase and 17beta-estradiol dehydrogenase. Biochemical and physiological arguments for an interaction of neuro(active)steroids with the sigma(1) receptor are analyzed and the impact on physiopathological outcomes in neuroprotection is illustrated.
Publication
Journal: American Journal of Respiratory and Critical Care Medicine
May/9/2017
Abstract
Recent studies have focused on the role of female sex and estradiol (E2) in pulmonary arterial hypertension (PAH), but it is not known whether sex hormones are risk factors for PAH in men.
We performed a case-control study to determine whether hormone levels (E2, dehydroepiandrosterone-sulfate [DHEA-S], and testosterone) are associated with PAH in men.
Plasma sex hormone levels in men with idiopathic, heritable, or connective tissue disease-associated PAH were compared with those from age- and body mass index-matched men without clinical cardiovascular disease.
There were 23 cases with PAH (70% had idiopathic PAH, 65% were functional class III/IV) and 67 control subjects. Higher E2 and E2/testosterone levels were associated with the risk of PAH (odds ratio per 1 ln[E2:testosterone], 6.0; 95% confidence interval, 2.2-16.4; P = 0.001), whereas higher levels of DHEA-S were associated with a reduced risk (odds ratio per 1 ln[DHEA-S], 0.1; 95% confidence interval, 0.0-0.3; P = 0.001). E2 and DHEA-S levels were strong predictors of case status (C statistic for both, 0.82) but testosterone was not (C statistic, 0.53). Higher levels of E2 were associated with shorter 6-minute-walk distances (P = 0.03), whereas higher levels of DHEA-S were associated with lower right atrial pressure (P = 0.02) and pulmonary vascular resistance (P = 0.01) in men with PAH.
Higher levels of E2 and lower levels of DHEA-S were associated with PAH in men. Sex-based differences in sex hormone processing and signaling may contribute to unique phenotypes in pulmonary vascular disease.
Publication
Journal: Neurochemistry International
January/20/2003
Abstract
Nitric oxide (NO) has been implicated in the etiopathology of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), and inhibition of NO synthesis has been proposed to be a possible mechanism of action of drugs to treat MS. In the present study, we investigated the inhibitory effect on NO synthesis of various steroids, cytokines and drugs used or proposed for the treatment of MS. As a model system, we used primary rat microglial cells which produce NO synthase and subsequently release NO upon stimulation with lipopolysaccharide (LPS). Among the substances tested, the glucocorticoids prednisone, hydrocortisone, dexamethasone and progesterone as well as transforming growth factor-beta (TGF-beta) dose-dependently inhibited LPS-induced nitric oxide synthase (iNOS) and NO synthesis. In contrast, COP-1, the phosphodiesterase inhibitors rolipram and pentoxifylline, the cytokines interleukin-10 (IL-10) and interferon-beta (IFN-beta) as well as the steroids beta-estradiol, testosterone, and dehydroepiandrosterone (DHEA) showed no inhibitory effect. Cholesterol slightly, but not significantly, increased LPS-induced nitric oxide synthesis. We conclude from the present study that with respect to treatment of MS, inhibition of NO synthesis may be an important mechanism of action of glucocorticoids and transforming growth factor-beta, but not of other drugs used or proposed to treat MS.
Publication
Journal: Endocrinology
October/23/2006
Abstract
In the adult mammal the circadian system, which allows predictive adaptation to daily environmental changes, comprises peripheral oscillators in most tissues, commanded by the suprachiasmatic nucleus (SCN) of the hypothalamus. The external environment of the fetus is provided by its mother. In primates, maternal melatonin is a candidate to entrain fetal circadian rhythms, including the SCN rhythms of metabolic activity. We found in the 90% of gestation capuchin monkey fetus expression of the clock genes Bmal-1, Per-2, Cry-2, and Clock in the SCN, adrenal, pituitary, brown fat, and pineal. Bmal-1, Per-2, and the melatonin 1 receptor (MT1) showed a robust oscillatory expression in SCN and adrenal gland, whereas a circadian rhythm of dehydroepiandrosterone sulphate was found in plasma. Maternal melatonin suppression changed the expression of Bmal-1, Per-2, and MT1 in the fetal SCN. These effects were reversed by maternal melatonin replacement. In contrast, neither maternal melatonin suppression nor its replacement had effects on the expression of Per-2 and Bmal-1 or MT1 in the fetal adrenal gland or the circadian rhythm of fetal plasma dehydroepiandrosterone sulphate. Our data suggest that maternal melatonin is a Zeitgeber for the fetal SCN but probably not for the adrenal gland.
Publication
Journal: Human Reproduction Update
May/8/2013
Abstract
BACKGROUND
The aim of this meta-analysis was to evaluate the role of androgens or androgen-modulating agents on the probability of pregnancy achievement in poor responders undergoing IVF.
METHODS
Medline, EMBASE, CENTRAL, Scopus and Web of Science databases were searched for the identification of randomized controlled trials evaluating the administration of testosterone, dehydroepiandrosterone (DHEA), aromatase inhibitors, recombinant luteinizing hormone (rLH) and recombinant human chorionic gonadotrophin (rhCG) before or during ovarian stimulation of poor responders.
RESULTS
In two trials involving 163 patients, pretreatment with transdermal testosterone was associated with an increase in clinical pregnancy [risk difference (RD): +15%, 95% confidence interval (CI): +3 to +26%] and live birth rates (RD: +11%, 95% CI: +0.3 to +22%) in poor responders undergoing ovarian stimulation for IVF. No significant differences in clinical pregnancy and live birth rates were observed between patients who received DHEA and those who did not. Similarly, (i) the use of aromatase inhibitors, (ii) addition of rLH and (iii) addition of rhCG in poor responders stimulated with rFSH for IVF were not associated with increased clinical pregnancy rates. In the only eligible study that provided data, live birth rate was increased in patients who received rLH when compared with those who did not (RD: +19%, 95% CI:+1 to +36%).
CONCLUSIONS
Based on the limited available evidence, transdermal testosterone pretreatment seems to increase clinical pregnancy and live birth rates in poor responders undergoing ovarian stimulation for IVF. There is insufficient data to support a beneficial role of rLH, hCG, DHEA or letrozole administration in the probability of pregnancy in poor responders undergoing ovarian stimulation for IVF.
Publication
Journal: Journal of Extracellular Vesicles
November/13/2018
Abstract
Urine contains extracellular vesicles (EVs) that concentrate molecules and protect them from degradation. Thus, isolation and characterisation of urinary EVs could increase the efficiency of biomarker discovery. We have previously identified proteins and RNAs with differential abundance in urinary EVs from prostate cancer (PCa) patients compared to benign prostate hyperplasia (BPH). Here, we focused on the analysis of the metabolites contained in urinary EVs collected from patients with PCa and BPH. Targeted metabolomics analysis of EVs was performed by ultra-high-performance liquid chromatography-mass spectrometry. The correlation between metabolites and clinical parameters was studied, and metabolites with differential abundance in PCa urinary EVs were detected and mapped into cellular pathways. We detected 248 metabolites belonging to different chemical families including amino acids and various lipid species. Among these metabolites, 76 exhibited significant differential abundance between PCa and BPH. Interestingly, urine EVs recapitulated many of the metabolic alterations reported in PCa, including phosphathidylcholines, acyl carnitines, citrate and kynurenine. Importantly, we found elevated levels of the steroid hormone, 3beta-hydroxyandros-5-en-17-one-3-sulphate (dehydroepiandrosterone sulphate) in PCa urinary EVs, in line with the potential elevation of androgen synthesis in this type of cancer. This work supports urinary EVs as a non-invasive source to infer metabolic changes in PCa.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
June/30/2003
Abstract
Progesterone (P) is a potent antagonist of the human mineralocorticoid receptor (MR) in vitro. We have previously demonstrated effective downstream metabolism of P in the kidney. This mechanism potentially protects the MR from P action. Here, we have investigated the expression and functional activity of steroidogenic enzymes in human kidney. RT-PCR analysis demonstrated the expression of 5 alpha-reductase type 1, 5 beta-reductase, aldo-keto-reductase (AKR) 1C1, AKR1C2, AKR1C3, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) type 2, and 17 alpha-hydroxylase/17,20-lyase (P450c17). The presence of 3 beta-HSD type 2 and P450c17 indicated that conversion of pregnenolone to dehydroepiandrosterone (DHEA) and to androstenedione may take place effectively in kidney. To investigate this further, we incubated kidney subcellular fractions with radiolabeled pregnenolone. This resulted in efficient formation of DHEA from pregnenolone, indicating both 17 alpha-hydroxylase and 17,20-lyase activities exerted by P450c17. Radiolabeled DHEA was converted via androstenedione, androstenediol, and testosterone, indicating both 3 beta-HSD type 2 activity and 17 beta-HSD activity. In addition, the conversion of testosterone to 5 alpha-dihydrotestosterone was detectable, indicating 5 alpha-reductase activity. In conclusion, we verified the expression and functional activity of several enzymes involved in downstream metabolism of P and androgen synthesis in human kidney. These findings may be critical to the understanding of water balance during the menstrual cycle and pregnancy and of sex differences in hypertension.
Publication
Journal: Metabolism: Clinical and Experimental
May/22/1995
Abstract
It has been reported that a high proportion of abdominal fat is associated with increased plasma androgen concentrations in women. Although less evidence is available, abdominal obesity appears to be associated with low plasma testosterone (T) levels in men. We have therefore examined in 80 men (aged 36.3 +/- 3.2 years, mean +/- SD) the correlations between body fatness, adipose tissue (AT) distribution measured by computed tomography (CT), and circulating levels of the following steroids measured by radioimmunoassay after extraction from serum and chromatography: dehydroepiandrosterone (DHEA), androstenedione (delta 4-DIONE), androst-5-ene-3 beta,17 beta-diol (delta 5-DIOL), T, estrone, and estradiol. Sex hormone-binding globulin (SHBG) levels were also determined. T, adrenal C19 steroids, and SHBG levels were negatively correlated with total body fatness indices and abdominal fat deposition measured by CT (-.23 < or = -.55, .0001 < or = P < or = .05), whereas estrone showed positive correlations with these body fatness and AT distribution indices. Covariance analysis showed that after control for the concentration of the adrenal steroid precursor delta 5-DIOL, there was no residual association between T levels and adiposity variables. Furthermore, multivariate analyses showed that steroid and SHBG levels could explain from 20% (visceral AT area measured by CT) to 40% and 42% (body mass index [BMI], waist circumference, and waist to hip ratio [WHR]) of the variation in adiposity variables (.0001 < or = P < or = .05), with delta 5-DIOL being the best single correlate of body fatness and abdominal fat deposition in men.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication
Journal: Fertility and Sterility
March/20/2006
Abstract
OBJECTIVE
To determine whether eucaloric diets either enriched with monounsaturated fatty acids (MUFA; 17% energy) or low in carbohydrates (Low CHO; 43% energy) would increase insulin sensitivity (Si) and decrease circulating insulin concentrations, relative to a standard diet (STD; 56% CHO, 31% fat, 16% protein), among women with polycystic ovary syndrome (PCOS).
METHODS
Crossover.
METHODS
Academic research environment.
METHODS
Healthy women with PCOS not on hormonal or insulin-sensitizing therapy.
METHODS
Subjects consumed three, 16-day, eucaloric diets, each separated by a 3-week washout period. A frequently sampled, intravenous, glucose tolerance test was administered at baseline and following each diet.
METHODS
Fasting glucose, insulin, the acute insulin response to glucose (AIRg), Si, sex hormone-binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEAS), total testosterone (T), free T, A4, total cholesterol, high-density lipoprotein cholesterol (HDL-C), tryglycerides (TG), and free fatty acids (FFA).
RESULTS
Fasting insulin was lower following the Low CHO diet relative to the STD diet; AIRg was lower following the Low CHO diet relative to the MUFA diet. Fasting glucose, Si, and the circulating concentrations of reproductive hormones were not significantly affected by the intervention.
CONCLUSIONS
A moderate reduction in dietary carbohydrate reduced the fasting and postchallenge insulin concentrations among women with PCOS, which, over time, may improve reproductive/endocrine outcomes.
Publication
Journal: NeuroImmunoModulation
February/25/2009
Abstract
This paper reviews recent work suggesting that human immunosenescence may be closely related to both chronic stress and stress hormones. The age-related immunological changes are also similarly found during chronic stress or glucocorticoid exposure. These data further suggest that endogenous glucocorticoids could be associated with immunosenescence. When compared with young subjects, healthy elders are emotionally distressed in parallel to increased cortisol/dehydroepiandrosterone ratio. Furthermore, chronically stressed elderly subjects may be particularly at risk of stress-related pathology because of further alterations in glucocorticoid-immune signaling. Age-related increase in cortisol/dehydroepiandrosterone ratio could be understood as a major determinant of immunological changes observed during aging. Strictly healthy elders are somewhat protected from chronic stress exposure and show normal cortisol levels and increased T cell function. This information adds a new key dimension to the biology of aging and stress.
Publication
Journal: Molecular and Cellular Endocrinology
March/4/2004
Abstract
Androgens and estrogens are made from dehydroepiandrosterone (DHEA), which is made from cholesterol via four steps. First, cholesterol enters the mitochondria with the assistance of the steroidogenic acute regulatory protein (StAR). Mutations in the StAR gene cause congenital lipoid adrenal hyperplasia. Second, within the mitochondria, cholesterol is converted to pregnenolone by the cholesterol side chain cleavage enzyme, P450scc. Third, pregnenolone undergoes 17alpha-hydroxylation by microsomal P450c17. Finally, 17-OH pregnenolone is converted to DHEA by the 17,20 lyase activity of P450c17. The ratio of the 17,20 lyase to 17alpha-hydroxylase activity of P450c17 determines the ratio of C21 to C19 steroids produced. This ratio is regulated post-translationally by at least three factors: the abundance of the electron-donating protein P450 oxidoreductase, the presence of cytochrome b(5), and the serine phosphorylation of P450c17. Study of these and related factors may yield important information about the pathophysiology of adrenarche and the polycystic ovary syndrome (PCOS).
Publication
Journal: Annals of Internal Medicine
August/27/1980
Abstract
Low doses of mitotane were given orally to 36 patients with Cushing's disease, concurrently with or after pituitary cobalt irradiation. Clinical and biochemical remission occurred in 29. The response to treatment occurred early in 17 patients and late in 12. The different pattern of response to mitotane was not related to the dose given or to its serum level. Early biochemical indicators of adrenal suppression with mitotane were a sharp decrease in adrenal response to the infusion of ACTH and in plasma levels of dehydroepiandrosterone sulfate. Although mitotane was given together with pituitary irradiation, initial remission was due mainly to the adrenal effect of mitotane. Plasma ACTH levels were still elevated when cortisol had returned to normal. In seventeen of the 29 patients who responded to treatment drug therapy has been discontinued, and they remain in remission of Cushing's syndrome. Side-effects have been dose dependent, with anorexia, nausea, decreased memory, and gynecomastia in men being the commonest.
Publication
Journal: Stress
September/21/2005
Abstract
We use a population-based representative sample of older Taiwanese to investigate links between respondents' perceived levels of stress and a broad set of biological measures. These biomarkers were collected at a single time (2000) and reflect sympathetic nervous system (SNS)-activity, hypothalamo-pituitary-adrenal (HPA)-activity, immune function, cardiovascular function, and metabolic pathways. We model the relationship between perceived stress and (1) extreme values for each of 16 individual biological indicators; and (2) a measure of cumulative physiological dysregulation based on the full set of biomarkers. We consider two measures of perceived stress, one derived from the 2000 interview and the second based on data from three interviews (1996-2000). Age and sex-adjusted models reveal significant associations between measures of perceived stress and extreme values of cortisol, triglycerides, interleukin-6 (IL-6), dehydroepiandrosterone sulphate (DHEAS) and fasting glucose. Examined individually, numerous biomarkers, including those pertaining to blood pressure and obesity, are not significantly related to perceived stress. Jointly, however, the measure of cumulative physiological dysregulation is associated with both the level of perceived stress at a given time and to a longitudinal measure of perceived stress. Some results suggest that the relationship between level of perceived stress and physiological response is stronger for women than men.
Publication
Journal: Osteoporosis International
August/12/2013
Abstract
There is a need to understand the role of nutrition, beyond calcium and vitamin D, in the treatment and prevention of osteoporosis in adults. Results regarding soy compounds on bone density and bone turnover are inconclusive perhaps due to differences in dose and composition or in study population characteristics. The skeletal benefit of black cohosh and red clover are unknown. Dehydroepiandrosterone (DHEA) use may benefit elderly individuals with low serum dehydroepiandrosterone-sulfate levels, but even in this group, there are inconsistent benefits to bone density (BMD). Higher fruit and vegetable intakes may relate to higher BMD. The skeletal benefit of flavonoids, carotenoids, omega-3-fatty acids, and vitamins A, C, E and K are limited to observational data or a few clinical trials, in some cases investigating pharmacologic doses. Given limited data, it would be better to get these nutrients from fruits and vegetables. Potassium bicarbonate may improve calcium homeostasis but with little impact on bone loss. High homocysteine may relate to fracture risk, but the skeletal benefit of each B vitamin is unclear. Magnesium supplementation is likely only required in persons with low magnesium levels. Data are very limited for the role of nutritional levels of boron, strontium, silicon and phosphorus in bone health. A nutrient rich diet with adequate fruits and vegetables will generally meet skeletal needs in healthy individuals. For most healthy adults, supplementation with nutrients other than calcium and vitamin D may not be required, except in those with chronic disease and the frail elderly.
Authors
Publication
Journal: Human Molecular Genetics
June/30/2013
Abstract
Human CYP3A is the most abundant P450 isozyme present in the human liver and small intestine, and metabolizes around 50% of medical drugs on the market. The human CYP3A subfamily comprises four members (CYP3A4, CYP3A5, CYP3A7, CYP3A43) encoded on human chromosome 7. However, transgenic mouse lines carrying the entire human CYP3A cluster have not been constructed because of limitations in conventional cloning techniques. Here, we show that the introduction of a human artificial chromosome (HAC) containing the entire genomic human CYP3A locus recapitulates tissue- and stage-specific expression of human CYP3A genes and xenobiotic metabolism in mice. About 700 kb of the entire CYP3A genomic segment was cloned into a HAC (CYP3A-HAC), and trans-chromosomic (Tc) mice carrying a single copy of germline-transmittable CYP3A-HAC were generated via a chromosome-engineering technique. The tissue- and stage-specific expression profiles of CYP3A genes were consistent with those seen in humans. We further generated mice carrying the CYP3A-HAC in the background homozygous for targeted deletion of most endogenous Cyp3a genes. In this mouse strain with 'fully humanized' CYP3A genes, the kinetics of triazolam metabolism, CYP3A-mediated mechanism-based inactivation effects and formation of fetal-specific metabolites of dehydroepiandrosterone observed in humans were well reproduced. Thus, these mice are likely to be valuable in evaluating novel drugs metabolized by CYP3A enzymes and in studying the regulation of human CYP3A gene expression. Furthermore, this system can also be used for generating Tc mice carrying other human metabolic genes.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
June/30/2000
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
July/1/1999
Abstract
Recent reports indicate that girls with premature adrenarche are at risk of developing functional ovarian hyperandrogenism and polycystic ovarian syndrome (PCOS). As insulin and insulin-like growth factors (IGFs) have been implicated in the pathogenesis of PCOS, we hypothesize that they may also have a role in the hyperandrogenism of premature adrenarche. Thirty-five prepubertal girls (23 Caribbean Hispanics and 12 Black African-Americans) underwent a 60-min ACTH and LH-releasing hormone test. Insulin sensitivity (S(I)) was assessed using the frequently sampled i.v. glucose tolerance test with tolbutamide. Fasting levels of IGF-I, IGF-binding protein-1 (IGFBP-1), IGFBP-3, sex hormone-binding globulin, and free testosterone (T) were also obtained. The mean age of the patients was 6.8 yr, and bone age was 8.0 yr. Twenty-five patients had a family history of noninsulin-dependent diabetes mellitus and 19 patients had acanthosis nigricans. The mean S(I) for the entire group was 6.78 +/- 5.21 x 10(-4) min/microU x mL (normal prepubertal S(I), 6.5 +/- 0.54 x 10(-4) min(-1) x microU(-1) x mL(-1)). However, 15 of the 35 girls had an S(I) that was more than 2 SD below the mean reported for normal prepubertal children. Of these 15 patients, 13 were obese, and 14 had acanthosis nigricans. For the entire group of girls, the mean ACTH-stimulated levels of 17-hydroxypregnenolone (17OHPreg), dehydroepiandrosterone (DHEA), androstenedione (AS), 17-hydroxyprogesterone (17OHP), and T and the ACTH-stimulated ratios of 17OHPreg/17OHP, 17OHPreg/DHEA, 17OHP/AS, and DHEA/AS did not differ from the levels reported for Tanner stage II-III pubertal girls. The girls were divided into two groups based on their S(I) (group I, S(I) >2 SD below the mean for age; group II, normal S(I)). The group I girls with a reduced S(I) had significantly higher ACTH-stimulated levels of 17OHPreg (group I, 760 +/- 87.84 ng/dL; group II, 428.9 +/- 46.28 ng/dL; P = 0.002), 17OHPreg/17OHP ratio (group I, 3.95 +/- 0.36; group II, 2.96 +/- 0.35; P = 0.05), 17OHPreg/DHEA (group I, 2.06 +/- 0.21; group II, 1.4 +/- 0.13; P = 0.01), and free T (group I, 1 +/- 0.23 ng/dL; group II, 0.49 +/- 0.19 ng/dL; P = 0.014). Levels of sex hormone-binding globulin were lower in the group I girls. Furthermore, for the entire group of girls, the S(I) correlated inversely with ACTH-stimulated levels of 17OHPreg, DHEA, and AS and the ACTH-stimulated ratio of 17OHPreg/17OHP. IGF-I correlated inversely with S(I) (r = -0.94; P < 0.001) and correlated directly with the ACTH-stimulated levels of 17OHPreg (r = 0.8; P < 0.001) and AS (r = 0.63; P < 0.05). IGF-I also correlated with the ACTH-stimulated ratios of 17OHPreg/17OHP (r = 0.61; P < 0.05), 17OHPreg/DHEA (r = 0.9; P < 0.001), 17OHP/AS (r = 0.79; P < 0.001), and DHEA/AS (r = 0.96; P < 0.001). IGFBP-1 correlated inversely with the ACTH-stimulated levels of 17OHPreg (r = -0.38; P < 0.05) and DHEA (r = -0.36; P < 0.05). To summarize, the ACTH-stimulated delta5-steroid levels were higher in prepubertal girls with premature adrenarche and reduced S(I). There was a significant inverse correlation among ACTH-stimulated hormone levels, S(I), and IGFBP-1, whereas IGF-I correlated directly with ACTH-stimulated androgens. These findings support the hypothesis that insulin and IGFs may have a role in the hyperandrogenism of premature adrenarche just as they do in PCOS. Hence, in certain girls with premature adrenarche, hyperandrogenism may be the first presentation of PCOS and/or insulin resistance.
Publication
Journal: Atherosclerosis
January/15/2013
Abstract
OBJECTIVE
Sex steroid hormones have been postulated to involve in blood pressure (BP) regulation. We examine the association of endogenous sex hormone levels with longitudinal change of BP and risk of developing hypertension in initially normotensive postmenopausal women.
METHODS
We conducted prospective analysis among 619 postmenopausal women free of hypertension at baseline in the Multi-Ethnic Study of Atherosclerosis (MESA). Change of BP and development of incident hypertension were assessed during a mean of 4.8 years follow-up.
RESULTS
After adjusting for age, race/ethnicity, and lifestyle factors, baseline serum estradiol (E(2)), total and bioavailable testosterone (T), dehydroepiandrosterone (DHEA) were each positively associated and sex-hormone binding globulin (SHBG) was inversely associated with risk of hypertension. Additional adjustment for body mass index eliminated the associations for E(2) and T but only attenuated the associations for DHEA and SHBG. The corresponding multivariable hazard ratios (95% CIs) in the highest quartile were 1.28 (0.83-1.97) for E(2), 1.38 (0.89-2.14) for total T, 1.42 (0.90-2.23) for bioavailable T, 1.54 (1.02-2.31) for DHEA, and 0.48 (0.30-0.76) for SHBG. Adjustment for fasting glucose, insulin, and C-reactive protein further attenuated the association for DHEA but not for SHBG. Associations of sex hormones with longitudinal BP change were similar.
CONCLUSIONS
In postmenopausal women, higher endogenous E(2), T, and DHEA and lower SHBG were associated with higher incidence of hypertension and greater longitudinal rise in BP. The associations for E(2), T, and DHEA were mostly explained by adiposity, while the association for SHBG was independent of measures of adiposity, insulin resistance, and systemic inflammation.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
August/6/1997
Abstract
The adrenal steroids, dehydroepiandrosterone (DHEA) and its sulfate (DHEAS), have attracted attention for their possible antiaging effects. DHEAS levels in humans decline markedly with age, suggesting the potential importance of this parameter as a biomarker of aging. Here we report that, as seen in humans, male and female rhesus monkeys exhibit a steady, age-related decline in serum DHEAS. This decline meets several criteria for a biomarker of aging, including cross-sectional and longitudinal linear decreases with age and significant stability of individual differences over time. In addition, the proportional age-related loss of DHEAS in rhesus monkeys is over twice the rate of decline observed in humans. Most important is the finding that, in rhesus monkeys, calorie restriction, which extends life span and retards aging in laboratory rodents, slows the postmaturational decline in serum DHEAS levels. This represents the first evidence that this nutritional intervention has the potential to alter aspects of postmaturational aging in a long-lived species.
Publication
Journal: Journal of Pharmacology and Experimental Therapeutics
January/11/2006
Abstract
A novel member of the organic anion transporter (OAT) family, Oat5 (Slc22a19), has been reported to transport a naturally occurring mycotoxin, ochratoxin A (OTA). However, neither its endogenous substrate and driving force nor physiological functions have been determined. Herein, we report the functional characterization of rat Oat5 (rOat5), as well as its intrarenal distribution and membrane localization. When expressed in Xenopus laevis oocytes, rOat5 mediated the transport of sulfate conjugates of steroids such as estrone-3-sulfate (E(1)S; K(m) = 18.9 +/- 3.9 microM) and dehydroepiandrosterone sulfate (K(m) = 2.3 +/- 0.2 microM) in a sodium-independent manner, in addition to OTA. The rOat5-mediated E(1)S transport was strongly inhibited by four-carbon (C4) dicarboxylate succinate and longer dicarboxylates (C7-C9). The uptake of [(3)H]E(1)S via rOat5 was significantly trans-stimulated by succinate, and the efflux of [(14)C]succinate was significantly trans-stimulated by E(1)S. A similar trans-stimulatory effect of preloaded succinate on E(1)S uptake was also detected in cells stably expressing rOat5 (S(2) rOat5). rOat5 interacted with chemically heterogenous anionic compounds. The rOat5-mediated E(1)S transport was inhibited by several sulfate conjugates, such as 4-methylumbelliferyl sulfate and beta-estradiol sulfate, but not by glucuronide conjugates. An immunohistochemical study showed that rOat5 was localized at the apical membrane of renal proximal tubules in the corticomedullary region. rOat5 mRNA was expressed in the late segments (S(2) and S(3)) of proximal tubules. These results indicate that rOat5 is renal organic anion/dicarboxylates exchanger and, under physiological conditions, may function as an apical reabsorptive pathway for organic anions in proximal tubules driven by an outward gradient of dicarboxylates.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
February/7/1993
Abstract
Five steroids--3 beta-hydroxypregn-5-en-20-one (pregnenolone; P), 3 beta-hydroxy-5 alpha-pregnan-20-one (3 beta-AP), 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-AP), 3 beta-hydroxyandrost-5-en-17-one (dehydroepiandrosterone; D), and 3 beta-hydroxy-5 alpha-androstan-17-one (EpiA)--were extracted from the brains of adult male rats, rabbits, and dogs. The steroids exist in this organ as unconjugated compounds and as sulfates, lipoidal esters, and sulfolipids. The techniques for separating these four classes of steroids from each other and for separating the five steroids from each other are described. In all cases, the steroids were identified by their retention time (Rt) on HPLC, their Rt by gas chromatography, and by selected ion monitoring of their mass spectra. The latter were also used for quantification. In their reaction toward organic bases, the sulfolipid conjugates resemble previously described sulfolipids of cholesterol and sitosterol. These conjugates are relatively abundant in brain, particularly those of P and D, and this suggests that, in the search for the physiological significance of these brain constituents, these conjugates warrant attention.
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