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Publication
Journal: Neuroscience
May/17/2006
Abstract
Hippocampal pyramidal neurons and granule neurons of adult male rats are equipped with a complete machinery for the synthesis of pregnenolone, dehydroepiandrosterone, testosterone, dihydrotestosterone and 17beta-estradiol. Both estrogens and androgens are synthesized in male hippocampus. These brain steroids are synthesized by cytochrome P450s (P450scc, P45017alpha and P450arom), hydroxysteroid dehydrogenases and reductases from endogenous cholesterol. The expression levels of enzymes are as low as 1/300-1/1000 of those in endocrine organs. Synthesis is dependent on the acute Ca(2+) influx upon neuron-neuron communication via NMDA receptors. Estradiol is particularly important because estradiol rapidly modulates neuronal synaptic transmission such as long-term potentiation via synaptic estrogen receptors. Xenoestrogens may also act via estrogen-driven signaling pathways.
Publication
Journal: Biology of Reproduction
August/7/2003
Abstract
The Nonhuman Primate Models of Menopause Workshop was held on the National Institutes of Health campus in January 2001. The purpose of this workshop, sponsored by the National Institute on Aging, was to review what is known about the female reproductive aging process in various species of monkeys (particularly rhesus, baboons, cynomolgus, and chimpanzees), including hormone profiles during the menopausal transition, occurrence of hot flashes, extent of age-related and menopause-associated changes in hormone levels on metabolism, bone loss, and impaired cardiovascular and cognitive function. Many aspects of the female reproductive aging process appear to be concordant between humans and these monkey species, but several important features may be species-specific. Those features that appear to parallel human menopause and aging include general similarity of hormone profiles across the menopausal transition, progression to cycle termination through irregular cycles, declining fertility with age, age-related gains in weight and percentage body fat content (with tendencies toward insulin resistance and glucose intolerance), increased low-density lipoprotein cholesterol and decreased high-density lipoprotein cholesterol, declines in serum dehydroepiandrosterone, similarities in temperature-regulation systems, protective responses to estrogen replacement following ovariectomy in terms of bone metabolism, lipid profiles, and cognitive changes. Important differences include relatively short postmenopausal life span, timing in menopause-related changes in hormone secretion, and seasonal menstrual cycles. In addition, the question of whether ovariectomy in young adults is an appropriate model for the consequences of natural or surgical menopause in middle-aged and older adults is unresolved, and the numbers of older female animals available for research on menopause are very limited. The use of animal models is seen by workshop participants to be crucial for a mechanistic understanding of the human menopausal process and its connections to postmenopausal health problems; however, extensive in-depth and broad-based research is required to determine if nonhuman primates are appropriate models of human menopause.
Publication
Journal: Journal of Neuroscience
June/18/2003
Abstract
The sigma1 receptor is critically involved in the rewarding effect of cocaine, as measured using the conditioned place preference (CPP) procedure in mice. Neuroactive steroids exert rapid neuromodulatory effects in the brain by interacting with GABA(A), NMDA, and sigma1 receptors. At the sigma1 receptor level, 3beta-hydroxy-5-androsten-17-one [dehydroepiandrosterone (DHEA)] and 3beta-hydroxy-5-pregnen-20-one (pregnenolone) act as agonists, whereas 4-pregnene-3,20-dione (progesterone) is an efficient antagonist. The present study sought to investigate the action of neuroactive steroids in acquisition of cocaine-induced CPP in C57BL/6 mice. None of these steroids induced CPP alone. However, pretreatment with DHEA or pregnenolone (5-20 mg/kg, s.c.) during conditioning with cocaine (10 mg/kg, i.p.) increased the conditioned score. On the contrary, pretreatment with either progesterone (10 or 20 mg/kg, s.c.) or finasteride (25 mg/kg, twice a day), a 5alpha-reductase inhibitor, blocked acquisition of cocaine (20 mg/kg)-induced CPP. A crossed pharmacology was observed between steroids and sigma1 ligands. The sigma1 antagonist N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino)ethylamine blocked cocaine-induced CPP and its potentiation by DHEA or pregnenolone. Progesterone blocked cocaine-induced CPP and its potentiation by the sigma1 agonist igmesine. These results showed that neuroactive steroids play a role in cocaine-induced appetence, through their interaction with the sigma1 receptor. Therefore, neuroendocrine control of cocaine addiction may not involve solely glucocorticoids. The importance of neuroactive steroids as factors of individual vulnerability to drug addiction should, thus, be considered.
Publication
Journal: The journals of gerontology. Series A, Biological sciences and medical sciences
April/23/2015
Abstract
BACKGROUND
Multimorbidity increases with aging, but risk factors beyond age are unknown.
OBJECTIVE
To investigate the association of inflammatory and anabolic hormonal biomarkers with presence and prospective development of multimorbidity.
METHODS
Nine-year longitudinal study of 1018 participants aged 60 years or older (InCHIANTI Study). Multimorbidity was evaluated at baseline and follow-up visits as number of diagnosed diseases from a predefined list of 15 candidate chronic conditions, defined according to standard clinical criteria. Linear mixed models were used to test cross-sectional and longitudinal associations between candidate biomarkers and multimorbidity.
RESULTS
At baseline, multimorbidity was significantly higher in older participants (p < .001) and higher IL-6, IL-1ra, TNF-α receptor II (TNFAR2), and lower dehydroepiandrosterone sulfate were associated with higher number of diseases, independent of age, sex, body mass index, and education. The rate of longitudinal increase in number of chronic diseases was significantly steeper in participants who were older at baseline (p < .001). In addition, higher baseline IL-6 and steeper increase of IL-6 levels were significantly and independently associated with a steeper increase in multimorbidity over time (p < .001 and p = .003, respectively). Sensitivity analyses, performed using 15 different models obtained by removing each of 15 conditions included in the original list of candidate diseases, confirmed that results were not driven by any specific condition.
CONCLUSIONS
Accumulation of chronic diseases accelerates at older ages and in persons with higher baseline levels and steeper increase over time of IL-6. High IL-6 and increase in IL-6 may serve as early warning sign to better target interventions aimed at reducing the burden of multimorbidity.
Publication
Journal: American Journal of Physiology - Endocrinology and Metabolism
November/20/2006
Abstract
The plasma levels of dehydroepiandrosterone (DHEA) and its sulfated form (DHEAS) decline approximately 80% between the ages of 25 and 75 yr. Muscle mass and strength also decrease with aging. Published data on the effects of DHEA replacement on muscle mass and strength are conflicting. The goals of this study were to determine whether DHEA replacement increases muscle mass and strength and/or enhances the effects of heavy resistance exercise in elderly women and men. We conducted a randomized, double-blind, placebo-controlled study of the effects of 10 mo of DHEA replacement therapy with the addition of weightlifting exercise training during the last 4 mo of the study (DHEA + exercise group, n = 29; placebo + exercise group, n = 27). DHEA alone for 6 mo did not significantly increase strength or thigh muscle volume. However, DHEA therapy potentiated the effect of 4 mo of weightlifting training on muscle strength, evaluated by means of one-repetition maximum measurement and Cybex dynamometry, and on thigh muscle volume, measured by magnetic resonance imaging. Serum insulin-like growth factor concentration increased in response to DHEA replacement. This study provides evidence that DHEA replacement has the beneficial effect of enhancing the increases in muscle mass and strength induced by heavy resistance exercise in elderly individuals.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
July/1/1998
Abstract
Women with adrenal insufficiency suffer from chronic dehydroepiandrosterone (sulfate) [DHEA(S)] deficiency. To define a suitable dose for DHEA replacement, we studied the pharmacokinetics and biotransformation of orally administered DHEA in nine healthy female volunteers (mean age 23.3 +/- 4.1 yr, mean body mass index 22.5 +/- 1.8 kg/m2) with transient suppression of adrenal androgen secretion because of dexamethasone (dex) administration (4 x 0.5 mg/day for 4 days). Diurnal blood sampling was performed during the early follicular phase of four subsequent menstrual cycles (study period 1: baseline; study periods 2-4: dex + placebo, dex + 50 mg DHEA or dex + 100 mg DHEA in a randomized cross-over design). Dex induced not only a significant suppression of serum cortisol (to 8% of baseline) but also of DHEA (18%), DHEA(S) (16%), and androstenedione (26%), as well as of testosterone (28%), dihydrotestosterone (43%), and estrone (54%). Oral administration of 50 mg DHEA led to restoration of DHEA(S) baseline levels, whereas 100 mg induced supraphysiological concentrations [baseline vs. 50 mg DHEA vs. 100 mg DHEA: area under the concentration-time curve (AUC) 0-12 h DHEA: 280 +/- 85 vs. 241 +/- 73 vs. 383 +/- 106 nmol/L x h; AUC 0-12 h DHEA(S): 89.1 +/- 48.4 vs. 139.6 +/- 43.5 vs. 213.3 +/- 21.6 mumol/L x h). Serum concentrations of dihydrotestosterone and estrone were restored to baseline after 50 mg DHEA, whereas baseline testosterone and androstenedione levels were only achieved by administration of 100 mg DHEA. In conclusion, 50 mg DHEA seems to be a suitable replacement dose in females with adrenal insufficiency. Furthermore, the rapid and lasting conversion to potent androgens demonstrates a potential role of DHEA for androgen replacement in females in general.
Publication
Journal: Steroids
September/8/2011
Abstract
BACKGROUND
Cigarette tobacco smoke is a potent environmental contaminant known to adversely affect health including fertility and pregnancy.
OBJECTIVE
To examine the associations between second-hand cigarette tobacco-smoke exposure, or active smoking and serum concentrations of steroid hormones using tandem mass spectrometry.
METHODS
Healthy women (18-45 y) from the general community in the Metropolitan Washington, DC were recruited at the follicular stage of their menstrual cycle. Participants were assigned to one of three study groups: active smokers (N=107), passive smokers (N=86), or non-smokers (N=100). Classifications were based on a combination of self-reporting and serum cotinine concentrations.
METHODS
Serum androgens, estrogens, progestins, androstenedione, aldosterone, cortisol, corticosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), 11-deoxycortisol and 25-hydroxy-vitamin D3 (25-OHVitD3) and cotinine were measured by isotope dilution tandem mass spectrometry (LC/MS/MS) (API-5000). Kruskal-Wallis tests were used to assess median differences among the three groups, with Dunn's multiple comparison test for post hoc analysis.
RESULTS
Serum estrone, estradiol, and estriol concentrations were lower in active and passive smokers than in non-smokers. The three study groups differed significantly in serum concentrations of 16-OHE1, aldosterone and 25-OHVitD3, as well as in the ratios of many of the steroids. Pair-wise comparison of the groups demonstrated significant differences in hormone concentrations between (i) smokers and non-smokers for aldosterone: (ii) passive smokers and non-smokers for aldosterone, progesterone and estriol. Moreover, for smokers and passive smokers, there were no significant differences in these hormone concentrations.
CONCLUSIONS
Smoke exposure was associated with lower than normal median steroid hormone concentrations. These processes may be instrumental in explaining some adverse effects of tobacco smoke on female health and fertility.
Publication
Journal: Current Drug Metabolism
April/21/2008
Abstract
The sulfotransferase (SULTs) catalyzes the sulfonation of a multitude of xenobiotics, hormones and neurotransmitters. This review has summarised the SULT family in detail, the structure of the twelve known enzymes, in their four known groups (SULT1, SULT2, SULT4, and SULT6) and the substrates for each respective SULT. Hepatic sulfonation is a common phase II metabolic mechanism for increasing molecular hydrophilicity in preparation for biliary excretion or efflux across the hepatic basolateral membrane for subsequent renal clearance. To date, a total of 13 human cytosolic SULT genes have been identified which spread across four families; SULT1, SULT2, SULT4, and SULT6. The established structures of SULTs provide evidence for both enzyme/substrate and enzyme/cofactor binary complexes, consistent with a random bi-bi mechanism and ruling out an ordered mechanism in which binding of substrate requires binding of cofactor (or vice versa). Members of the SULT1 family have demonstrated the ability to sulfonate simple (small planar) phenols including estradiol, thyroid hormones, environmental xenobiotics and drugs. The SULT2 family members catalyze sulfonation of hydroxyl groups of steroids, such as androsterone, allopregnanolone, and dehydroepiandrosterone. As yet, no known substrate or function has been identified for the SULT4 family, and the SULT6B1 gene, expressed in the testis of primates, has neither the protein nor its enzymatic activity characterized. The extent of nucleotide variation found in members of the SULT gene family is similar to that observed for other groups of human genes. Substrate inhibition was observed for most substrates with a trend in maximum velocity (V(max)) of *1>*3>*2. There does appear to be an inter-ethnic/inter-racial difference in the incidence of the various SULT1A1 alleles also. There is mounting evidence to suggest that further research and understanding in the area of phase II metabolism and the SULT enzyme will have a great benefit in a clinical setting. Already research in the field is finding links with cancer and sulfonation-related disease, promising to deliver great advances in clinical practice in the future.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
April/15/1985
Abstract
Vertebral mineral density, measured by computerized axial tomography, radiocalcium absorption, serum dehydroepiandrosterone (DHA), and serum cortisol (C) were measured in 98 postmenopausal women aged 56-70 yr. On the basis of spine radiographs and fracture history, the women were classified into 49 normal subjects (mean age, 60.5 yr) and 49 with osteoporosis (mean age, 63.1 yr). Vertebral mineral density (VMD), radiocalcium absorption (alpha), serum DHA, and the ratio of DHA to cortisol (DHA/C) were all significantly lower in the osteoporotic than in the normal subjects. DHA was significantly related to C in both groups but the regression was significantly flatter in the osteoporotic than in the normal subjects. Calcium absorption did not fall significantly with age in either group. In the normal group VMD, DHA, and DHA/C fell with age but VMD was not related to alpha, DHA, or DHA/C. In the osteoporotic group, VMD did not fall significantly with age but was significantly related to alpha and DHA/C. Stepwise regression analysis showed that in the normal subjects, age was the only variable significantly related to VMD (P less than 0.05). In the osteoporotic group, calcium absorption was the main determinant of VMD, with age and DHA/C contributing much less to the variance. Discriminant function analysis showed a theoretical misclassification of 45% of cases using DHA, 39% using DHA/C, 32% using alpha, and 18% when alpha and DHA or DHA/C were both taken into account. It is concluded that malabsorption of calcium is a significant risk factor for postmenopausal osteoporosis, probably because of a secondary increase in bone resorption to maintain serum calcium. The severity of the osteoporosis is directly related to the severity of the calcium malabsorption. Low serum DHA appears to represent a further risk factor, either because of its role as estrogen precursor or (possibly) because it promotes bone formation. However, the severity of the osteoporosis was not related to the serum DHA level and only weakly to the DHA/C ratio.
Publication
Journal: Journal of steroid biochemistry
July/30/1989
Abstract
The concentrations of dehydroepiandrosterone (DHEA), its sulfate (DHEAS), androstenedione (A-dione), testosterone (T) and dihydrotestosterone (DHT) have been measured before and after castration in men and two animal models, namely the rat and the guinea pig. In adult men, the pre-castration levels of plasma DHEAS and DHEA were measured at 1839 +/- 320 and 2.4 +/- 0.5 ng/ml, respectively, while in both animal models, the concentrations of these two steroids were below 0.3 ng/ml. Orchiectomy in men reduced plasma T and DHT levels from 2.9 +/- 0.1 and 0.60 +/- 0.10 to 0.42 +/- 0.21 and 0.05 +/- 0.01 ng/ml (P less than 0.01), respectively, while there was no significant effect observed on DHEAS, DHEA and A-dione levels. By contrast, castration in the rat reduced the low levels of circulating DHEA and A-dione below the detection of the radioimmunoassay (RIA) used. In castrated guinea pig, a small quantity of plasma A-dione (0.07 +/- 0.02 ng/ml) was measured while DHEA was undetectable. Moreover, in the rat and guinea pig, plasma T and DHT levels became undetectable. Following administration of the antiandrogen Flutamide for two weeks in the castrated rat and guinea pig, prostate weight was not further reduced, thus indicating that there is no significant androgenic activity left following castration of these two species. In fact, castration in the rat and guinea pig caused a decrease in prostatic levels of DHT from 4.24 +/- 0.351 and 9.42 +/- 1.43 ng/g, respectively, to undetectable levels. In men, on the other hand, the prostatic DHT levels were only inhibited from 5.24 +/- 0.59 to 2.70 +/- 1.50 ng/g, respectively. As expected, when Flutamide was administered to the rat and the guinea pig, the levels of prostatic steroids remained undetectable while, in men, the DHT content in the prostate was further reduced to undetectable values. In summary, the plasma levels of DHEAS, DHEA, delta 4-dione are markedly different between men and both animal models used and furthermore, measurements of prostatic levels of androgens suggest that the high plasma levels of these steroids are likely responsible for the presence of important amounts of DHT in human prostate after castration.
Publication
Journal: Fertility and Sterility
July/15/1998
Abstract
OBJECTIVE
To determine the effect of administering 6 months of oral postmenopausal DHEA therapy on serum DHEA, DHEAS, and T levels and on physiologic endpoints including lipoproteins and insulin-like growth factor-I (IGF-I).
METHODS
Randomized, double-blind, parallel trial.
METHODS
Academic referral practice.
METHODS
Thirteen normal-weight or overweight, healthy, nonsmoking, postmenopausal women.
METHODS
Administration of oral micronized DHEA (25 mg/d).
METHODS
Monthly fasting 23 hours postdose levels of serum DHEA, DHEAS, T, lipoproteins, IGF-I, IGF binding protein-3 (IGFBP-3), and liver function tests. Morphometric indices by dual-energy x-ray absorptiometry scan (percent body fat; lean body mass), immune indices, and insulin sensitivity.
RESULTS
Levels of DHEA, DHEAS, and T all rose into premenopausal ranges, but after 6 months, levels of DHEA and T did not differ from baseline or placebo. At 3 months, the ratio of IGF-I to IGFBP-3 rose by 36.1% +/- 12.7%, but it fell to placebo values by 6 months. High-density lipoprotein and apolipoprotein A1 levels declined.
CONCLUSIONS
Patients appeared to tolerate 6 months of DHEA therapy well. Given the small study size, no statistically significant differences in morphometric indices, immune indices, or insulin-sensitizing properties were observed, but significant attenuation of bioavailability occurred. Supplementation with DHEA increased IGF-I/IGFBP-3 levels at 3 months and decreased high-density lipoprotein and apolipoprotein A1 levels at 6 months.
Publication
Journal: Cancer Epidemiology Biomarkers and Prevention
August/29/2005
Abstract
OBJECTIVE
Hormone therapy use has been positively associated with mammographic density in several studies. However, few studies have examined the association between endogenous hormone levels and mammographic density. Therefore, we evaluated the relationship of endogenous sex hormones, insulin-like growth factor (IGF), and lipids with mammographic density in 88 overweight, postmenopausal women not taking hormone therapy.
METHODS
Percent density and dense area were evaluated as continuous measures using a computer-assisted program. We used multiple linear regression to evaluate the associations of sex hormones, IGF, and cholesterol with mammographic density, adjusting for confounders, including adiposity. We evaluated stratification by history of hormone therapy use (former versus never) and hormone therapy latency (<5 versus>> or = 5 years).
RESULTS
Among former hormone therapy users, mammographic density was inversely associated with circulating levels of estrone (P = 0.01), estradiol (P = 0.003), free estradiol (P = 0.004), testosterone (P = 0.04), free testosterone (P = 0.02), androstenedione (P < 0.001), dehydroepiandrosterone (P = 0.01), and the ratio of IGF-I to its binding protein (IGF-I/IGFBP-3; P = 0.04). We found similar associations when we limited the analyses to women who had used hormone therapy within the past 5 years. We also noted positive associations of mammographic density with total cholesterol (P = 0.03) and low-density lipoprotein (P = 0.03) among former hormone therapy users. No associations were noted among women who had never used hormone therapy.
CONCLUSIONS
These results suggest that there is an inverse relationship between endogenous sex hormones and mammographic density in postmenopausal women among former users of hormone therapy. This is not consistent with the hormone therapy literature and should be confirmed in larger studies.
Publication
Journal: Cancer Research
March/21/1999
Abstract
The A2 allele of CYP17 has been associated with polycystic ovarian syndrome, elevated levels of certain steroid hormones in premenopausal women, and increased breast cancer risk. We prospectively assessed the association between the A2 allele of CYP17 and breast cancer risk in a case-control study nested within the Nurses' Health Study cohort. We also evaluated associations between this CYP17 genotype and plasma steroid hormone levels among postmenopausal controls not using hormone replacement to assess the biological significance of this genetic variant. Women with the A2 allele were not at an increased risk of incident breast cancer [OR (odds ratio), 0.85; 95% CI (confidence interval), 0.65-1.12] or advanced breast cancer (OR, 0.84; 95% CI, 0.54-1.32). We did observe evidence that the inverse association of late age at menarche with breast cancer may be modified by the CYP17 A2 allele. The protective effect of later age at menarche was only observed among women without the A2 allele (A1/A1 genotype: for age at menarche>> or =13 versus <13; OR, 0.57; 95% CI, 0.36-0.90; A1/A2 and A2/A2 genotypes: OR, 1.05; 95% CI, 0.76-1.45; P for interaction = 0.07). Among controls, we found women with the A2/A2 genotype to have elevated levels of estrone (+14.3%, P = 0.01), estradiol (+13.8%, P = 0.08), testosterone (+8.6%, P = 0.34), androstenedione (+17.1%, P = 0.06), dehydroepiandrosterone (+14.4%, P = 0.02), and dehydroepiandrosterone sulfate (+7.2%, P = 0.26) compared with women with the A1/A1 genotype. These data suggest that the A2 allele of CYP17 modifies endogenous hormone levels, but is not a strong independent risk factor for breast cancer.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
August/4/1994
Abstract
A study was initiated to delineate the neuroendocrine characteristics of hyperandrogenic adolescent girls with the aim of discerning features that may relate to the pubertal onset of the polycystic ovarian syndrome. Thirteen 11- to 18-yr-old girls with mild to moderate signs of hyperandrogenism (HA) and increased ovarian volume and 28 age-matched normal girls were recruited for the study. LH pulsatility and FSH levels were analyzed based on serum concentrations measured with sensitive immunofluorometric assays in samples taken at 10-min intervals for 24 h under basal conditions, GnRH antagonist (Nal-Glu) suppression, and dexamethasone suppression. Adrenal and ovarian contributions to serum cortisol, dehydroepiandrosterone, androstenedione, testosterone (T), estrone (E1), estradiol (hourly), 17-hydroxypregnenolone, and 17-hydroxyprogesterone (17PO) concentrations were compared during basal and suppression conditions and after gonadotropin and adrenal stimulations by bolus GnRH (10 micrograms) and CRF (1 microgram/kg). The progression from sleep-augmented pulsatile LH secretion to higher LH levels during wake than sleep observed during normal pubertal development occurred 2 yr earlier in the HA group. The number of LH pulses was significantly higher in the HA group during both sleep and waking, whereas pulse amplitude was higher only during the awake time. Thus, mean LH was 2.0-fold higher during the awake time and only 1.6-fold higher during sleep in the HA group compared to the normal group. The elevation of FSH in HA was small relative to that of LH, resulting in an increased LH/FSH ratio (P < 0.008). The HA group had higher concentrations of 17PO (1.8-fold), androstenedione (1.9-fold), T (2.4-fold), and E1 (1.7-fold) than the normal group (all P < 0.001), with no alteration in circadian rhythm. These elevated steroid levels were significantly correlated with LH levels in the basal state and decreased in proportion to the change in LH during Nal-Glu suppression. During adrenal suppression with dexamethasone, concentrations of cortisol, dehydroepiandrosterone, and 17-hydroxypregnenolone decreased in both groups (P < 0.001), but significant suppression of 17PO, T, and E1 occurred only in the normal girls, indicating the ovarian origin of the increased levels of these steroids with enhanced expression of 17 alpha-hydroxylase activity in HA girls.(ABSTRACT TRUNCATED AT 400 WORDS)
Publication
Journal: Molecular Pharmacology
March/22/2004
Abstract
Dehydroepiandrosterone sulfotransferase (SULT2A1) is a cytosolic enzyme that mediates sulfo-conjugation of endogenous hydroxysteroids (dehydroepiandrosterone, testosterone, bile acids), and diverse xenobiotic compounds. Upon sulfonation, SULT2A1 substrates become polar and water-soluble and thus suitable for rapid excretion. SULT2A1 is abundantly expressed in the liver and intestine. Recent evidence has shown that the ligand-activated vitamin D receptor (VDR) can transcriptionally induce the xenobiotic-metabolizing cytochrome P450 enzymes. Herein, we report that VDR also targets SULT2A1 for transcriptional activation. Vitamin D stimulated endogenous SULT2A1 expression and induced transfected human, mouse, and rat SULT2A1 promoters in liver and intestinal cells upon cotransfection with VDR. An inverted repeat DNA element (IR0), located within -191 to -168 positions of mouse and rat Sult2A1, mediates VDR induction of Sult2A1. DNase1 footprinting, competition EMSA, and antibody supershift assay showed that the IR0 is a binding site for the RXR-alpha/VDR heterodimer. Point mutations within the IR0 prevented RXR/VDR binding and abolished VDR-mediated Sult2A1 induction. The IR0 element conferred VDR responsiveness on a thymidine kinase promoter. Thus, VDR-mediated nuclear signaling may be important in the phase II metabolism involving Sult2A1. The rodent Sult2A1 gene is also induced by the farnesoid X receptor (FXR) and pregnane X receptor (PXR) through the same IR0. In competition transfections, FXR or PXR inhibited VDR induction of the IR0. Competitive functional interactions among VDR, PXR, and FXR suggest that the intracellular hormonal and metabolic milieu may determine the extent to which a specific nuclear receptor pathway would influence steroid/xenobiotic metabolism using dehydroepiandrosterone sulfotransferase.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
March/10/1997
Abstract
Hyperinsulinemia contributes to the ovarian androgen overproduction and glucose intolerance of polycystic ovary syndrome (PCOS). We sought to determine whether metformin would reduce insulin levels in obese, nondiabetic women with PCOS during a period of weight maintenance and thus attenuate the ovarian steroidogenic response to the GnRH agonist leuprolide. All subjects (n = 14) had an oral glucose tolerance test, a GnRH agonist (leuprolide) test, a frequently sampled iv glucose tolerance test, graded and oscillatory glucose infusions, and a dual energy x-ray absorptiometry scan before and after treatment with metformin (850 mg, orally, three times daily for 12 weeks). With weight maintenance (body mass index: pretreatment, 39.0 +/- 7.7 kg/m2, posttreatment, 39.1 +/- 7.9 kg/m2), oral glucose tolerance, insulin sensitivity (Si; 0.87 +/- 0.82 vs. 0.74 +/- 0.63 x 10(-5) min-1/ pmol.L), and the relationship between Si and first phase insulin secretion (AIRg vs. Si) were not improved by metformin. The insulin secretory response to glucose, administered in both graded and oscillatory fashions, was likewise unaltered in response to metformin. Free testosterone levels remained about 2-fold elevated (pretreatment, 26.6 +/- 12.7 pg/mL; posttreatment, 22.4 +/- 9.8 pg/mL). Both basal and stimulated LH and FSH levels were unaffected by metformin. The mean responses to leuprolide of 17-hydroxyprogesterone (pretreatment, 387 +/- 158 ng/dL; posttreatment, 329 +/- 116 ng/dL) as well as those of the other ovarian secretory products (androstenedione, dehydroepiandrosterone, progesterone, and estradiol) were not attenuated by metformin. We conclude that hyperinsulinemia and androgen excess in obese nondiabetic women with PCOS are not improved by the administration of metformin.
Publication
Journal: Journal of the American Geriatrics Society
January/29/2007
Abstract
OBJECTIVE
To determine whether low levels of testosterone, sex hormone binding globulin (SHBG), insulin-like growth factor-1 (IGF-1), and dehydroepiandrosterone sulfate (DHEAS) and high levels of cortisol and leptin would be associated with metabolic syndrome (MS).
METHODS
Cross-sectional.
METHODS
Population-based sample of older Italian men.
METHODS
Four hundred fifty-two men aged 65 and older enrolled in the Invecchiare in Chianti (InCHIANTI) study.
METHODS
Complete data on testosterone, cortisol, DHEAS, SHBG, fasting insulin, IGF-1 and leptin. MS was defined according to Adult Treatment Panel III criteria.
RESULTS
MS was present in 73 men (15.8% of the sample). After adjusting for confounders, total testosterone (P < .05) and log (SHBG) (P < .001) were inversely associated, whereas log (leptin) was positively associated with MS (P < .001). Independent of age, log (SHBG) was positively associated with high-density lipoprotein cholesterol (P < .05) and negatively associated with abdominal obesity (P < .001) and triglycerides (P < .001). Log (leptin) was significantly associated with each component of MS. Cortisol, DHEAS, free and bioavailable testosterone, and IGF-1 were not associated with MS. Having three or more hormones in the lower (for hormones lower in MS) or the upper (for hormones higher in MS) quartile was associated with three times the risk of being affected by MS (odds ratio = 2.8, 95% confidence interval = 1.3-6.9) (P = .005), compared with not having this condition.
CONCLUSIONS
Total testosterone and SHBG are negatively and leptin is positively associated with MS in older men. Whether specific patterns of hormonal dysregulation predict the development of MS should be tested in longitudinal studies.
Publication
Journal: Human Reproduction
March/9/2008
Abstract
BACKGROUND
We evaluated carotid intima-media thickness (CIMT) as an early marker of atherosclerosis, as well as its main determinants among androgen excess, obesity and insulin resistance, in patients with polycystic ovary syndrome (PCOS).
METHODS
We selected 40 PCOS patients and 20 non-hyperandrogenic women who were similar in terms of age and grade of obesity. Complete clinical, metabolic and hormonal profiles and left common CIMT measurements were obtained.
RESULTS
Patients with PCOS presented with increased mean CIMT values when compared with controls (F = 8.575; P = 0.005), and this was independent of obesity. Five PCOS patients but no controls had increased CIMT values. CIMT correlated directly with serum total and free testosterone, androstenedione and dehydroepiandrosterone-sulfate levels and mean 24-h heart rate (HR), and inversely with the insulin sensitivity index (ISI), but no correlation was observed with the body mass index (BMI). Multiple stepwise linear regression models showed that in PCOS patients, the main determinants of CIMT were serum total testosterone or androstenedione concentrations, with no influence of ISI or the mean 24-h HR.
CONCLUSIONS
Compared with control women, PCOS patients present with an increased CIMT, independent of obesity and related directly to androgen excess; this suggests that hyperandrogenism is associated with atherosclerosis and cardiovascular risk in these women.
Publication
Journal: Clinical Cancer Research
October/23/2012
Abstract
OBJECTIVE
Treatment with abiraterone (abi) acetate prolongs survival in castration-resistant prostate cancer (CRPC). Resistance to abi invariably occurs, probably due in part to upregulation of steroidogenic enzymes and/or other mechanisms that sustain dihydrotestosterone (DHT) synthesis, which raises the possibility of reversing resistance by concomitant inhibition of other required steroidogenic enzymes. On the basis of the 3β-hydroxyl, Δ(5)-structure, we hypothesized that abi also inhibits 3β-hydroxysteroid dehydrogenase/isomerase (3βHSD), which is absolutely required for DHT synthesis in CRPC, regardless of origins or routes of synthesis.
METHODS
We tested the effects of abi on 3βHSD activity, androgen receptor localization, expression of androgen receptor-responsive genes, and CRPC growth in vivo.
RESULTS
Abi inhibits recombinant 3βHSD activity in vitro and endogenous 3βHSD activity in LNCaP and LAPC4 cells, including conversion of [(3)H]-dehydroepiandrosterone (DHEA) to Δ(4)-androstenedione, androgen receptor nuclear translocation, expression of androgen receptor-responsive genes, and xenograft growth in orchiectomized mice supplemented with DHEA. Abi also blocks conversion of Δ(5)-androstenediol to testosterone by 3βHSD. Abi inhibits 3βHSD1 and 3βHSD2 enzymatic activity in vitro; blocks conversion from DHEA to androstenedione and DHT with an IC(50) value of less than 1 μmol/L in CRPC cell lines; inhibits androgen receptor nuclear translocation; expression of TMPRSS2, prostate-specific antigen, and FKBP5; and decreases CRPC xenograft growth in DHEA-supplemented mice.
CONCLUSIONS
We conclude that abi inhibits 3βHSD-mediated conversion of DHEA to active androgens in CRPC. This second mode of action might be exploited to reverse resistance to CYP17A1 inhibition at the standard abi dose by dose-escalation or simply by administration with food to increase drug exposure.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
September/16/2007
Abstract
BACKGROUND
Anorexia nervosa and normal-weight hypothalamic amenorrhea are characterized by hypogonadism and hypercortisolemia. However, it is not known whether these endocrine abnormalities result in reductions in adrenal and/ or ovarian androgens or androgen precursors in such women, nor is it known whether relative androgen deficiency contributes to abnormalities in bone density and body composition in this population.
OBJECTIVE
Our objective was to determine whether endogenous androgen and dehydroepiandrosterone sulfate (DHEAS) levels: 1) are reduced in women with anorexia nervosa and normal-weight hypothalamic amenorrhea, 2) are reduced further by oral contraceptives in women with anorexia nervosa, and 3) are predictors of weight, body composition, or bone density in such women.
METHODS
We conducted a cross-sectional study at a general clinical research center.
METHODS
A total of 217 women were studied: 137 women with anorexia nervosa not receiving oral contraceptives, 32 women with anorexia nervosa receiving oral contraceptives, 21 normal-weight women with hypothalamic amenorrhea, and 27 healthy eumenorrheic controls.
METHODS
Testosterone, free testosterone, DHEAS, bone density, fat-free mass, and fat mass were assessed.
RESULTS
Endogenous total and free testosterone, but not DHEAS, were lower in women with anorexia nervosa than in controls. More marked reductions in both free testosterone and DHEAS were observed in women with anorexia nervosa receiving oral contraceptives. In contrast, normal-weight women with hypothalamic amenorrhea had normal androgen and DHEAS levels. Lower free testosterone, total testosterone, and DHEAS levels predicted lower bone density at most skeletal sites measured, and free testosterone was positively associated with fat-free mass.
CONCLUSIONS
Androgen levels are low, appear to be even further reduced by oral contraceptive use, and are predictors of bone density and fat-free mass in women with anorexia nervosa. Interventional studies are needed to confirm these findings and determine whether oral contraceptive use, mediated by reductions in endogenous androgen levels, is deleterious to skeletal health in such women.
Publication
Journal: British Journal of Psychiatry
November/18/2012
Abstract
BACKGROUND
The 'extreme male brain' theory suggests that autism spectrum disorder (ASD) is an extreme variant of male intelligence. However, somewhat paradoxically, many individuals with ASD display androgynous physical features regardless of gender.
OBJECTIVE
To assess physical measures, supposedly related to androgen influence, in adults with and without ASD.
METHODS
Serum hormone levels, anthropometry, the ratio of 2nd to 4th digit length (2D:4D) and psychiatric symptomatology were measured in 50 adults with high-functioning ASD and age- and gender-matched neurotypical controls. Photographs of face and body, as well as voice recordings, were obtained and assessed with respect to gender coherence, blindly and independently, by eight assessors.
RESULTS
Women with ASD had higher total and bioactive testosterone levels, less feminine facial features and a larger head circumference than female controls. Men in the ASD group were assessed as having less masculine body characteristics and voice quality, and displayed higher (i.e. less masculine) 2D:4D ratios, but similar testosterone levels to controls. Androgynous facial features correlated strongly and positively with autistic traits measured with the Autism-Spectrum Quotient in the total sample. In males and females with ASD dehydroepiandrosterone sulfate did not decrease with age, in contrast to the control group.
CONCLUSIONS
Women with ASD had elevated testosterone levels and several masculinised characteristics compared with controls, whereas men with ASD displayed several feminised characteristics. Our findings suggest that ASD, rather than being characterised by masculinisation in both genders, may constitute a gender defiant disorder.
Publication
Journal: Brain Research
September/24/1998
Abstract
The ability of the nitric oxide (NO) synthase inhibitor, NG-nitro-l-arginine methyl ester (L-NAME), to modulate the attenuating effects of neurosteroids on the aging- and NMDA receptor antagonist dizocilpine-induced learning impairment, was tested in mice using two different behavioral models of long-term memory. The performance of aged mice (16 months old) in step-down type of passive-avoidance and elevated plus-maze paradigms was significantly impaired compared to that of young mice (3 months old). Neurosteroids pregnenolone sulfate (PS) and dehydroepiandrosterone sulfate (DHEAS), at 1-20 mg/kg, s.c., significantly improved the passive-avoidance and plus-maze performances in aged mice. Neurosteroids PS and DHEAS, at doses 1-20 mg/kg, s.c., significantly attenuated dizocilpine (0.1 mg/kg, i.p.)-induced amnesia, without producing any promnestic effects alone in adult mice. In both cognitive tasks, the effects exhibited by the neurosteroids tested had a bell-shaped curve. Preadministration of L-NAME (10 and 20 mg/kg, i.p.), at doses that did not disrupt cognition alone in either young or aged mice, significantly blocked the beneficial and antiamnesic effects of neurosteroids PS (5 mg/kg) and DHEAS (10 mg/kg). A selective action of L-NAME on the effects of neurosteroids was indicated, since the effects of L-NAME were completely reversed by L-arginine (300 mg/kg, i.p.), a competitive substrate for NO synthase. Neither L-NAME nor L-arginine alone affected the antinociception, locomotor activity or rota-rod performance of young or aged mice. These observations suggest that a NO-dependent mechanism may be involved in the beneficial and antiamnesic effects of neurosteroids PS and DHEAS on the aging- and dizocilpine-induced impairment of learning and memory processes.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
February/9/2005
Abstract
Racial origin and family history of type 2 diabetes impact upon the risk of developing impaired glucose tolerance (IGT) and type 2 diabetes, both of which are common in women with polycystic ovary syndrome (PCOS). We examined the effects of race and family history of type 2 diabetes on the risk of IGT and type 2 diabetes in a large cohort of women with PCOS. Data obtained at baseline were analyzed from 408 premenopausal women with PCOS. Multivariate linear regression models were used to assess the impact of race (white, black, and other) and family history of type 2 diabetes on body mass index, waist circumference, and waist to hip ratio; glycemic measures (glucose and insulin levels obtained during a standard 75-g oral glucose tolerance test, fasting glucose to insulin ratio, and homeostasis model assessment model of insulin resistance derived from fasting levels of glucose and insulin), hemoglobin A(1c), and SHBG, and dehydroepiandrosterone sulfate levels. Sixteen (4%) of the 408 patients had type 2 diabetes, 94 (23%) had IGT, and the remaining 298 (73%) had normal glucose tolerance. A history of type 2 diabetes in either parent (FHxPOS) was present in seven (44%) of the 16 diabetic women with PCOS, 37 (39%) of the 94 women with IGT, and 62 (21%) of those with normal glucose tolerance (P < 0.01, by chi(2) test). The prevalences of IGT and type 2 diabetes were significantly higher in FHxPOS PCOS women compared with FHxNEG PCOS women, IGT evident in 37 (35%) FHxPOS compared with 57 (19%) FHxNEG women, and type 2 diabetes evident in seven (7%) FHxPOS compared with nine (3%) FHxNEG women. Among the 392 nondiabetic subjects, after adjustment for the effects of race, FHxPOS differed significantly from FHxNEG patients in having a higher mean waist to hip ratio, hemoglobin A(1c) level, 2-h glucose level, fasting glucose and insulin levels, glucose to insulin ratio, homeostasis model assessment model of insulin resistance, and areas under the glucose and insulin curves during the oral glucose tolerance test. A family history of type 2 diabetes was present with a significantly greater frequency among women with PCOS who had IGT or type 2 diabetes compared with those with normal glucose tolerance. Conversely, a family history of type 2 diabetes in a first-degree relative was associated with a significantly higher risk for IGT or type 2 diabetes in women with PCOS. Even among nondiabetic women with PCOS, a positive family history of type 2 diabetes was strongly associated with metabolic characteristics associated with an increased risk for type 2 diabetes. Finally, the fasting glucose concentration was poorly associated with 2-h glucose concentrations among PCOS women with IGT, suggesting that the fasting glucose concentration is inadequate to predict the presence of IGT in PCOS.
Publication
Journal: Journal of the American College of Cardiology
October/29/1997
Abstract
OBJECTIVE
We sought to assess the possible relations between clinical severity of chronic heart failure and catabolic factors, specifically tumor necrosis factor (TNF), soluble TNF receptors 1 and 2 (sTNFR-1 and sTNFR-2), cortisol, testosterone and dehydroepiandrosterone (DHEA).
BACKGROUND
Chronic heart failure is associated with loss of muscle bulk that may be related to alteration of the balance between catabolism and anabolism.
METHODS
Sixty-three patients (average age +/- SD 60.4 +/- 11.3 years) with stable chronic heart failure and 20 control subjects aged 52.8 +/- 11.4 years were studied. We measured body mass index (BMI) and obtained maximal incremental exercise testing with metabolic gas exchange measurements and measurements of venous levels of TNF, sTNFR-1 and sTNFR-2, cortisol and DHEA.
RESULTS
There was no difference in total TNF-alpha levels between patients and control subjects (9.76 +/- 8.59 vs. 6.84 +/- 2.7 pg/ml). sTNFR-1 (128.9 +/- 84.5 vs. 63.6 +/- 23.3 pg/ml, p < 0.003) and sTNFR-2 (250.1 +/- 109.5 vs. 187.9 +/- 92.2 pg/ml, p = 0.03) were higher in patients. DHEA was lower in patients (9.88 +/- 6.94 vs. 15.64 +/- 8.33 nmol/liter, p = 0.004). The ratio of log cortisol to log DHEA correlated with log TNF level (r = 0.50, p < 0.001 for the patients alone; r = 0.48, p < 0.001 for the group as a whole). Peak oxygen consumption correlated with both sTNFR-1 and sTNFR-2 (r = -0.51, p < 0.001 and r = -0.39, p < 0.001, respectively). There was a negative correlation between BMI and TNF levels (r = -0.43, p < 0.001 for the patients) and the cortisol/DHEA ratio (r = -0.32, p = 0.01 for the patients).
CONCLUSIONS
There is an increase in TNF and its soluble receptors in chronic heart failure. This increase is associated with a rise in the cortisol/DHEA (catabolic/anabolic) ratio. These changes correlate with BMI and clinical severity of heart failure, suggesting a possible etiologic link.
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