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Publication
Journal: Neurology
January/13/2005
Abstract
BACKGROUND
Men with epilepsy have reduced fertility, and antiepileptic drugs may affect semen quality. Moreover, animal studies suggest that valproate (VPA) may be associated with testicular atrophy.
OBJECTIVE
To evaluate reproductive function in men with epilepsy.
METHODS
Sixty men with epilepsy and 41 control men were evaluated for their reproductive health. Fifteen men were taking carbamazepine (CBZ) and 18 men oxcarbazepine (OXC) for partial epilepsy, and 27 men were taking VPA for generalized epilepsy. Reproductive hormones were assayed from serum samples, semen analysis and ultrasonography of the testicles were performed, and testicular volume was calculated.
RESULTS
Men on CBZ had low serum dehydroepiandrosterone sulfate concentrations (p < 0.001), and men on VPA had high concentrations of serum androstenedione (p < 0.001). The frequency of morphologically abnormal sperm was higher among CBZ-treated (p < 0.01), OXC-treated (p < 0.05), and VPA-treated men (p < 0.01) than among the control men. Moreover, both CBZ and VPA were associated with poor motility of sperm (p < 0.05). In addition, the frequency of abnormally low sperm concentration was high in men on CBZ (p < 0.001), and the frequency of any sperm abnormality was high in men on VPA (p < 0.01). The VPA-treated men with abnormal sperm had smaller testicular volumes than the control men (p = 0.003).
CONCLUSIONS
CBZ, OXC, and VPA are associated with sperm abnormalities in men with epilepsy. In addition, VPA-treated men with generalized epilepsy who have abnormal sperm may have reduced testicular volume.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
November/14/2000
Abstract
In recent years, adrenal function and aging has been the subject of intense interest. This cross-sectional study examines age and gender differences in plasma levels of cortisol, dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEAS), and the molar ratio of cortisol/DHEAS in 50-89-yr-old community-dwelling adults. Plasma hormone levels were assayed in samples obtained between 0730 h and 1100 h from 857 men and 735 nonestrogen-using, postmenopausal women. Hormone levels were stratified by 10-yr age groups and compared by two-factor (gender and age) ANOVA. Overall, age and BMI-adjusted DHEA and DHEAS [collectively DHEA(S)] levels were 40% lower and cortisol levels 10% higher in women than men, resulting in a 1.7-fold higher cortisol/DHEAS molar ratio for women (both, P < 0.001). Cortisol levels increased progressively (20% overall) with age in both men and women (both, P < 0.01). Although DHEA(S) levels declined 60% and the cortisol/DHEAS ratio increased 3-fold across the 40-yr age range for both men and women (all P < 0.001), the pattern of the change differed (all P < 0.01 for interaction). For men, DHEA(S) fell in a curvilinear fashion, with the degree of change decreasing with each decade. In contrast, DHEA(S) levels in women fell 40% from the 50s to 60s, were unvarying from 60-80 yr of age, and declined an additional 18% in the 80s. The cortisol/DHEAS ratio increased in a linear fashion for men, but was flat during the 60-80-yr age range for women. Despite these differences in the effect of aging, levels of DHEA(S) remained lower and cortisol and the cortisol/DHEAS ratio higher, in women than men throughout the 50-89-yr age range. These results were independent of adiposity, smoking, and alcohol consumption. In summary, among older, healthy adults DHEA(S) levels are lower and cortisol levels higher in women than men. The age-related decline in adrenal androgens persists into advanced age for both men and women, but exhibits a sexually dimorphic pattern. In contrast, cortisol levels in men and women show a parallel, linear increase with aging. These findings may have important implications for a host of age-related processes that exhibit gender differences, including brain function, bone metabolism, and cardiovascular disease.
Publication
Journal: Endocrinology
June/3/2007
Abstract
Steroids in brain arise from the peripheral endocrine glands and local synthesis. In traumatic brain injury (TBI), the endogenous circulating hormones at the time of injury are important for neuroprotection. In particular, pseudopregnant females recover better than males from TBI. We investigated the effect of pseudopregnancy and TBI on steroid levels in plasma and in three brain regions (within, adjacent, and distal to the lesion site), 6 and 24 h after prefrontal cortex injury. The following steroids were analyzed by gas chromatography/mass spectrometry: pregnenolone, progesterone, 5alpha-dihydroprogesterone, 3alpha,5alpha-tetrahydroprogesterone, 3beta,5alpha-tetrahydroprogesterone, dehydroepiandrosterone, Delta(4)-androstenedione, testosterone, 5alpha-dihydrotestosterone, 3alpha,5alpha-tetrahydrotestosterone, 3beta,5alpha-tetrahydrotestosterone, and 17beta-estradiol. Corticosterone was assayed in plasma to account for stress in the rats. We found different steroid profiles in brain and plasma of male and pseudopregnant female rats and specific profile changes after TBI. In sham-operated pseudopregnant females, much higher levels of progesterone, 5alpha-dihydroprogesterone, 3alpha,5alpha-tetrahydroprogesterone, and 3beta,5alpha-tetrahydroprogesterone were measured in both brain and plasma, compared with sham-operated males. Plasma levels of corticosterone were high in all groups, indicating that the surgeries induced acute stress. Six hours after TBI, the levels of pregnenolone, progesterone, and 5alpha-dihydroprogesterone increased, and those of testosterone decreased in male brain, whereas levels of 5alpha-dihydroprogesterone and 3beta,5alpha-tetrahydroprogesterone increased in brain of pseudopregnant female rats. Plasma levels of 5alpha-dihydroprogesterone did not change after TBI, suggesting a local activation of the 5alpha-reduction pathway of progesterone in both male and pseudopregnant female brain. The significant increase in neurosteroid levels in the male brain after TBI is consistent with their role in neuroprotection. In pseudopregnant females, high levels of circulating progestagens may provide protection against TBI.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
July/1/2009
Abstract
BACKGROUND
Serum levels of the sex steroid prohormones dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) decline upon aging and are reduced in primary Sjogren's syndrome.
OBJECTIVE
Our aim was to investigate: 1) effects of 50 mg oral DHEA/day on changes in serum levels of DHEA and 12 of its metabolites; 2) relationships between steroid levels and disease characteristics; and 3) whether these parameters were influenced by DHEA.
METHODS
Twenty-three postmenopausal women with primary Sjogren's syndrome and subnormal levels of DHEA-S were included in a randomized, 9-month, controlled, double blind crossover study. Liquid chromatography/mass spectrometry (MS)/MS and gas chromatography/MS were used to measure the sex steroids. Anti-SS-A/Ro and/or anti-SS-B/La, salivary gland focus score, salivary flow rates, dry mouth and eye symptoms, and routine laboratory tests were assessed.
RESULTS
Baseline erythrocyte sedimentation rate was inversely correlated with testosterone (Testo), dihydrotestosterone, and DHEA-S (rs = -0.42, -0.45, and -0.58, respectively). Dry mouth symptoms correlated with low Testo and androstenedione, whereas dry eyes correlated with low estrogens, most strongly estrone (rs = -0.63). Presence of anti-SS-A and/or anti-SS-B was independently associated with low estradiol (area under the receiver operating characteristic curve, 0.82). All metabolites increased during DHEA but not during placebo. The relative increases were less for estrogens and Testo compared to dihydrotestosterone and glucuronidated androgen metabolites. Dry mouth symptoms decreased during DHEA therapy.
CONCLUSIONS
Disease manifestations in primary Sjogren's syndrome were associated with low sex hormone levels, dry mouth symptoms with low androgens, and dry eyes with low estrogens. Exogenous DHEA was preferentially transformed into androgens rather than into estrogens.
Publication
Journal: Archives of general psychiatry
March/3/2003
Abstract
BACKGROUND
Negative symptoms of schizophrenia are a prominent feature of the illness, and frequently remain refractory to treatment. Dehydroepiandrosterone (DHEA), along with its sulfated form, DHEA-S, is an important circulating neurosteroid with several vital neurophysiological functions, including the regulation of neuronal excitability and function.
OBJECTIVE
Since the administration of DHEA has demonstrated improvement in mood, sense of well-being, interest, activity, and energy in several subpopulations, we investigate the efficacy of DHEA in the management of the negative symptoms of schizophrenia.
METHODS
Thirty DSM-IV-diagnosed schizophrenic patients with prominent negative symptoms (inpatients in a large referral state hospital) were randomized to receive either DHEA or placebo in double-blind fashion, in addition to regular antipsychotic medication, dose-stabilized prior to study entry. The DHEA was titrated up to a dose of 100 mg in divided doses during 6 weeks.
RESULTS
Results indicated significant improvement in negative symptoms (P<.001), as well as in depressive (P<.05) and anxiety (P<.001) symptoms in individuals receiving DHEA. This effect was especially noted in women. The improvement in negative symptoms was independent of improvement in depression. No differences were noted on the positive symptom subscale of the Positive and Negative Syndrome Scale (PANSS) or on the total PANSS score as compared with placebo. Subjects receiving DHEA demonstrated a significant increase in DHEA (P<.05) and DHEA-S (P<.01) plasma levels, without changes in cortisol levels. Increases in DHEA and plasma DHEA-S levels were correlated with improvement in negative symptoms (P<.05), but not with improvement in depressive and anxiety symptoms. No obvious adverse effects were experienced by participating subjects.
CONCLUSIONS
Our preliminary observations report for the first time in double-blind fashion the efficacy of DHEA augmentation in the management of negative, depressive, and anxiety symptoms of schizophrenia. The findings from this study raise important issues regarding the role of neurosteroids in general, and DHEA in particular, in the ongoing symptomatology and pharmacotherapy of schizophrenia.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
September/10/2003
Abstract
Cytochrome P450c17 catalyzes both 17alpha-hydroxylation and 17,20-lyase conversion of 21-carbon steroids to 19-carbon precursors of sex steroids. P450c17 can mediate testosterone biosynthesis via the conversion of pregnenolone to dehydroepiandrosterone (the delta(5) pathway) or via conversion of progesterone to androstenedione (the delta(4) pathway). In many species, the 17, 20-lyase activity of P450c17 for one pathway dominates, reflecting the preferred steroidogenic pathway of that species. All studies of recombinant human P450c17 and of human adrenal microsomes have found high 17, 20-lyase activity only in the delta(5) pathway. Because the 17, 20-lyase activities in both the delta(4) and delta(5) pathways for testicular P450c17 have not been directly compared, however, it is not known if the delta(5) pathway dominates in the human testis. To resolve this issue, we assayed the conversion of 17alpha-hydroxypregnenolone to dehydroepiandrosterone (delta(5) 17, 20-lyase activity) and of 17alpha-hydroxyprogesterone to androstenedione (delta(4) 17, 20-lyase activity) by human fetal testicular microsomes. We obtained apparent Michaelis constant (K(m)) and maximum velocity (V(max)) values of 1.0 microM and 0.73 pmol.min(-1). microg(-1) for delta(5) 17, 20-lyase activity and of 3.5 microM and 0.23 pmol.min(-1). microg(-1) for delta(4) 17, 20-lyase activity. Catalytic efficiencies, expressed as the ratio V(max)/K(m), were 0.73 and 0.066 for the delta(5) and delta(4) reactions, respectively, indicating 11-fold higher preference for the delta(5) pathway. We conclude that the majority of testosterone biosynthesis in the human testis proceeds through the conversion of pregnenolone to dehydroepiandrosterone via the delta(5) pathway.
Publication
Journal: Journal of the American College of Cardiology
November/13/2018
Abstract
BACKGROUND
Higher androgen and lower estrogen levels are associated with cardiovascular disease (CVD) risk factors in women. However, studies on sex hormones and incident CVD events in women have yielded conflicting results.
OBJECTIVE
The authors assessed the associations of sex hormone levels with incident CVD, coronary heart disease (CHD), and heart failure (HF) events among women without CVD at baseline.
METHODS
The authors studied 2,834 post-menopausal women participating in the MESA (Multi-Ethnic Study of Atherosclerosis) with testosterone, estradiol, dehydroepiandrosterone, and sex hormone binding globulin (SHBG) levels measured at baseline (2000 to 2002). They used Cox hazard models to evaluate associations of sex hormones with each outcome, adjusting for demographics, CVD risk factors, and hormone therapy use.
RESULTS
The mean age was 64.9 ± 8.9 years. During 12.1 years of follow-up, 283 CVD, 171 CHD, and 103 HF incident events occurred. In multivariable-adjusted models, the hazard ratio (95% confidence interval [CI]) associated with 1 SD greater log-transformed sex hormone level for the respective outcomes of CVD, CHD, and HF were as follows: total testosterone: 1.14 (95% CI: 1.01 to 1.29), 1.20 (95% CI: 1.03 to 1.40), 1.09 (95% CI: 0.90 to 1.34); estradiol: 0.94 (95% CI: 0.80 to 1.11), 0.77 (95% CI: 0.63 to 0.95), 0.78 (95% CI: 0.60 to 1.02); and testosterone/estradiol ratio: 1.19 (95% CI: 1.02 to 1.40), 1.45 (95% CI: 1.19 to 1.78), 1.31 (95% CI: 1.01 to 1.70). Dehydroepiandrosterone and SHBG levels were not associated with these outcomes.
CONCLUSIONS
Among post-menopausal women, a higher testosterone/estradiol ratio was associated with an elevated risk for incident CVD, CHD, and HF events, higher levels of testosterone associated with increased CVD and CHD, whereas higher estradiol levels were associated with a lower CHD risk. Sex hormone levels after menopause are associated with women's increased CVD risk later in life.
Publication
Journal: Reproductive BioMedicine Online
December/15/2010
Abstract
Dehydroepiandrosterone (DHEA) has been reported to improve oocyte/embryo yields and oocyte/embryo quality in women with diminished ovarian reserve. Whether DHEA objectively improves ovarian reserve is, however, unknown. This study investigated 120 consecutive patients with diminished ovarian reserve, supplemented for 30-120 days (mean 73+/-27) with DHEA (25mg three times daily). Anti-Müllerian hormone (AMH) concentrations were determined in relationship to DHEA supplementation using linear regression and, longitudinally, by examining interaction between days of DHEA treatment and pregnancy success in respect to changes in AMH. AMH concentrations significantly improved after DHEA supplementation over time (P=0.002). Women under age 38 years demonstrated higher AMH concentrations and improved AMH concentrations more than older females. AMH improved longitudinally by approximately 60% (P<0.0002). Women reaching IVF experienced a 23.64% clinical pregnancy rate and conceiving women showed significantly improved AMH concentrations compared with those who did not (P=0.001). DHEA supplementation, thus, significantly improved ovarian reserve in parallel with longer DHEA use and was more pronounced in younger women.
Publication
Journal: Arthritis and rheumatism
May/5/1987
Abstract
The high ratio of women with systemic lupus erythematosus (SLE) has remained unexplained, despite the recent description of metabolic abnormalities of estrogen and androgen metabolism. Alterations of steroid metabolism in patients with SLE could be important in the pathogenesis of this disease, since it has been reported that gonadal steroids modulate the immune system. Moreover, research with inbred lupus mice has shown that estrogens have adverse effects on the disease in both sexes, whereas androgen therapy or oophorectomy is protective in females. Recently, the finding of elevated testosterone oxidation at C-17 in females with SLE suggested that plasma androgen levels in males and females with SLE should be examined more closely. We studied the varying degrees of clinical activity, with regard to plasma levels of 4 significant androgens: testosterone, androstenedione, dehydroepiandrosterone, and dehydroepiandrosterone sulfate in a series of 5 male and 42 female SLE patients. Decreased levels of all androgens were observed in women with SLE. The lowest levels of plasma androgens were found in female patients who had active disease, as determined by laboratory and clinical assessment. These data support the fact that specific abnormalities of androgen metabolism in the female are associated with SLE, and may contribute in some way to morbidity and mortality. More importantly, these data may have implications for future therapeutic regimens based on male hormone replacement.
Publication
Journal: American Journal of Obstetrics and Gynecology
February/19/2003
Abstract
OBJECTIVE
The purpose of this study was to determine whether treatment with the immune modulators dexamethasone or interleukin-10 prevents interleukin-1beta-induced uterine contractions in a nonhuman primate model.
METHODS
Thirteen chronically instrumented rhesus monkeys at 135 +/- 1 days of gestation (term, 167 days) received one of three interventions: (1) intra-amniotic interleukin-1beta (10 microg) infusion with maternal dexamethasone (1 mg/kg) intravenously every 6 hours for 1 day before interleukin-1beta and for 2 days thereafter (n = 4), (2) intra-amniotic interleukin-1beta infusion with maternal interleukin-10 (25 microg/kg) given intravenously and 100 microg interleukin-10 given intra-amniotically before the interleukin-1beta and continued every 8 hours for 3 days (n = 5), and (3) intra-amniotic interleukin-1beta administered alone (n = 5). Uterine activity was monitored continuously and quantified as the hourly contraction area (millimeters of mercury times seconds per hour) in all groups until delivery. Amniotic fluid was sampled for leukocyte counts and assayed for prostaglandins E(2) and F(2)alpha, cytokines interleukin-1beta, interleukin-6, interleukin-8, tumor necrosis factor-alpha, interleukin-10, and interleukin-1 receptor antagonist by specific assays. Maternal and fetal blood were assayed for cortisol, dehydroepiandrosterone sulfate, and estradiol.
RESULTS
Interleukin-1beta infusion in the absence of immune modulators resulted in an increase in uterine activity and amniotic fluid proinflammatory cytokines, prostaglandins, and leukocytes. Dexamethasone and interleukin-10 treatment significantly reduced interleukin-1beta-induced uterine contractility (P <.05) and amniotic fluid prostaglandins (P <.05) but not interleukin-8 or interleukin-1 receptor antagonist. Amniotic fluid interleukin-6 and maternal and fetal cortisol, dehydroepiandrosterone sulfate, and estradiol concentrations were reduced by dexamethasone (P <.05), whereas tumor necrosis factor-alpha levels and leukocyte counts were attenuated by interleukin-10 treatment (P <.05). An inverse relationship was noted between amniotic fluid interleukin-10 concentrations and interleukin-1beta-induced uterine activity (r = -0.74, P <.05).
CONCLUSIONS
Dexamethasone and interleukin-10 exert similar inhibitory effects on interleukin-1beta-induced uterine activity, which appears to be mediated by a decrease in prostaglandin production. Reduced estrogen biosynthesis or suppression of tumor necrosis factor-alpha and leukocyte migration may contribute to the tocolytic actions of dexamethasone and interleukin-10, respectively. Dexamethasone and interleukin-10 are likely to be useful adjuncts in the treatment of preterm labor that is associated with inflammation or infection.
Publication
Journal: Endocrine Reviews
December/28/2004
Abstract
Androgens have important physiological effects in women. Postmenopausal androgen replacement, most commonly as testosterone therapy, is becoming increasingly widespread. This is despite the lack of clear guidelines regarding the diagnosis of androgen insufficiency, optimal therapeutic doses, and long-term safety data. With respect to the breast specifically, there is the potential for exogenous testosterone to exert either androgenic or indirect estrogenic actions, with the latter potentially increasing breast cancer risk. In experimental studies, androgens exhibit growth-inhibitory and apoptotic effects in some, but not all, breast cancer cell lines. Differing effects between cell lines appear to be due primarily to variations in concentrations of specific coregulatory proteins at the receptor level. In rodent breast cancer models, androgen action is antiproliferative and proapoptotic, and is mediated via the androgen receptor, despite the potential for testosterone and dehydroepiandrosterone to be aromatized to estrogen. The results from studies in rhesus monkeys suggest that testosterone may serve as a natural endogenous protector of the breast and limit mitogenic and cancer-promoting effects of estrogen on mammary epithelium. Epidemiological studies have significant methodological limitations and provide inconclusive results. The strongest data for exogenous testosterone therapy comes from primate studies. Based on such simulations, inclusion of testosterone in postmenopausal estrogen-progestin regimens has the potential to ameliorate the stimulating effects of combined estrogen-progestin on the breast. Research addressing this is warranted; however, the number of women that would be required for an adequately powered randomized controlled trial renders such a study unlikely.
Publication
Journal: Journal of Nutrition
March/17/1998
Abstract
Sarcopenia of aging is not explained entirely on the basis of age-associated reduced physical activity. Progressive neuromuscular changes and diminishing anabolic hormone levels are thought to contribute to the pathogenesis of sarcopenia. Decline in muscle mass indicates a decline in muscle protein content. Recent studies demonstrated an age-related decline in synthesis rate of mixed muscle proteins, myosin heavy chain and mitochondrial protein. Reductions in myosin heavy chain and mitochondrial protein synthesis rates have been correlated with age-associated decrements in muscle strength and aerobic exercise tolerance, respectively. These changes have been reported as early as 50 y of age and are related to the decline in insulin-like growth factor (IGF)-I, testosterone and dehydroepiandrosterone (DHEA)-sulfate. The declining ability to remodel these important muscle proteins may therefore play a role in the development of muscle wasting, metabolic abnormalities and impaired physical functioning seen in old age.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
September/1/1998
Abstract
Estrogens produced by the placenta play a pivotal role in the endocrine control of pregnancy and induce many of the key changes involved in parturition. The placentae of humans and higher primates use the C19 androgen dehydroepiandrosterone sulfate (DHEA-S) supplied by the fetal adrenals as the principal substrate for estrogen synthesis. Thus, secretion of androgens by the fetal adrenals may be central to the process of primate parturition. The timing of human parturition also is correlated with placental CRH concentrations in the maternal circulation. Because the mechanisms that regulate DHEA-S production by the fetal adrenals are incompletely understood, we examined whether there is a functional relationship between CRH and steroid production by human fetal adrenal cortical cells. Using Northern blot analysis, we detected messenger RNA transcripts (2.7 kb) encoding the type-1 CRH receptor in total RNA extracted from midgestation human fetal adrenals, suggesting that the fetal adrenal cortex may be directly responsive to CRH. To test this, primary cultures of human fetal adrenal cortical cells were exposed to human CRH. Human CRH increased DHEA-S production by cultured human fetal adrenal cortical cells in a dose-dependent fashion, with an ED50 of 10-100 pmol/L. Human CRH was as effective as ACTH at stimulating DHEA-S production; however, it was 70% less potent than ACTH at stimulating cortisol production, indicating that its actions were preferentially directed toward increasing DHEA-S synthesis. Consistent with this thesis, we found that CRH increased abundance of messenger RNA encoding cytochrome P450 cholesterol side-chain cleavage and 17alpha-hydroxylase/17,20 lyase but not 3beta-hydroxysteroid dehydrogenase in adrenal cells. CRH did not alter cell number, indicating that it is not mitogenic for fetal adrenal cortical cells. These data demonstrate a direct functional interaction between CRH and the fetal adrenal. Therefore, placental CRH production, which rises exponentially during human pregnancy, may play a key role in promoting DHEA-S production by the fetal adrenals, which could lead to increasing placental estrogen synthesis and contribute to the process of parturition in humans.
Publication
Journal: Neuroscience
May/6/1999
Abstract
Glucocorticoids are toxic to hippocampal neurons. We report here that the steroid dehydroepiandrosterone protects neurons of primary hippocampal cultures against the toxic effects of corticosterone. Corticosterone (20-500 nM) added for 24h to primary cultures of embryonic day 18 rat hippocampus resulted in significant neurotoxicity. Dissociated cells were grown for at least 10 days, initially in serum-containing medium, but serum was removed before adding steroids for 24 h. Neurotoxicity was measured by counting the number of cells stained either for beta-tubulin III or glial fibrillary acidic protein. Corticosterone-induced toxicity was prevented by co-treatment of the cultures with dehydroepiandrosterone (20-500 nM). Dehydroepiandrosterone on its own had little effect, though the highest concentration used (500 nM) was mildly toxic. Immunohistochemical studies on the nuclear translocation of a range of stress-activated protein kinases showed that stress-activated protein kinases 1, 2, 3 and 4 were all translocated by 10 min exposure to corticosterone (100 nM). Dehydroepiandrosterone (100 nM) attenuated the translocation of stress-activated protein kinase 3, but not the others. These experiments show that dehydroepiandrosterone has potent anti-glucocorticoid actions on the brain, and can protect hippocampal neurons from glucocorticoid-induced neurotoxicity. This protective action may involve stress-activated protein kinase 3-related intracellular pathways, though direct evidence for this has still to be obtained.
Publication
Journal: Seminars in Reproductive Medicine
May/3/2005
Abstract
The biosynthesis of dehydroepiandrosterone (DHEA) from cholesterol involves only two enzymes, both cytochrome P450s. The conversion of cholesterol to pregnenolone is mediated by cholesterol side-chain cleavage enzyme (CYP11A1), which is found in the mitochondria. The cleavage of pregnenolone to DHEA requires both the 17alpha-hydroxylase and 17,20-lyase activities of CYP17, which is found in the endoplasmic reticulum. These conversions require pairs of electron transfer proteins or redox partners, which are adrenodoxin and adrenodoxin reductase for CYP11A1 and cytochrome P450-oxidoreductase and cytochrome b5 for CYP17. In addition, the steroidogenic acute regulatory (StAR) protein regulates the flux of cholesterol into the biosynthetic pathway and represents the mechanism of acute regulation. Finally, in addition to possessing CYP11A1 and CYP17, it is equally important that a steroidogenic cell not contain other enzymes that drain the flux of pregnenolone to DHEA. These characteristics are illustrated by the fetal adrenal cortex and the zona reticularis, which are dedicated to the synthesis of DHEA and DHEA-sulfate.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
June/12/1991
Abstract
Stimulation of androgen-sensitive hair follicles is mediated by dihydrotestosterone (DHT), which is formed in these tissues by 5 alpha-reduction of testosterone. A possible mechanism for increased body hair in some human populations might, therefore, be an increase in 5 alpha-reductase activity, resulting in elevated tissue levels of DHT. If present, this finding could have other important clinical implications, since the 5 alpha-reductase enzyme is pivotal in the pathophysiology of prostatic disease. To explore differences in clinical and biochemical parameters of androgen action, we conducted a study of 184 caucasian and Chinese subjects in whom we evaluated chest hair density and serum levels of androgen precursors and 5 alpha-reduced androgen metabolites. Differences in chest hair density were most notable in the men, in whom comparative mean chest hair scores (using a scale of 0-4) were 3.0 vs. 0.8 (P less than 0.0001), caucasian vs. Chinese. Levels of 5 alpha-reduced androgen products were also strikingly higher in the caucasian vs. Chinese subjects. Serum 3 alpha-androstanediol glucuronide levels (nanomoles per L) were 34.7 +/- 2.4 vs. 19.7 +/- 0.9 (P less than 0.001) for the men and 21.5 +/- 3.2 vs. 9.4 +/- 0.6 (P less than 0.001) for the women, and serum levels of androsterone glucuronide (nanomoles per L) were 179 +/- 26 vs. 107 +/- 7 (P less than 0.01) for the caucasian vs. Chinese men and 173 +/- 23 vs. 81 +/- 9 (P less than 0.001) for the women. Serum levels of total and bioavailable testosterone did not differ between the racial groups, but serum levels of the precursor androgens, dehydroepiandrosterone sulfate and androstenedione, were significantly higher in the caucasian vs. Chinese men, but not in the women. We conclude that increased serum levels of 5 alpha-reduced androgen metabolites in caucasians vs. Chinese subjects provide circumstantial evidence for a racial difference in 5 alpha-reductase activity and suggest a mechanism for the increased body hair observed in the caucasian men. Increased levels of precursor androgens may also play a role.
Publication
Journal: Rejuvenation Research
June/1/2010
Abstract
BACKGROUND
Poor muscle strength is a major public health concern in older persons, predisposing to functional limitations, increased fall risk, and higher mortality. Understanding risk factors for muscle strength decline may offer opportunities for prevention and treatment. One of the possible causes of muscle strength decline is imbalance between catabolic and anabolic signaling. This study aims to examine whether high levels of multiple catabolic and low levels of multiple anabolic biomarkers predict accelerated decline of muscle strength.
METHODS
In a representative sample of 716 men and women aged>>or=65 years in the InCHIANTI study we measured C-reactive protein, interleukin-6 (IL-6), IL-1 receptor antagonist (IL-1RA), tumor necrosis factor-alpha receptor 1 as well as dehydroepiandrosterone sulfate (DHEA-S), insulin-like growth factor-1, and bioavailable testosterone. Biomarker values were divided into tertiles and the numbers of catabolic/anabolic biomarkers in the highest/lowest tertile were calculated. Hand-grip strength was measured at baseline and 3- and 6-year follow up.
RESULTS
In adjusted linear mixed models, higher concentration of IL-6 (p = 0.02) and IL-1RA (p = 0.04) as well as lower levels of DHEA-S (p = 0.01) predicted muscle strength decline. After combining all inflammatory markers, the rate of decline in grip strength was progressively greater with the increasing number of dysregulated catabolic biomarkers (p = 0.01). No effect on accelerated muscle strength decline was seen according to number of dysregulated anabolic hormones.
CONCLUSIONS
Having multiple elevated catabolic biomarkers is a better predictor of muscle strength decline than a single biomarker alone, suggesting that a catabolic dysregulation is at the core of the mechanism leading to muscle strength decline with aging.
Publication
Journal: Steroids
January/11/2005
Abstract
Dehydroepiandrosterone (DHEA) improves vascular function, but the mechanism of this effect is unclear. Since nitric oxide (NO) regulates vascular function, we hypothesized that DHEA affects the vasculature by increasing endothelial NO production. Physiological concentrations of DHEA stimulated NO release from intact bovine aortic endothelial cells (BAEC) within 5min. This effect was mediated by activation of endothelial nitric oxide synthase (eNOS) in BAEC and human umbilical vein endothelial cells (HUVEC). Dehydroepiandrosterone increased cyclic GMP (cGMP) levels in BAEC, consistent with its effect on NO production. Albumin-conjugated DHEA also stimulated NO release, suggesting that DHEA stimulates eNOS by a plasma membrane-initiated signal. Tamoxifen blocked estrogen-stimulated NO release from BAEC, but did not inhibit the DHEA effect. Pertussis toxin abolished the acute effect of DHEA on NO release. Dehydroepiandrosterone had no effect on intracellular calcium fluxes. However, inhibition of tyrosine kinases or the mitogen-activated protein (MAP) kinase kinase (MEK) blocked NO release and cGMP production in response to DHEA. These findings demonstrate that physiological concentrations of DHEA acutely increase NO release from intact vascular endothelial cells, by a plasma membrane-initiated mechanism. This action of DHEA is mediated by a steroid-specific, G-protein coupled receptor, which activates eNOS in both bovine and human cells. The release of NO is independent of intracellular calcium mobilization, but depends on tyrosine- and MAP kinases. This cellular mechanism may underlie some of the cardiovascular protective effects proposed for DHEA.
Publication
Journal: Journal of Endocrinology
February/23/2012
Abstract
Estrogens and androgens are instrumental in the maturation of many hormone-dependent cancers. Consequently, the enzymes involved in their synthesis are cancer therapy targets. One such enzyme, steroid sulfatase (STS), hydrolyses estrone sulfate, and dehydroepiandrosterone sulfate to estrone and dehydroepiandrosterone respectively. These are the precursors to the formation of biologically active estradiol and androstenediol. This review focuses on three aspects of STS inhibitors: 1) chemical development, 2) biological activity, and 3) clinical trials. The aim is to discuss the importance of estrogens and androgens in many cancers, the developmental history of STS inhibitor synthesis, the potency of these compounds in vitro and in vivo and where we currently stand in regards to clinical trials for these drugs. STS inhibitors are likely to play an important future role in the treatment of hormone-dependent cancers. Novel in vivo models have been developed that allow pre-clinical testing of inhibitors and the identification of lead clinical candidates. Phase I/II clinical trials in postmenopausal women with breast cancer have been completed and other trials in patients with hormone-dependent prostate and endometrial cancer are currently active. Potent STS inhibitors should become therapeutically valuable in hormone-dependent cancers and other non-oncological conditions.
Publication
Journal: Inflammation Research
March/15/2009
Abstract
"Inflamm-aging" denotes the up-regulation of certain pro-inflammatory cytokines at older ages, and associated chronic diseases. It is well known that blood levels of cortisol also increase with age, an increase commonly considered to be due to activation of the Hypothalamus- Pituitary- Adrenal (HPA) axis by many non-specific stressors. On the contrary, herein I describe how the activation of Hypothalamus- Pituitary-Adrenal (HPA), far from being unspecific, constitutes: a) the main specific response and counterbalance to "Inflammaging" ('anti-inflammaging'), b) an explanation for the well known paradox of immune-senescence: i.e. the coexistence of inflammation and immunodeficiency, as well as c) a complex mechanism of remodelling elicited by inflammaging, explaining the long and winding pathophysiological road that goes from robustness to frailty. Indeed, the phenomenon of anti-inflammaging, mainly exerted by cortisol, with the passage of time becomes the cause of a marked decline of immunological functions, and its coexistence with the increased levels of pro-inflammatory cytokines of inflammaging, ultimately have negative impacts on metabolism, bone density, strength, exercise tolerance, the vascular system, cognitive function, and mood. Thus inflammaging and anti-inflammaging together determine many of the progressive pathophysiological changes that characterize the "aged-phenotype", and the struggle to maintain robustness finally results in frailty.The same consequences also result the age-dependent decline of dehydroepiandrosterone (DHEA).
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
September/17/2006
Abstract
OBJECTIVE
Girls with precocious pubarche (PP, pubic hair at < 8 yr of age) are at high risk for early onset and rapid progression of puberty, in particular if their prenatal growth was restrained, i.e. low birth weight (LBW), and followed by rapid postnatal catch-up of weight gain. We postulated that insulin resistance contributes to early onset and rapid progression of puberty in LBW-PP girls and thus explored the puberty-delaying effects of insulin sensitization with metformin initiated shortly after PP diagnosis.
METHODS
The study population consisted of 38 prepubertal LBW girls with PP attributed to exaggerated adrenarche [mean body weight, 2.4 kg; age, 7.9 yr; body mass index (BMI), 18.4 kg/m(2)]. These girls were randomly assigned to remain untreated (n = 19) or to receive metformin (n = 19; 425 mg/d) for 2 yr.
METHODS
Pubertal staging, age at menarche, body composition by absorptiometry, fasting insulin, glucose, lipids, leptin, IGF-I, IGF-binding protein-1, testosterone, dehydroepiandrosterone sulfate, and SHBG were the main outcome measures.
RESULTS
Metformin treatment was associated with a less adipose body composition (and lower serum leptin levels) and with a 0.4-yr delay in the clinical onset of puberty (Tanner B2; 9.5 vs. 9.1 yr; P < 0.01). These findings were corroborated by a delay of at least 1 yr in the puberty-associated rise of circulating IGF-I (P < 0.01). Available results also point to a metformin-associated delay of menarche (P < 0.02). Gain in height and lean mass was not divergent between study subgroups.
CONCLUSIONS
The efficacy of early metformin treatment in PP girls is here extended to include not only a less adipose body composition after 2 yr but also a less advanced onset of puberty, whereas height gain is maintained. These findings open the perspective that, ultimately, metformin treatment may also prove to heighten the short adult stature of LBW-PP girls.
Publication
Journal: Endocrinology
February/22/1999
Abstract
Dehydroepiandrosterone (DHEA) is abundantly found in brain tissues of several species, including human. However, the cellular origin and pathway by which DHEA is synthesized in brain are not yet known. We have, therefore, initiated pilot experiments to explore gene expression of cytochrome P450 17alpha-hydroxylase (P450c17), the key steroidogenic enzyme for androgen synthesis, and evaluate DHEA production by highly purified astrocytes, oligodendrocytes, and neurons. Using RT-PCR, we have demonstrated for the first time that astrocytes and neurons in the cerebral cortex of neonatal rat brain express P450c17. The presence of P450c17 in astrocytes and neurons was supported by the ability of these cells to metabolize pregnenolone to DHEA in a dose-dependent manner as determined by RIA. These data were further confirmed by production of androstenedione by astrocytes using progesterone as a substrate. However, cortical neurons express a low transcript of P450c17 messenger RNA and produce low levels of DHEA and androstenedione compared with astrocytes. Oligodendrocytes neither express the messenger RNA nor produce DHEA. The production of DHEA by astrocytes is not limited to cerebral cortex, as hypothalamic astrocytes produce DHEA at a level 3 times higher than that produced by cortical astrocytes. Cortical and hypothalamic astrocytes also have the capacity to metabolize DHEA to testosterone and estradiol in a dose-dependent manner. However, hypothalamic astrocytes were 3 times more active than cortical astrocytes in the metabolism of DHEA to estradiol. In conclusion, our data presented evidence that astrocytes and neurons express P450c17 and synthesize DHEA from pregnenolone. Astrocytes also have the capacity to metabolize DHEA into sex steroid hormones. These data suggest that as in gonads and adrenal, DHEA is biosynthesized in the brain by a P450c17-dependent mechanism.
Publication
Journal: Bone
June/15/1988
Abstract
This study was undertaken to evaluate the effect of obesity on the postmenopausal bone mass. Bone mineral density, measured by dual photon absorptiometry of the lumbar spine, serum osteocalcin (OC), fasting urinary calcium to creatinine (Ca:Cr), serum estradiol (E2) dehydroepiandrosterone (DHA) and testosterone (T) were measured in 176 women aged 45-71 years. Women were divided into four groups according to their menopausal status and their weight: 49 perimenopausal, 28 obese perimenopausal, 49 obese postmenopausal. Within each population (perimenopausal and postmenopausal), mean age was the same, only weight was significantly different (p less than 0.0001). For the two groups of postmenopausal women mean interval since menopause (YSM) was the same (5.8 +/- 3 and 5.4 +/- 5 yr). Comparison between groups revealed a significant effect of menopausal status and obesity on BMD and bone turnover. As compared to perimenopausal women, BMD was lower, OC and Ca: Cr higher only in nonobese-postmenopausal women. E2, T, DHA did not differ between the two groups of postmenopausal women. The results of this study suggest that even moderate obesity can play a protective role on postmenopausal bone loss.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
April/29/2013
Abstract
BACKGROUND
A broad analysis of adrenal gland-derived 19-carbon (C19) steroids has not been reported. This is the first study that uses liquid chromatography-tandem mass spectrometry to quantify 9 C19 steroids (androgens and their precursors), estrone, and estradiol in the adrenal vein (AV) of women, before and after ACTH stimulation.
OBJECTIVE
The objective of this study was to define the adrenal androgen metabolome in women before and after ACTH infusion.
METHODS
This was a retrospective study.
METHODS
Seven women, aged 50.4 ± 5.4 years, with suspected diagnosis of an adrenal aldosterone-producing adenoma were included in the study.
METHODS
AV and iliac serum samples were collected before and after administration of ACTH (15 minutes). AV samples were analyzed using for concentrations of 9 unconjugated C19 steroids, estrone, and estradiol. Dehydroepiandrosterone sulfate (DHEA-S) was quantified by radioimmunoassay.
RESULTS
AV levels of DHEA-S were the highest among the steroids measured. The most abundant unconjugated C19 steroids in AV were 11β-hydroxyandrostenedione (11OHA), dehydroepiandrosterone (DHEA), and androstenedione (A4). ACTH significantly increased the adrenal output of 9 of the 12 steroids that were measured. ACTH increased the mean AV concentration of DHEA-S by 5-fold, DHEA by 21-fold, A4 by 7-fold, and 11OHA by 5-fold. 11β-Hydroxytestosterone and testosterone were found to be potent androgen receptor agonists when tested with an androgen-responsive cell reporter model.
CONCLUSIONS
The current study indicates that the adrenal gland secretes primarily 3 weak androgens, namely DHEA, 11OHA, and A4. Active androgens, including testosterone and 11β-hydroxytestosterone, are also produced but to a lesser degree.
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