Effect of dehydroepiandrosterone on neurotransmitter levels and appetite regulation of the obese Zucker rat. The Obesity Research Program

Neuroactive Steroids and Sex-Dimorphic Nervous Damage Induced by Diabetes Mellitus

Diabetes mellitus is a metabolic disease where improper glycaemic control may induce severe complications in different organs. In this review, we will discuss alterations occurring in peripheral and central nervous system of patients with type 1 (i.e., insulin dependent diabetes mellitus,) or type 2 diabetes (i.e., non-insulin dependent diabetes mellitus), as well as related experimental models. A particular focus will be on the role exerted by neuroactive steroids (i.e., important regulators of nervous functions) in the nervous damage induced by diabetes. Indeed, the nervous levels of these molecules are affected by the pathology and, in agreement, their neuroprotective effects have been reported. Interestingly, the sex is another important variable. As discussed, nervous diabetic complications show sex dimorphic features in term of incidence, functional outcomes and neuroactive steroid levels. Therefore, these features represent an interesting background for possible sex-oriented therapies with neuroactive steroids aimed to counteract nervous damage observed in diabetic pathology.

Basal blood DHEA-S/cortisol levels predicts EMDR treatment response in adolescents with PTSD

OBJECTIVE

In literature, recent evidence has shown that the hypothalamic-pituitary-adrenal (HPA) axis can be dysregulated in patients with post-traumatic stress disorder (PTSD) and HPA axis hormones may predict the psychotherapy treatment response in patients with PTSD. In this study, it was aimed to investigate changing cortisol and DHEA-S levels post-eye movement desensitization and reprocessing (EMDR) therapy and the relationship between treatment response and basal cortisol, and DHEA-S levels before treatment.

METHOD

The study group comprised 40 adolescents (age, 12-18 years) with PTSD. The PTSD symptoms were assessed using the Child Depression Inventory (CDI) and Child Post-traumatic Stress Reaction Index (CPSRI) and the blood cortisol and DHEA-S were measured with the chemiluminescence method before and after treatment. A maximum of six sessions of EMDR therapy were conducted by an EMDR level-1 trained child psychiatry resident. Treatment response was measured by the pre- to post-treatment decrease in self-reported and clinical PTSD severity.

RESULTS

Pre- and post-treatment DHEA-S and cortisol levels did not show any statistically significant difference. Pre-treatment CDI scores were negatively correlated with pre-treatment DHEA-S levels (r: -0.39). ROC analysis demonstrated that the DHEA-S/cortisol ratio predicts treatment response at a medium level (AUC: 0.703, p: .030, sensitivity: 0.65, specificity: 0.86).

CONCLUSION

The results of this study suggested that the DHEA-S/cortisol ratio may predict treatment response in adolescents with PTSD receiving EMDR therapy. The biochemical parameter of HPA-axis activity appears to be an important predictor of positive clinical response in adolescent PTSD patients, and could be used in clinical practice to predict PTSD treatment in the future.

Neuroactive steroids and diabetic complications in the nervous system

Important complications of diabetes mellitus in the nervous system are represented by diabetic peripheral neuropathy and diabetic encephalopathy. In this context, an important link is represented by neuroactive steroids (i.e., steroids coming from peripheral glands and affecting nervous functionality as well as directly synthesized in the nervous system). Indeed, diabetes does not only affect the reproductive axis and consequently the levels of sex steroid hormones, but also those of neuroactive steroids. Indeed, as will be here summarized, the levels of these neuromodulators present in the central and peripheral nervous system are affected by the pathology in a sex-dimorphic way. In addition, some of these neuroactive steroids, such as the metabolites of progesterone or testosterone, as well as pharmacological tools able to increase their levels have been demonstrated, in experimental models, to be promising protective agents against diabetic peripheral neuropathy and diabetic encephalopathy.

Cortisol and DHEA in development and psychopathology

Dehydroepiandrosterone (DHEA) and cortisol are the most abundant hormones of the human fetal and adult adrenals released as end products of a tightly coordinated endocrine response to stress. Together, they mediate short- and long-term stress responses and enable physiological and behavioral adjustments necessary for maintaining homeostasis. Detrimental effects of chronic or repeated elevations in cortisol on behavioral and emotional health are well documented. Evidence for actions of DHEA that offset or oppose those of cortisol has stimulated interest in examining their levels as a ratio, as an alternate index of adrenocortical activity and the net effects of cortisol. Such research necessitates a thorough understanding of the co-actions of these hormones on physiological functioning and in association with developmental outcomes. This review addresses the state of the science in understanding the role of DHEA, cortisol, and their ratio in typical development and developmental psychopathology. A rationale for studying DHEA and cortisol in concert is supported by physiological data on the coordinated synthesis and release of these hormones in the adrenal and by their opposing physiological actions. We then present evidence that researching cortisol and DHEA necessitates a developmental perspective. Age-related changes in DHEA and cortisol are described from the perinatal period through adolescence, along with observed associations of these hormones with developmental psychopathology. Along the way, we identify several major knowledge gaps in the role of DHEA in modulating cortisol in typical development and developmental psychopathology with implications for future research.

Effect of dehydroepiandrosterone (DHEA) on Akt and protein kinase C zeta (PKCζ) phosphorylation in different tissues of C57BL6, insulin receptor substrate (IRS)1(-/-), and IRS2(-/-) male mice fed a high-fat diet

We have previously reported that dehydroepiandrosterone (DHEA) suppresses the activity and mRNA expression of the hepatic gluconeogenic enzyme glucose-6-phosphatase (G6Pase), and hepatic glucose production in db/db mice. Tyrosine phosphorylation levels of Insulin receptor substrate (IRS)1 and IRS2 reportedly differ between the liver and muscle tissue and the effect of DHEA on insulin signaling has not been elucidated. Therefore, we examined DHEA's effect on the liver and muscle tissue of IRS1(-/-) and IRS2(-/-) mice. Eight-week-old male C57BL6, IRS1(-/-), and IRS2(-/-) mice were fed a high-fat diet (HFD), or an HFD containing 0.2% DHEA for 4 weeks. In a separate experiment, 8-week-old male C57BL6 mice were fed an HFD or an HFD containing 0.2% androstenedione for 4 weeks. In an insulin tolerance test, DHEA administration decreased the initial plasma glucose levels in the C57BL6, IRS1(-/-), and IRS2(-/-) mice but did not decrease the ratios to the basal blood glucose level. Although DHEA administration increased Akt phosphorylation in the liver of the C57BL6, IRS1(-/-), and IRS2(-/-) mice, androstenedione administration did not increase Akt phosphorylation in the liver of C57BL6 mice. DHEA administration did not increase Akt and PKCζ phosphorylation in the muscle tissue of C57BL6, IRS1(-/-), or IRS2(-/-) mice. However, androstenedione administration increased Akt and PKCζ phosphorylation in the muscle tissue of C57BL6 mice. These findings suggest that the effect of DHEA on insulin action in the liver is self-mediated by DHEA or DHEA sulfate (DHEA-S) in the presence of IRS1, IRS2, or both.

Serum dehydroepiandrosterone sulfate and incident depression in the elderly: the Pro.V.A. study

OBJECTIVE

Dehydroepiandrosterone sulfate (DHEAS) appears to have a protective effect against depression, but contrasting findings are available. Therefore, we investigated whether high serum DHEAS levels were associated with any protective effect on incident depression and incident severe depression in a representative group of elderly men and women.

METHODS

In a population-based cohort longitudinal study in the general community, 789 older participants without depression and cognitive impairment at the baseline were included, among 3,099 screened subjects. Serum DHEAS levels were determined based on blood samples; incident depression and severe depression were diagnosed by means of the Geriatric Depression Scale (GDS) and confirmed by geriatricians skilled in psychogeriatric medicine.

RESULTS

No baseline differences were found in GDS across age- and gender-specific tertiles of serum DHEAS. Over 4.4 years of follow-up, 137 new cases of depression were recorded. Of them, 35 among men and 64 in women were cases of incident severe depression. Cox's regression analysis, adjusted for potential confounders, revealed that higher DHEAS levels were associated with reduced risk of incident depression irrespective of gender (HR: 0.30; 95% CI: 0.09-0.96; Wald χ(2) = 4.09; df = 1; p = 0.04; women: HR: 0.31; 95% CI: 0.14-0.69; Wald χ(2) = 8.37; df = 1; p = 0.004) and of severe incident depression only in men (HR: 0.25; 95% CI: 0.06-0.99; Wald χ(2) = 4.05; df = 1; p = 0.04).

CONCLUSION

Higher serum DHEAS levels were found to be significantly protective for the onset of depression irrespective of gender, whereas only in men was this association found also for incident severe depression.

DHEA and cognitive function in the elderly

The adrenal prohormone dehydroepiandrosterone (DHEA) and its sulphate conjugate (DHEAS) steadily decrease with age by 10% per decade reaching a nadir after the age of 80. Both DHEA and DHEAS (DHEA/S) exert many biological activities in different tissues and organs. In particular, DHEA and DHEAS are produced de novo in the brain, hence their classification as neurosteroids. In humans, the brain-to-plasma ratios for DHEA and DHEAS are 4-6.5 and 8.5, respectively, indicating a specific neuroendocrine role for these hormones. DHEA/S stimulates neurite growth, neurogenesis and neuronal survival, apoptosis, catecholamine synthesis and secretion. Together with antioxidant, anti-inflammatory and anti-glucocorticoid properties, it has been hypothesized a neuroprotective effect for DHEA/S. We conducted an accurate research of the literature using PubMed. In the period of time between 1994 and 2013, we selected the observational human studies testing the relationship between DHEA/S and cognitive function in both sexes. The studies are presented according to the cross-sectional and longitudinal design and to the positive or neutral effects on different domains of cognitive function. We also analysed the Clinical Trials, available in the literature, having cognitive domains as the main or secondary outcome. Although the cross-sectional evidence of a positive association between DHEA/S and cognitive function, longitudinal studies and RCTs using DHEA oral treatment (50mg/day) in normal or demented adult-older subjects, have produced conflicting and inconsistent results. In summary, the current data do not provide clear evidence for the usefulness of DHEA treatment to improve cognitive function in adult-older subjects. This article is part of a Special Issue entitled 'Essential role of DHEA'.

Regulation of local steroidogenesis in the brain and in prostate cancer: lessons learned from interdisciplinary collaboration

Sex steroids play critical roles in the regulation of the brain and many other organs. Traditionally, researchers have focused on sex steroid signaling that involves travel from the gonads via the circulation to intracellular receptors in target tissues. This classic concept has been challenged, however, by the growing number of cases in which steroids are synthesized locally and act locally within diverse tissues. For example, the brain and prostate carcinoma were previously considered targets of gonadal sex steroids, but under certain circumstances, these tissues can upregulate their steroidogenic potential, particularly when circulating sex steroid concentrations are low. We review some of the similarities and differences between local sex steroid synthesis in the brain and prostate cancer. We also share five lessons that we have learned during the course of our interdisciplinary collaboration, which brought together neuroendocrinologists and cancer biologists. These lessons have important implications for future research in both fields.

Dehydroepiandrosterone (DHEA) blocks the increase in food intake caused by neuropeptide Y (NPY) in the Zucker rat

Recent studies have demonstrated that neuropeptide Y (NPY) reduced the neural production of dehydroepiandrosterone (DHEA) in frog hypothalamic explants. The objective of this study was to assess if DHEA can block the NPY induced increase in food intake in lean and obese Zucker rats. Rats were given one of the following four treatments: sterile water/dimethylsulfoxide (DMSO), NPY/DMSO, water/DHEA, and NPY/DHEA. Immediately after administration of their respective treatment, rats were exposed to macronutrients for 4 h and food intake was monitored. NPY caused a significant increase in total calories consumed compared to control. Co-administration of DHEA along with NPY blocked this NPY dependent effect. These results suggest that DHEA blocks the over-eating in satiated rats induced by NPY. Measurement of changes in regional hypothalamic and raphe monoamine neurotransmitters known to affect food intake suggested a possible role of serotonin fluctuations in the ventromedial hypothalamus (VMH) guiding this behaviour.

Monoamines, BDNF, Dehydroepiandrosterone, DHEA-Sulfate, and Childhood Depression-An Animal Model Study

Basal levels of monoamines and DHEA in four main limbic brain regions were measured in prepubertal Wistar Kyoto (WKY) rats (a putative animal model of childhood depression). Basal levels of “Brain-Derived Neurotrophic Factor (BDNF)” were also determined in two regions in the hippocampus, compared with Wistar strain controls. In the second phase, we examined the responsiveness of prepubertal WKY rats to different types of chronic antidepressant treatments: Fluoxetine, Desipramine, and dehydroepiandrosterone sulfate (DHEAS). WKY prepubertal rats exhibited different monoamine levels in the limbic system, reduced DHEA levels in the VTA and lower levels of BDNF in the hippocampus CA3 region compared to controls. In prepubertal WKY rats, only treatment with DHEAS produced a statistically significant decrease in immobility, compared to saline-administered controls in the forced swim test. Wistar controls were not affected by any antidepressant. The results imply that DHEA(S) and BDNF may be involved in the pathophysiology and pharmacotherapy of childhood depression.

Effects of dehydroepiandrosterone supplement on health-related quality of life in glucocorticoid treated female patients with systemic lupus erythematosus

The objective of this study was to evaluate the efficacy of low dose dehydroepiandrosterone (DHEA) on health-related quality of life (HRQOL) in glucocorticoid treated female patients with systemic lupus erythematosus (SLE). Forty one women ( >or= 5 mg prednisolone/day) were included in a double-blind, randomized, placebo-controlled study for 6 months where DHEA was given at 30 mg/20 mg ( <or= 45/ >or= 46 years) daily, or placebo, followed by 6 months open DHEA treatment to all patients. HRQOL was assessed at baseline, 6 and 12 months, using four validated questionnaires and the patients' partners completed a questionnaire assessing mood and behaviour at 6 months. DHEA treatment increased serum levels of sulphated DHEA from subnormal to normal. The DHEA group improved in SF-36 "role emotional" and HSCL-56 total score (both p<0.05). During open DHEA treatment, the former placebo group improved in SF-36 "mental health" (p<0.05) with a tendency for improvement in HSCL-56 total score (p=0.10). Both groups improved in McCoy's Sex Scale during active treatment (p<0.05). DHEA replacement decreased high-density lipoprotein (HDL) cholesterol and increased insulin-like growth factor I (IGF-I) and haematocrit. There were no effects on bone density or disease activity and no serious adverse events. Side effects were mild. We conclude that low dose DHEA treatment improves HRQOL with regard to mental well-being and sexuality and can be offered to women with SLE where mental distress and/or impaired sexuality constitutes a problem.

Dehydroepiandrosterone and monoamines in the limbic system of a genetic animal model of childhood depression

Monoamines and dehydroepiandrosterone (DHEA) levels were measured in a genetic animal model for childhood depression in four subcortical structures: nucleus accumbens (Nac), ventral tegmental area (VTA), amygdala and hypothalamus. The "depressive-like" strain was the Flinders Sensitive Line (FSL), compared to their controls, Sprague-Dawley (SD) rats. Prepubertal FSL rats showed abnormal levels of only a few monoamines and their metabolites in these brain regions. This is in contrast to former studies, in which adult FSL rats exhibited significantly higher levels of all the monoamines and their metabolites measured. These different abnormal monoamine patterns between the "depressed" prepubertal rats and their adults, may help to explain why depressed children and adolescents fail to respond to antidepressant treatment as well as adults do. On the other hand, FSL prepubertal rats exhibited the same pattern of abnormal DHEA basal levels as was found in adults in previous experiments. The results from the current study may imply that treatment with DHEA could be a promising novel therapeutic option for depressed children and adolescents that fail to respond to common (monoaminergic) antidepressant treatments.

Effect of dehydroepiandrosterone on protein and fat digestibility, body protein and muscular composition in high-fat-diet-fed old rats

The main objective of the present study was to examine the effects of dehydroepiandrosterone (DHEA) on the digestive efficiency of dietary protein and fat. Second, we analysed the specific changes in muscle composition induced by the hormone. DHEA was given in the diet (0·5 %, w/w) to 75-week-old, high-fat-fed Sprague–Dawley rats (n11) for 13 weeks; age- and weight-matched rats fed on the same diet without DHEA supplementation were used as controls (n10). To determine dietary protein and fat apparent digestibility coefficients, 1-week 24 h faecal depositions were collected. In parallel, urine N was assessed. These assays were performed twice, in the short term (2-week treatment) and in the long term (13-week treatment). Body and gastrocnemius muscle compositions were also analysed. The present results show that DHEA decreased energy intake, body weight, body fat, adipocyte size and number (P < 0·001). The feed efficiency ratio indicates that DHEA-treated rats were less efficient in transforming nutrients fed into their own biomass. Also, a short-term reduction in protein digestibility (P < 0·05) and in body-protein degradation (P < 0·01) was found in DHEA-treated rats, resulting in an increased content of body protein (P < 0·05). Gastrocnemius muscles were smaller, as a result of fat (P < 0·05) but not protein reduction. In conclusion, we confirm the slimming effect of DHEA and, for the first time, we demonstrate that DHEA has an effect at the digestive level. The anti-obesity properties of DHEA could be related to a reduction in protein digestibility in the short term and a protective effect on body protein with a selective mass loss from body fat.

The influence of dehydroepiandrosterone and 8-OH-DPAT on the caloric intake and hypothalamic neurotransmitters of lean and obese Zucker rats

The 5 HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)-tetraline (8-OH-DPAT) increases the food intake of satiated Zucker rats, both lean and obese. Associated with this increased intake are changes in the hypothalamic content of serotonin and its metabolite, 5-HIAA (5-hydroxyindole-3-acetic acid); serotonin is increased while the level of 5-HIAA is decreased. Analysis of individual 5-HIAA/5-hydroxytryptamine (5-HT) ratios, a measure of serotonin turnover indicate that 8-OH DPAT affected serotonin turnover equally and dramatically in both phenotypes. This would be an expected physiological action of an autofeedback mechanism by a 5-HT1A receptor agonist. Dehydroepiandrosterone (DHEA) at doses as low as 10 mg/kg blocks the 8-OH-DPAT-induced increase in food intake but does not alter food intake of control satiated Zucker rats. The mechanism of DHEA's action was investigated by monitoring the steroid's effect on hypothalamic neurotransmitters in this satiated model. DHEA by itself induced some change in 5-HIAA in the obese satiated model but not the lean. 8-OH-DPAT, by itself, dramatically decreased serotonin turnover in either lean or obese rats, and DHEA combined with 8-OH-DPAT did not further change serotonin turnover, suggesting DHEA may work through mechanisms other than monoamines to cause its inhibition of 8-OH-DPAT-induced behavioral effects at such low doses.

Caloric intake and hypothalamic neurotransmitters in Zucker rats made acutely diabetic with streptozocin

Zucker rats, lean and obese, treated with low dose intraperitoneal injections of streptozocin become hyperglycemic within 24h. Insulin levels fall, although the obese animal remains hyperinsulinemic. Associated with these changes in glucose and insulin there are transient decreases in caloric intake. Macronutrient selection studies show that protein consumption decreases. There is a trend for fat intake to decrease. The levels of hypothalamic neurotransmitters in the lean animals are not altered by streptozocin. The levels of 5-hydroxyindoleacetic acid increases in the streptozocin-treated obese animal in the paraventricular region, ventromedial region and the raphe. Serotonin is also significantly increased in the paraventricular region of the obese rat. These results suggest that acutely, treatment with streptozocin injures pancreatic islets, causing, in turn, decreases in insulin levels so that hyperglycemia ensues in both phenotypes. Associated with these perturbations are decreases in caloric intake. The magnitude of change in insulin levels is much greater in the obese rat. It is hypothesized that in the obese Zucker rat decrements in food intake are mediated by increase in serotonin turnover in the hypothalamus and these changes are related to changes of insulin levels. These data support the concept that circulating insulin affects hypothalamic neurotransmitters.

The Use of Dehydroepiandrosterone Therapy in Clinical Practice

Dehydroepiandrosterone (DHEA) therapy is controversial due to sensationalized reports of epidemiologic studies and the over-the-counter availability of DHEA. Human clinical trials have investigated the potential efficacy of DHEA therapy in multiple conditions with resultant inconsistencies in findings. DHEA is unique compared with other adrenal steroids because of the fluctuation in serum levels found from birth into advancing age. The lower endogenous levels of DHEA and DHEA sulfate found in advancing age have been correlated with a myriad of health conditions. Also, some studies suggest gender-specific actions of endogenous and exogenous DHEA. We reviewed only pharmacokinetic studies and human clinical trials investigating the efficacy of DHEA therapy that were placebo-controlled as these provided the most reliable scientific basis for the evaluation of DHEA therapy. Pharmacodynamic studies suggest that doses of 30-50mg of oral DHEA may produce physiologic androgen levels, especially in women. These studies report a dose-dependent effect and lack of accumulation of serum androgen levels. Pharmacologic studies also reveal a gender-specific response to DHEA therapy such that testosterone levels are increased in women but not in men. Clinical trials suggest that 50mg of oral DHEA, but not <30mg, can increase serum androgen levels to within the physiologic range for young adults with primary and secondary adrenal insufficiency, possibly improve sexual function, improve mood and self-esteem, and decrease fatigue/exhaustion. Whereas DHEA replacement therapy may be effective in treating patients with adrenal insufficiency, human clinical trials investigating its efficacy in conditions such as systemic lupus erythematosus, HIV, Alzheimer disease, advancing age, male sexual dysfunction, perimenopausal symptoms, depression, and cardiovascular disease have not provided consistent findings.

Urinary steroids in young women with eating disorders

Urinary steroid components were measured after enzyme hydrolysis and methoxym-silyl derivatization by capillary gas chromatography in young women with eating disorders. Using three internal standards, programmed temperature from 50 to 300 degrees C and flame ionization detection, on ULTRA-1 capillary column the separation of 28 steroid components is possible. Fifteen young women with different eating disorders, i.e. anorexia nervosa, bulimia nervosa and bulimarexia (aged 16-28 years) and 15 healthy women (aged 22-26 years) collected 24-h urine. A significant decrease of dehydroepiandrosterone (p<0.05) and a significant elevation of the stress marker allo-tetrahydrocorticosterone (p<0.05) were observed in the patients with compared to the controls. Among the patients two groups were defined due to a significant difference in the content of the cortisol metabolites compared to each other and to controls (p<0.01). The results confirm the role of dehydroepiandrosterone in eating disorders. The increased level of the stress marker allo-tetrahydrocorticosterone refers to the involvement of stress in these diseases, but the relevance of hormone alteration to the pathophysiology of eating disorders remains to be elucidated. The reason of the differences in cortisol metabolites levels in some patients needs further investigations.

Dietary dehydroepiandrosterone inhibits bone marrow and leukemia cell transplants: role of food restriction

Dietary dehydroepiandrosterone (DHEA) inhibits the proliferation of syngeneic bone marrow cells (BMC) infused into lethally irradiated mice. Potential mechanisms for suppression of hematopoiesis were evaluated and the findings were as follows: (i) depletion of NK, T, B or macrophage cells failed to reverse suppression by DHEA; (ii) stem cell stimulation by erythropoietin, growth hormone, interleukin-2, Friend leukemia virus, or cyclophosphamide failed to reverse suppression; (iii) supplementation of fatty acids, mevalonate, or deoxyribonucleotides, which are dependent upon glucose-6-phosphate dehydrogenase function, did not enhance BMC growth in mice fed DHEA; (iv) DHEA downstream metabolites 4-androstenedione and 17beta-estradiol, as well as the synthetic steroid, 16alpha-chloroepiandrosterone (but not testosterone or 5-androstene-3beta,17beta-diol), also inhibited BMC growth. Tamoxifen antagonized the effects of 17beta-estradiol but not DHEA; (v) dietary DHEA causes hypothermia, but housing of DHEA-fed mice at 34 degrees C to maintain normal body temperature did not reverse suppression; (vi) DHEA leads to a decrease in food intake in rodents. Pair-feeding control diet to mice fed DHEA mimicked the effects of dietary DHEA; (vii) adrenalectomy and orchiectomy decrease the levels of stress and sex hormones, respectively. Neither procedure affected the ability of food restriction or DHEA feeding to inhibit hematopoiesis; (viii) growth of GR-3 NM pre-B leukemia cells in unirradiated mice was also suppressed by DHEA or food restriction. We conclude that DHEA, by reducing food intake in mice, inhibits bone marrow and leukemia cell growth. The precise mechanism(s) by which reduced food intake per se inhibits hematopoiesis is not known, but may involve an increased rate of cellular apoptosis.

DHEA administration increases brown fat uncoupling protein 1 levels in obese OLETF rats

We found that UCP-1 and UCP-3 mRNA expression levels and the UCP-1 protein content in brown adipose tissue (BAT) were reduced in prediabetic OLETF rats than the lean LETO rats. Administration of dehydroepiandrosterone (DHEA) for 17 days induced remarkable weight loss, which was in part attributed to an enhanced utilization of ingested energy. DHEA administration significantly increased the levels of BAT UCP-1 and UCP-3 mRNA expression. Among the upstream signals for UCP-1 regulation, expression levels of the beta 3 adrenergic receptor (beta(3)AR) and PPAR gamma coactivator-1 (PGC-1) were significantly decreased in the OLETF rats and increased by DHEA administration. The decreased expression levels of UCP-1 and its upstream regulators, beta(3)AR and PGC-1, in BAT may contribute to inefficient energy utilization and obesity in OLETF rats, which was corrected by DHEA treatment.

Basal plasma hormone levels in depressed perimenopausal women

BACKGROUND

An association between abnormal changes in reproductive endocrine function during the perimenopause and the onset of depression in some women has been suggested but remains controversial.

METHODS

We examined basal plasma hormone levels in two samples of women with well characterized, first onset depression (major or minor) during the perimenopause and matched comparison groups of asymptomatic women. Results were compared by analysis of variance.

RESULTS

No significant diagnosis-related differences were observed in plasma hormone measures of the following: follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), estrone (E1), total (T) or free testosterone (FT), or the E2/LH ratio. We did identify significantly lower morning plasma dehydroepiandrosterone (DHEA) and its sulphated metabolite DHEA-S (but not cortisol) levels in the depressed women compared to the non-depressed comparison group. Women with hot flushes (regardless of the presence of depression) were significantly older than women without flushes, had significantly higher plasma levels of FT, LH and FSH, and had significantly lower E2/LH ratios.

CONCLUSIONS

Women with first onset depression during the perimenopause are not distinguished from controls on the basis of basal hormone measures of ovarian estrogens, testosterone, or gonadotropins. However, perimenopause-related changes in E2 may interact with low levels of DHEA in some women to increase their vulnerability to develop depression. In contrast to perimenopause-related vasomotor symptoms, depression during the perimenopause is not associated with a simple hormone deficiency state. The relatively low levels of E2 and E1 in the depressed women may have met statistical significance in a much larger and homogenous sample.

Levels of hypothalamic neurotransmitters in lean and obese Zucker rats

Hypothalamic neurotransmitter levels were compared between groups of Zucker rats. Animals were grouped by gender, phenotype and preference for dietary fat. Before sacrifice all animals consumed a standard rat chow diet and were fasted overnight. Five rats from each of eight groups were assayed. Hypothalamic regions (lateral, LH; ventromedial, VMH; paraventricular, PVN) and the raphe were isolated and analyzed for dopamine, norepinephrine, epinephrine, serotonin and 5-hydroxyindoleacetic acid. A factorial analysis of variance was used to compare the concentrations of these biogenic amines in the four regions across phenotypic, gender and fat preference profiles. No differences were demonstrated between groups based upon fat food preference. Epinephrine and 5-HIAA content varied between lean and obese animals but there were no differences in the content of serotonin, norepinephrine or dopamine. The results are consistent with the hypothesis that the obese animal eats more because it releases less of the satiety-inducing neurotransmitter serotonin in the hypothalamus.

Intranasal administration of adrenocorticotropin-(1-24) stimulates adrenocortical hormone secretion

To determine the efficiency of transmucosal absorption of ACTH, we measured serum cortisol, aldosterone, dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEA-S) levels after intranasal (in) vs. iv administration of ACTH-(1-24) (250 microg) in 12 healthy adult men (mean age, 24.3 +/- 3.2 yr; range, 21-31 yr), who had received no prior medication and had no symptoms of rhinitis. Blood was collected at 0, 30, 60, 120, and 180 min after administration of ACTH-(1-24), and the levels of adrenocortical steroids were measured by specific RIAs. There were no side-effects associated with in or iv ACTH administration. After in administration, serum cortisol and aldosterone increased rapidly by 224.7 +/- 39.2% and 147.2 +/- 50.5%, respectively, peaking 30 min after ACTH-(1-24) administration, and decreasing to basal levels within 120 min. These increases in serum cortisol and aldosterone were lower than those obtained after iv administration. Thirty minutes after in or iv administration of ACTH-(1-24), DHEA increased by 49.1 +/- 27.2% and 81.6 +/- 17.1%, respectively, and remained elevated for 180 min. Serum DHEA-S levels did not change after in administration of ACTH-(1-24) and increased only slightly after iv injection. Adrenocortical steroid levels did not increase after in administration of saline. These data demonstrate that adrenocortical steroids are stimulated by in administration of ACTH-(1-24). We suggest that intranasal administration of ACTH offers both a diagnostic approach as an adrenal function test and a therapeutic approach as ACTH replacement therapy in patients with ACTH deficiency. The latter may be more physiological than glucocorticoid replacement.

Dehydroepiandrosterone alters Zucker rat soleus and cardiac muscle lipid profiles

High levels of serum free fatty acids (FFA) and lower proportions of polyunsaturated (PU) FAs, specifically arachidonic acid (AA), are common in obesity, insulin resistance (IR), and type 2 diabetes mellitus. Dehydrepiandrosterone (DHEA) decreases body fat content, dietary fat consumption, and insulin levels in obese Zucker rats (ZR), a genetic model of human youth onset obesity and type 2 diabetes. This study was conducted to investigate DHEA's effects on lean and obese ZR serum FFA levels and total lipid (TL) FA profiles in heart and soleus muscle. We postulated that DHEA alters serum FFA levels and tissue TL FA profiles of obese ZR so that they resemble the levels and profiles of lean ZR. If so, DHEA may directly or indirectly alter tissue lipids, FFA flux, and perhaps lower IR in obese ZR. Lean and obese male ZR were divided into six groups with 10 animals in each: obese ad libitum control, obese pair-fed, obese DHEA, lean ad libitum control, lean pair-fed, and lean DHEA. All animals had ad libitum access to a diet whose calories were 50% fat, 30% carbohydrate, and 20% protein. Only the diets of the DHEA treatment groups were supplemented with 0.6% DHEA. Pair-fed groups were given the average number of calories per day consumed by their corresponding DHEA group, and ad libitum groups had 24-h access to the DHEA-free diet. Serum FFA levels and heart and soleus TL FA profiles were measured. Serum FFA levels were higher in obese (approximately 1 mmol/L) compared to lean (approximately 0.6 mmol/L) ZR, regardless of group. In hearts, monounsaturated (MU) FA were greater and PU FA were proportionally lower in obese compared to the lean rats. In soleus, saturated and MU FA were greater and PU FA were proportionally lower in the obese compared to the lean rats. DHEA groups displayed significantly increased proportions of TL AA and decreased oleic acid in both muscle types. Mechanisms by which DHEA alters TL FA profiles are a reflection of changes occurring within specific lipid fractions such as FFA, phospholipid, and triglyceride. This study provides initial insights into DHEA's lipid altering effects.

Food restriction-like effects of dietary dehydroepiandrosterone. Hypothalamic neurotransmitters and metabolites in male C57BL/6 and (C57BL/6 x DBA/2)F1 mice

Dehydroepiandrosterone (DHEA) is a precursor of sex hormones in mammals. Dietary DHEA serves to prevent or inhibit various diseases and also lengthens life spans of animals. Moreover, dietary DHEA inhibits food intake in certain strains of mice. We administered DHEA (0.45% w/w of food) to C57BL/6 (B6) and (B6 x DBA/2)F1 (BDF1) mice for 5 weeks. Food intake was inhibited in both strains of mice during the first week. Thereafter, B6, but not BDF1, mice consumed less food. Because hypothalamic serotonin and/or dopamine regulate appetite, satiety and other behaviors, the hypothesis tested was that hypothalamic concentration of serotonin, dopamine and/or their metabolites are affected differentially in B6 and BDF1 mice fed DHEA. In another study, mice were fed the AIN-76A diet with or without DHEA for 1 and 7 days or were pair-fed to DHEA-fed mice for 7 days. On Day 1 of DHEA feeding (acute effects) hypothalamic levels of serotonin, dopamine, and metabolites were unchanged in B6 mice, but levels of dopamine were increased and levels of dopamine metabolites were decreased in BDF1 mice. On Day 7 of DHEA feeding, levels of serotonin were increased in BDF1 but not B6 mice. On Day 7 of pair-feeding there were decreased levels of hypothalamic dopamine metabolites in BDF1 but not B6 mice. Paraventricular nuclei of BDF1 mice had decreased levels of serotonin but not of dopamine in all groups. Serum levels of DHEA and its metabolite, 5-androstene-3beta,17beta-diol, correlated significantly only with serotonin concentrations in BDF1 mice. The salient findings of these experiments are that DHEA inhibits food intake to a greater extent in B6 than in BDF1 mice. However, alterations of hypothalamic neurotransmitters were greater in BDF1 than in B6 mice. Because BDF1 and B6 mice share B6 genes, relevant gene(s) derived from DBA/2 mice might mediate the different responses detected.

Effects of dehydroepiandrosterone and quinapril on nephropathy in obese Zucker rats

BACKGROUND

The obese Zucker rat exhibits insulin resistance, develops nephropathy at an early age, and may be a model of diabetic nephropathy. Dehydroepiandrosterone (DHEA) may ameliorate many of the factors that contribute to diabetic nephropathy, while angiotensin-converting enzyme inhibitors are known to be effective. One marker of nephropathy is the expression of alpha-smooth muscle actin.

METHODS

We studied the effect of DHEA on the expression of alpha-smooth muscle actin in obese Zucker rats and compared the changes with those in a control group, a group given quinapril, and a group on a low-calorie diet. DHEA (0.6%) added to plain chow, quinapril (0.3 mg/kg) added to drinking water, and a low-calorie diet based on pair-feeding were administered to obese rats from age 4 to 20 weeks. Immunohistochemical expression of alpha-smooth muscle actin, a marker of interstitial and glomerular fibrosis and an early indicator of nephropathy, was measured semiquantitatively in glomeruli, cortical interstitium, and medullary interstitium on a scale of 0 to 4 and was reported as mean +/- SEM.

RESULTS

When compared with the obese control group, quinapril exhibited a marked reduction in alpha-smooth muscle actin staining in glomeruli, cortical interstitium, and medullary interstitium (P < 0.0005); DHEA reduced alpha-smooth muscle actin staining in cortical interstitium and medullary interstitium (P < 0. 005), and a low-calorie diet reduced alpha-smooth muscle actin staining in cortical and medullary interstitium (P < 0.005), which was similar to the effects of DHEA.

CONCLUSIONS

DHEA was similar to a low-calorie diet in reducing the immunohistochemical staining of alpha-smooth muscle actin in obese Zucker rats. However, quinapril exerted a marked protective effect on the development of fibrosis, as indicated by alpha-smooth muscle actin staining, which was significantly less than that of DHEA at the doses studied.

Plasma levels of neuroactive steroids are increased in untreated women with anorexia nervosa or bulimia nervosa

OBJECTIVE

Animal data suggest that neuroactive steroids, such as 3alpha,5alpha-tetrahydroprogesterone (3a,5a-THP), dehydroepiandrosterone (DHEA), and its sulfated metabolite (DHEA-S), are involved in the modulation of eating behavior, aggressiveness, mood, and anxiety. Anorexia nervosa (AN) and bulimia nervosa (BN) are eating disorders characterized by abnormal eating patterns, depressive and anxious symptoms, enhanced aggressiveness, and endocrine alterations. Previous studies reported decreased blood levels of DHEA and DHEA-S in small samples of anorexic patients, whereas no study has been performed to evaluate the secretion of these neuroactive steroids in BN as well as the production of 3alpha,5alpha-THP in both AN and BN. Therefore, we measured plasma levels of DHEA, DHEA-S, 3alpha,5alpha-THP and other hormones in patients with AN or BN and explored possible relationships between neuroactive steroids and psychopathology.

METHOD

Ninety-two women participated in the study. There were 30 drug-free AN patients, 32 drug-free BN patients, and 30 age-matched, healthy control subjects. Blood samples were collected in the morning for determination of hormone levels. Eating-related psychopathology, depressive symptoms, and aggressiveness were rated by using specific psychopathological scales.

RESULTS

Compared with healthy women, both AN and BN patients exhibited increased plasma levels of 3alpha,5alpha-THP, DHEA, DHEA-S, and cortisol but reduced concentrations of 17beta-estradiol. Plasma testosterone levels were decreased in anorexic women but not in bulimic women. Plasma levels of neuroactive steroids were not correlated with any clinical or demographic variable.

CONCLUSIONS

These findings demonstrate increased morning plasma levels of peripheral neuroactive steroids in anorexic and bulimic patients. The relevance of such hormonal alterations to the pathophysiology of eating disorders remains to be elucidated.

Basal plasma dehydroepiandrosterone sulfate level: a possible predictor for response to electroconvulsive therapy in depressed psychotic inpatients

BACKGROUND

Dehydroepiandrosterone (DHEA) and its sulfate derivative DHEAS are neuroactive steroids. In the brain, they interact with gamma-aminobutyric acid (GABA(A)) receptors, which are involved in the regulation of anxiety and mood. The relevance of circulatory neurosteroids to psychiatric disorders and biological treatment is unknown.

METHODS

Basal plasma levels of cortisol, DHEA, and DHEAS and the DHEAS-DHEA ratio were determined in 17 psychiatric inpatients before and after six electroconvulsive (ECT) therapy sessions, and all changes were statistically analyzed. For baseline values, 25 healthy individuals served as control subjects. Severity of depression and psychosis in the patients was measured with the Hamilton Depression Rating Scale (HDRS) and the Brief Psychiatric Rating Scale, respectively.

RESULTS

Both basal and post-ECT levels of cortisol, DHEA, and DHEAS were significantly higher in the patients than in the control subjects. DHEAS levels in responding patients were higher at completion of treatment than at baseline. Patients defined as ECT nonresponders (change in HDRS < 30% from before treatments) exhibited elevated basal DHEAS levels compared with ECT responders.

CONCLUSIONS

Markedly elevated basal DHEAS levels (mean + 2 SD of control value) are associated with resistance to ECT and may serve as a potential predictive marker of nonresponsiveness to ECT in depressed patients.

Increase in hepatic content of oleic acid induced by dehydroepiandrosterone in the rat

The effects of dehydroepiandrosterone (DHEA) on the acyl composition of lipids in rat liver were studied. The content of oleic acid (18:1) in hepatic lipids was increased markedly by feeding rats a diet containing 0.5% (w/w) DHEA for 14 days. Treatment of rats with DHEA caused an increase in the activity of the terminal desaturase of the stearoyl-CoA desaturation system, without changing either the activity of NADH-cytochrome b5 reductase or the microsomal content of cytochrome b5. Among the changes observed in hepatic lipids, the increase in 18:1 content in phosphatidylcholine (PtdCho) was the most prominent; an approximately 2.5-fold increase in the proportion of 18:1 was induced at position 2, but not at position 1, by DHEA. This selective elevation of 18:1 at position 2 of PtdCho seems to be produced by the concerted actions of the induced 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase and the induced stearoyl-CoA desaturase. The content of 18:1 in serum lipids was unchanged by DHEA treatment, suggesting that secretion of lipids containing 18:1 into the circulation was not affected by DHEA. These results suggest that the elevation of hepatic content of 18:1 caused by DHEA treatment is mainly due to the induction of stearoyl-CoA desaturase.

Dehydroepiandrosterone treatment of midlife dysthymia

BACKGROUND

This study evaluated the efficacy of the adrenal androgen, dehydroepiandrosterone, in the treatment of midlife-onset dysthymia.

METHODS

A double-blind, randomized crossover treatment study was performed as follows: 3 weeks on 90 mg dehydroepiandrosterone, 3 weeks on 450 mg dehydroepiandrosterone, and 6 weeks on placebo. Outcome measures consisted of the following. Cross-sectional self-ratings included the Beck Depression Inventory, and visual analogue symptom scales. Cross-sectional objective ratings included the Hamilton Depression Rating Scale, the Cornell Dysthymia Scale and a cognitive test battery. Seventeen men and women aged 45 to 63 years with midlife-onset dysthymia participated in this study. Response to dehydroepiandrosterone or placebo was defined as a 50% reduction from baseline in either the Hamilton Depression Rating Scale or the Beck Depression Inventory.

RESULTS

In 15 patients who completed the study, a robust effect of dehydroepiandrosterone on mood was observed compared with placebo. Sixty percent of the patients responded to dehydroepiandrosterone at the end of the 6-week treatment period compared with 20% on placebo. A significant response was seen after 3 weeks of treatment on 90 mg per day. The symptoms that improved most significantly were anhedonia, loss of energy, lack of motivation, emotional "numbness," sadness, inability to cope, and worry. Dehydroepiandrosterone showed no specific effects on cognitive function or sleep disturbance, although a type II error could not be ruled out.

CONCLUSIONS

This pilot study suggests that dehydroepiandrosterone is an effective treatment for midlife-onset dysthymia.

Double-blind treatment of major depression with dehydroepiandrosterone

OBJECTIVE

This study was designed to assess possible antidepressant effects of dehydroepiandrosterone (DHEA), an abundant adrenocortical hormone in humans.

METHOD

Twenty-two patients with major depression, either medication-free or on stabilized antidepressant regimens, received either DHEA (maximum dose = 90 mg/day) or placebo for 6 weeks in a double-blind manner and were rated at baseline and at the end of the 6 weeks with the Hamilton Depression Rating Scale. Patients previously stabilized with antidepressants had the study medication added to that regimen; others received DHEA or placebo alone.

RESULTS

DHEA was associated with a significantly greater decrease in Hamilton depression scale ratings than was placebo. Five of the 11 patients treated with DHEA, compared with none of the 11 given placebo, showed a 50% decrease or greater in depressive symptoms.

CONCLUSIONS

These results suggest that DHEA treatment may have significant antidepressant effects in some patients with major depression. Further, larger-scale trials are warranted.

Dehydroepiandrosterone decreases serum tumor necrosis factor-alpha and restores insulin sensitivity: independent effect from secondary weight reduction in genetically obese Zucker fatty rats

Dehydroepiandrosterone (DHEA) and its sulfate ester are the most abundant circulating adrenal steroids in humans. Administration of DHEA has been reported to have beneficial effects on obesity, hyperlipidemia, diabetes, and atherosclerosis in obese rodents, although its effects on insulin resistance have not been fully elucidated. In this study, the effects of DHEA treatment on insulin sensitivity were investigated in genetically obese Zucker rats, an animal model of insulin resistance, using the euglycemic clamp technique. After 0.4% DHEA was administered for 10 days to female obese Zucker rats aged 16 weeks, body weight and plasma insulin decreased and glucose disposal rate (GDR), which was normally reduced in obese rats, rose significantly compared with age- and sex-matched control obese rats. On the other hand, although the pair-fed obese rats also showed levels of weight reduction similar to those of DHEA-treated rats, the increase in GDR of DHEA-treated rats was significantly greater than in pair-fed rats, suggesting a direct ameliorating effect of DHEA on insulin sensitivity of obese rats. Serum concentration of tumor necrosis factor (TNF)-alpha, one of cytokines causing insulin resistance, was also reduced significantly in DHEA-treated, but not in pair-fed obese rats. In conclusion, our results suggest that DHEA treatment reduces body weight and serum TNF-alpha independently, and that both may ameliorate insulin resistance in obese Zucker fatty rats.

Dehydroepiandrosterone Supplements: Bringing Sense to Sensational Claims

OBJECTIVE

To summarize the current information about dehydroepiandrosterone (DHEA), a steroid hormone produced in the adrenal cortex.

METHODS

The biochemical and physiologic features of DHEA and its purported effects on overall age-related decline and on various disorders are reviewed. In addition, the potential side effects from administration of DHEA are discussed.

RESULTS

During the normal life cycle, levels of DHEA fluctuate, beginning with production of large quantities in the fetus, stopping at birth, resuming during ages 5 to 7 years, and increasing throughout puberty to maximal production in the 20s. Thereafter, DHEA levels progressively decline. This age-related decline in physiologic levels of DHEA has prompted speculation about a relationship between relative "DHEA deficiency" in older age and diseases of aging as well as the possibility of deriving benefits from administration of DHEA. Certain studies in animals (primarily rodents) have suggested anticancer effects of DHEA in pharmacologic doses and improvement in metabolism. In various studies in animals and humans, discrepant results have been found in the assessment of the association between DHEA levels and coronary artery disease. Likewise, the clinical significance of changes in immune function with DHEA treatment is unknown. Because DHEA is classified as a "nutritional supplement," it is not subjected to government regulation, and a potential exists for inaccurate dosage and impurities.

CONCLUSION

Studies have shown that DHEA influences multiple systems and disease processes in animals and humans; some of these effects could be considered beneficial and others detrimental. To date, no long-term health benefits from DHEA in "replacement" doses have been demonstrated.

Dietary and hypothalamic changes in delta 4-androstenedione-treated Zucker rats

Dehydroepiandrosterone (DHEA) has been shown to alter hypothalamic monoamines and reduce energy intake (EI) in Zucker rats (ZRs). We hypothesized that a metabolite of DHEA, delta 4-Androstenedione (delta 4), may mediate these effects. Male lean and obese ZRs (LZR, OZR) were fed control chow (CC) for 7 days, during which basal EI was recorded, various concentrations of delta 4 for 7 days, during which 0.6 and 0.3% delta 4 reduced EI significantly, and CC for 7 days, which resulted in a return of EI to basal levels. After delta 4 administration, neurotransmitter contents of various hypothalamic areas were determined. Serotonin (5-HT) has been shown to be correlated with feeding inhibition, and we have shown DHEA to increase lateral hypothalamic 5-HT synthesis; however, after 1 day and 7 days of delta 4, the OZR exhibited an increased metabolism, not synthesis, of 5-HT in the lateral and paraventricular hypothalamus, respectively, delta 4 was compared to DHEA in a macronutrient self-selection study with female OZRs. One group was injected intraperitoneally (IP) with sesame oil (control), another with DHEA (100 mg/kg), and another with delta 4 (100 mg/kg). Previous studies have shown that DHEA decreases both EI and % calories from fat. In this study, delta 4 decreased % calories from fat, but did not decrease total EI. Contrary to DHEA's effect of reducing serum insulin through 28 days of treatment, delta 4 in chow reduced insulin only acutely (1 day). We conclude, based on these differences, that DHEA has unique effects not mediated by its metabolite, delta 4-Androstenedione.

Dehydroepiandrosterone (DHEA) treatment of depression

Dehydroepiandrosterone (DHEA) and its sulfate, DHEA-S, are plentiful adrenal steroid hormones that decrease with aging and may have significant neuropsychiatric effects. In this study, six middle-aged and elderly patients with major depression and low basal plasma DHEA f1p4or DHEA-S levels were openly administered DHEA (30-90 mg/d x 4 weeks) in doses sufficient to achieve circulating plasma levels observed in younger healthy individuals. Depression ratings, as well as aspects of memory performance significantly improved. One treatment-resistant patient received extended treatment with DHEA for 6 months: her depression ratings improved 48-72% and her semantic memory performance improved 63%. These measures returned to baseline after treatment ended. In both studies, improvements in depression ratings and memory performance were directly related to increases in plasma levels of DHEA and DHEA-S and to increases in their ratios with plasma cortisol levels. These preliminary data suggest DHEA may have antidepressant and promemory effects and should encourage double-blind trials in depressed patients.

A paradoxical elevation of brain cyclo(His-Pro) levels in hyperphagic obese Zucker rats

Several studies suggest a role for endogenous cyclo(His-Pro) or CHP in appetite regulation. In the present study, we have examined the regional brain distribution of CHP in hyperphagic obese Zucker rats and their lean littermates. The data show a significant elevation in the levels of CHP in many brain regions, including hypothalamus of the obese rat. Within the hypothalamus, the lateral hypothalamic (LH) nucleus of obese rats had significantly higher levels of CHP when compared to that of the lean littermates. Administration of dehydroepiandrosterone, a steroid hormone known to decrease food intake and body weight gain, to obese rats led to decrease in the levels of CHP in the LH. These data further suggest a role for the endogenous CHP in attenuating food intake.