M. Luisi

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 3&agr;,5&agr;-tetrahydroprogesterone (3&agr;,5&agr;-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 3&agr;,5&agr;-THP in both AN and BN. Therefore, we measured plasma levels of DHEA, DHEA-S, 3&agr;,5&agr;-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 3&agr;,5&agr;-THP, DHEA, DHEA-S, and cortisol but reduced concentrations of 17&bgr;-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.

Plasma brain-derived neurotrophic factor daily variations in men: correlation with cortisol circadian rhythm

Expression and secretion of neurotrophins, including brain-derived neurotrophic factor (BDNF), are regulated also by neuronal activity. Data available in the literature suggest that BDNF central levels are influenced by light and dark. Diurnal changes of BDNF mRNA and protein contents have been demonstrated in the rat central nervous system. Based on these pieces of evidence, we investigated the hypothesis of a possible diurnal variation of BDNF circulating levels in human males. Moreover, we looked for a possible correlation with cortisol circadian rhythm, since both BDNF and cortisol are implicated in the maintenance of cerebral functions. In this study, 34 healthy young male volunteers were included. Five blood samples were drawn from each subject thrice in a month at regular 4-h intervals (0800, 1200, 1600, 2000, and 2400 h). BDNF and cortisol were measured in all samples. BDNF was determined by ELISA method. Our results show that plasma BDNF levels, as well as cortisol levels, are significantly higher in the morning when compared with the night (P<0.001), with a trend of constant decrease during the day. Furthermore, plasma BDNF and cortisol are positively correlated (Spearman index=0.8466). The present study is the first to demonstrate the presence of a diurnal rhythm of BDNF in humans. Moreover, the correlation found out between BDNF and cortisol circadian trend allows us to speculate that these two factors may be physiologically co-regulated, in order to maintain the homeostasis of integrated cerebral activities.

Six-month oral dehydroepiandrosterone supplementation in early and late postmenopause

The adrenal production of the Δ5-androgens, dehydroepiandrosterone (DHEA) and its sulfate ester dehydroepiandrosterone sulfate (DHEAS), declines linearly with aging. The evidence that DHEA or DHEAS administration may alleviate some of the problems related to aging has opened new perspectives for clinical research. The present study aims to investigate the effects of a 6-month DHEA supplementation in early and late postmenopausal women, with normal or overweight body mass index (BMI), on the level of circulating steroids, sex hormone binding globulin (SHBG), β-endorphin and gonadotropins, and on the adrenal gland response to dexamethasone suppression and adrenocorticotropic hormone (ACTH) stimulation. Early postmenopausal women (50–55 years) both normal weight (BMI 20–24, n = 9) and overweight (BMI 26–30, n = 9) and late postmenopausal women (60–65 years) both of normal weight and overweight, were treated with oral DHEA (50 mg/day). Circulating DHEA, DHEAS, 17-OH pregnenolone, progesterone, 17-OH progesterone, allopregnanolone, androstenedione, testosterone, dihydrotestosterone, estrone, estradiol, SHBG, Cortisol, luteinizing hormone, follicle stimulating hormone and β-endorphin levels were evaluated monthly and a Kupperman score was performed. The product/precursor ratios of adrenal steroid levels were used to assess the relative activities of the adrenal cortex enzymes. Before and after 3 and 6 months of therapy, each women underwent an ACTH stimulating test (10 μgi.v.in bolus) after dexamethasone administration (0.5 mg p.o.) to evaluate the response of Cortisol, DHEA, DHEAS, androstenedione, 17-OH pregnenolone, allopregnanolone, progesterone and 17-OH progesterone. The between-group differences observed before treatment disappeared during DHEA administration. Levels of 17-OH pregnenolone remained constant during the 6 months. Levels of DHEA, DHEAS, androstenedione, testosterone and dihydrotestosterone increased progressively from the first month of treatment. Levels of estradiol and estrone significantly increased after the first/second month of treatment. Levels of SHBG significantly decreased from the second month of treatment only in overweight late postmenopausal women, while the other groups showed constant levels. Progesterone levels remained constant in all groups, while 17-OH progesterone levels showed a slight but significant increase in all groups. Allopregnanolone and plasma β-endorphin levels increased progressively and significantly in the four groups, reaching values three times higher than baseline. Levels of Cortisol and gonadotropins progressively decreased in all groups. The product/precursor ratios of adrenal steroid levels at the sixth month were used to assess the relative activities of the adrenal cortex enzymes and were compared to those found before therapy. The 17,20-desmolase, sulfatase and/or sulfotransferase, 11,20-lyase and 5α-reductase activities significantly increased, while the 3β-hydroxysteroid-oxidoreductase activity did not vary. On thecontrary, the 11-hydroxylase and/or 21-hydroxylase activities showed a significant decrease after 6 months of treatment. In basal conditions, dexamethasone significantly suppressed all the adrenal steroids and this suppression was greater after 3 and 6 months of treatment for DHEA, DHEAS and allopregnanolone, while it remained unchanged for other steroids. Before treatment, ACTH stimulus induced a significant response in all parameters; after the treatment, it prompted a greater response in Δ5-and Δ4-androgens, progesterone and 17-OH progesterone, while Cortisol responded less in both younger and older normal-weight women. The endometrial thickness did not show significant modifications in any of the groups of postmenopausal women during the 6 months of treatment. Treatment with DHEA was associated with a progressive improvement of the Kupperman score in all groups, with major effects on the vasomotor symptoms in the early postmenopausal women. In conclusion, the present findings confirm that DHEA supplementation produces physiological and supraphysiological modifications in steroid milieu and adrenal function. The beneficial effects of DHEA on the quality of life and in reverting the aging process may be related to changes in the release of adrenal products and/or peripheral steroids, with an increase in anxiolytic (allopregnanolone), anabolic (androstenedione, testosterone, dihydrotestosterone) and estrogenic (estrone, estradiol) molecules, a beneficial decrease in Cortisol and increase in pituitary β-endorphin production.

Progesterone and progestins: Effects on brain, allopregnanolone and β-endorphin

Abstract The increased use of hormonal therapies over the last years has led to improve the knowledge of pharmacological, biochemical and metabolic properties of several progestins and their effects in target tissues, such as the central nervous system. Progesterone and synthetic progestational agents are able to modulate the synthesis and release of several neurotransmitters and neuropeptides in response to specific physiological and pathological stimuli. While these actions may relay on differential activation of progesterone receptor or recruitment of intracellular pathways, some of the differences found between synthetic progestins may depend on the specific conversion to neuroactive steroids, such as the 3-α, 5-α reduced metabolite, allopregnanolone. This is a potent endogenous steroid that rapidly affects the excitability of neurons and glia cells through direct modulation of the GABA-A receptors activity exerting hypnotic/sedative, anxiolytic, anaesthetic and anticonvulsive properties. Estrogens increase the CNS and serum levels of allopregnanolone and the addition of certain but not all synthetic progestins determines a further increase in allopregnanolone levels, suggesting that the metabolism into this reduced product is related to the chemical structure of progestin molecule used. In addition, depending on specific progestin molecule used, different interaction are found with the estradiol-induced beta-endorphin synthesis and release, showing that diverse progestins have specific and divergent actions on the opiatergic system. These results highlight the concept that natural and synthetic progesterone receptor agonists may systematically induce different biological actions in CNS. This may have far-reaching implications for the clinical effects and related indications of each compound.

Daily variation of brain-derived neurotrophic factor and cortisol in women with normal menstrual cycles, undergoing oral contraception and in postmenopause

BACKGROUND Plasma brain-derived neurotrophic factor (BDNF) levels are associated with the hormonal status of women. Moreover, the suprachiasmatic nucleus appears to be implicated in the modulation of BDNF central levels. We aimed to investigate whether BDNF circadian rhythms exist in women and if there is a relationship with cortisol circadian rhythmicity. Moreover, we aimed to establish whether the hormonal status influences BDNF diurnal variations. METHODS A total of 30 women were studied: 10 fertile ovulatory women, 10 women undergoing oral contraceptive (OC) therapy and 10 post-menopausal women. Basal BDNF and estradiol levels were assayed in blood samples collected after overnight fasting at regular intervals (08:00, 12:00, 16:00, 20:00, 24:00). BDNF and cortisol levels were measured in samples collected during the follicular and luteal phases in ovulatory women and once a month in OC and post-menopausal women. RESULTS Luteal BDNF levels were significantly higher than follicular levels in fertile women (P < 0.001). In OC women, BDNF levels were similar to the follicular BDNF levels, whereas in post-menopausal women, they were significantly lower (P < 0.001). BDNF showed a diurnal rhythm in the follicular phase and in women undergoing OC, although the diurnal rhythm was blunted in the luteal phase. In post-menopausal women, BDNF and cortisol levels significantly decreased during the day. CONCLUSIONS BDNF has a diurnal variation in women that is somewhat analogous to cortisol variation; however, the amplitude of the variation in BDNF levels appears to be influenced by ovarian function. Interactions between BDNF, the hypothalamus-pituitary-adrenal axis and sex steroids might play a critical role in the human homeostasis and adaptation.

Endocrinology of menopausal transition and its brain implications.

The central nervous system is one of the main target tissues for sex steroid hormones, which act on both through genomic mechanisms, modulating synthesis, release, and metabolism of many neuropeptides and neurotransmitters, and through non-genomic mechanisms, influencing electrical excitability, synaptic function, morphological features, and neuron-glia interactions. During the climacteric period, sex steroid deficiency causes many neuroendocrine changes. At the hypothalamic level, estrogen withdrawal gives rise to vasomotor symptoms, to eating behavior disorders, and altered blood pressure control. On the other hand, at the limbic level, the changes in serotoninergic, noradrenergic, and opioidergic tones contribute to the modifications in mood, behavior, and nociception. Hormone replacement therapy (HRT) positively affects climateric depression throughout a direct effect on neural activity and on the modulation of adrenergic and serotoninergic tones and may modulate the decrease in cognitive efficiency observed in climaterium. The identification of the brain as a de novo source of neurosteroids, suggests that the modifications in mood and cognitive performances occurring in postmenopausal women may also be related to a change in the levels of neurosteroids. These findings open new perspectives in the study of the effects of sex steroids on the central nervous system and on the possible use of alternative and/or auxiliary HRT.

Changes of Serum Allopregnanolone Levels in the First 2 Years of Life and during Pubertal Development

Allopregnanolone is the best characterized among neurosteroids, and its role in the control of neuroendocrine axes has attracted increasing interest recently. However, there is no available information about circulating levels of allopregnanolone during infancy, childhood and puberty. We studied two groups of children: 1) those aged between 0 and 2 y (n = 72), and 2) those aged between 6 and 18 y, at different Tanners stages (n = 82). In each of these patients, serum allopregnanolone, progesterone, cortisol, and dehydroepiandrosterone levels were evaluated after informed consent; allopregnanolone was measured by RIA after acid extraction on cartridge. There was no significant variation of serum allopregnanolone levels either in male and female children during the first 2 y of life. Furthermore, although serum dehydroepiandrosterone levels showed a significant decrease, inversely correlated with age of the children (p < 0.01), serum cortisol and progesterone levels showed a significant age-related increase during the first 2 y of life. Cortisol and allopregnanolone levels were positively correlated (p < 0.01). During puberty, we observed a progressive increase in serum allopregnanolone levels in both boys and in girls, which were higher at Tanners stage IV-V (0.7 ± 0.01 nM; mean ± SEM) than at stages I-II (0.32 ± 0.02 nM; p < 0.01); mean levels were significantly higher at puberty than in the first 2 y of life (p < 0.01). Furthermore, during puberty, serum progesterone and dehydroepiandrosterone levels also increased progressively with age in both boys and girls. Allopregnanolone and dehydroepiandrosterone levels were positively correlated throughout puberty. The present results indicate that serum allopregnanolone levels do not change during the first 2 y of life but increase during pubertal development, suggesting that this steroid may be involved in the adaptive neuroendocrine mechanisms related to puberty.

Effects of estradiol and raloxifene analog on brain, adrenal and serum allopregnanolone content in fertile and ovariectomized female rats.

Allopregnanolone is a neuroactive steroid synthesized in rat gonads, adrenal cortex, and central nervous system. It has been suggested that sex steroid hormones might influence allopregnanolone concentrations but no clear data have ever been reported. The aim of the present study was to investigate the effects of administration of 17β-estradiol (17β-E2), the raloxifene analog LY-117018 or their combination on allopregnanolone levels in fertile and ovariectomized (OVX) rats. Thirteen groups of 12 Wistar female rats each received either 17β-E2 (0.1 or 1 µg/day) or LY-117018 (25, 250, and 1,250 µg/day), or 17β-E2 1 µg/day plus LY-117018: 25, 250, and 1,250 µg/day for 14 days. The rats were then sacrificed and allopregnanolone content was assessed in the hypothalamus, hippocampus, pituitary, adrenals, and serum. Ovariectomy determined a significant decrease in allopregnanolone content in the hypothalamus, hippocampus, pituitary, and serum, while increasing it in the adrenals (p < 0.01). In OVX rats, the administration of either 17β-E2 or LY- 117018 restored ovariectomy-induced allopregnanolone changes. The administration of LY-117018 in addition to 17β-E2 to OVX animals suppressed the increase in allopregnanolone levels determined by 17β-E2 in the hippocampus, hypothalamus, and pituitary, but not in the adrenals and serum. In fertile rats, the administration of LY-117018 reproduced the effects of ovariectomy. This study shows that the raloxifene analog LY-117018 has an estrogen-like action on the central nervous system of OVX rats when administered alone, while it acts as an antiestrogen in the presence of 17β-E2, both in OVX animals treated with 17β-E2 and in fertile rats. A different effect was observed in the adrenal glands. The mechanism of action of this compound has still to be clarified.

Progesterone and Medroxyprogesterone Acetate Effects on Central and Peripheral Allopregnanolone and Beta-Endorphin Levels

The increased use of hormonal therapies has led to the study of the properties of different progestin molecules and their effects on the central nervous system. The central and peripheral levels of neurosteroid allopregnanolone and the opioid peptide β-endorphin (β-END) are regulated by estrogens. The aim of the present study was to investigate the effects of a 2-week oral treatment with micronized progesterone or medroxyprogesterone acetate (MPA) alone or in addition to estradiol valerate (E2V) on central and peripheral allopregnanolone and β-END levels in ovariectomized (OVX) female rats. Thirteen groups of Wistar OVX rats received one of the following treatments: oral progesterone (2, 4 or 8 mg/kg/day); oral MPA (0.05, 0.1 or 0.2 mg/kg/day); E2V (0.05 mg/kg/day); E2V + progesterone (0.05 mg/kg/day + 2, 4 or 8 mg/kg/day), or E2V + MPA (0.05 mg/kg/day + 0.05, 0.1 or 0.2 mg/kg/day) for 14 days. One group of fertile and one group of OVX rats were used as controls. The concentration of allopregnanolone was assessed in the frontal and parietal lobes, hypothalamus, hippocampus, anterior pituitary, adrenals and serum, while the β-END content was assessed in the frontal and parietal lobes, hypothalamus, hippocampus, anterior and neurointermediate pituitary, and plasma. E2V administration reverted the ovariectomy-induced reduction in allopregnanolone and β-END. Progesterone and MPA increased allopregnanolone levels in all tissues except in the adrenal gland. The combined administration of progesterone or MPA and E2V determined a further increase in allopregnanolone levels with respect to E2V alone except in the adrenal gland and hippocampus only after MPA treatment. Progesterone did not affect β-END levels in the frontal and parietal lobes, hippocampus and anterior pituitary, while it caused an increase plasma, hypothalamic and neurointermediate pituitary β-END levels. MPA only affected β-END levels in the hippocampus and in the neurointermediate lobe. The combined administration of progesterone or MPA and E2V did not alter the effect of estradiol or it determined a further dose-dependent increase in β-END levels. In conclusion, this study demonstrates that progesterone and MPA have a similar but not identical effect on central and peripheral allopregnanolone and β-END levels. Their association with an estrogenic compound does not interfere with the positive effects produced by estrogen on allopregnanolone and β-END brain content.

Long-term low-dose dehydroepiandrosterone replacement therapy in aging males with partial androgen deficiency.

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) age-related withdrawal is very likely to be involved in the aging process and the onset of age-related diseases, giving rise to the question of whether preventing or compensating the decline of these steroids may have endocrine and clinical benefits. The aim of the present trial was to evaluate the endocrine, neuroendocrine and clinical consequences of a long-term (1 year), low-dose (25 mg/day) replacement therapy in a group of aging men who presented the clinical characteristics of partial androgen deficiency (PADAM). Circulating DHEA, DHEAS, androstenedione, total testosterone and free testosterone, dihydrotestosterone (DHT), progesterone, 17-hydroxyprogesterone, allopregnanolone, estrone, estradiol, sex hormone binding globulin (SHBG), cortisol, follicle stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels were evaluated monthly to assess the endocrine effects of the therapy, while β-endorphin values were used as a marker of the neuroendocrine effects. A Kupperman questionnaire was performed to evaluate the subjective symptoms before and after treatment. The results showed a great modification of the endocrine profile; with the exception of cortisol levels, which remained unchanged, DHEA, DHEAS, androstenedione, total and free testosterone, DHT, progesterone, 17-hydroxyprogesterone, estrone, estradiol, GH, IGF-1 and β-endorphin levels increased significantly with respect to baseline values, while FSH, LH and SHBG levels showed a significant decrease. The Kupperman score indicated a progressive improvement in mood, fatigue and joint pain. In conclusion, the present study demonstrates that 25 mg/day of DHEA is able to cause significant changes in the hormonal profile and clinical symptoms and can counteract the age-related decline of endocrine and neuroendocrine functions. Restoring DHEA levels to young adult values seems to benefit the age-related decline in physiological functions but, however promising, placebo-controlled trials are required to confirm these preliminary results.