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Introduction: Estetrol (E4), a naturally occurring estrogen only produced by the human fetal liver, is being evaluated in human studies for potential use in contraception and menopausal care. The present study was designed to profile E4 in the central nervous system, to assess the in vivo effects of E4 administration on allopregnanolone (AP) synthesis in specific brain structures and to evaluate whether E4 has synergic or antagonistic effects on estradiol-mediated AP synthesis., Material and Methods: Intact female adult rats received different doses of E4, and ovariectomized OVX rats received different doses of E4 or E2V or combinations of both drugs. The concentrations of AP were assessed in the frontal and parietal cortex, hippocampus, hypothalamus, anterior pituitary, and serum., Results: E4 did not alter AP in intact animals in any region. E4 at a dosage of 5mg/kg/day increased AP levels in different brain areas and in the serum of OVX animals. However, in the presence of estradiol, E4 showed an estrogen-antagonistic effect on the brain and serum levels of AP., Conclusion: E4 increases the CNS and peripheral levels of AP, behaving as a weak estrogen-agonist in OVX rats. The antagonistic effect observed with E2V co-administration further profile E4 as a natural SERM., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Weight gain is a well-known unwanted effect of valproic acid (VPA) therapy. Studies on VPA-associated changes of homeostatic hormones remain limited and controversial. Allopregnanolone (AP) is a circulating neuroactive steroid involved in modulation of behavioral activities whose serum levels are increased in obese children. The aim of the present study was to determine whether VPA therapy affects leptin and AP circulating levels in prepubertal girls with epilepsy. One-hundred and one patients were divided into four groups: epileptic patients with VPA-associated obesity (n = 21); lean epileptic patients under VPA therapy (n = 35); healthy obese children (n = 23), and healthy lean children (n = 22). Patients with VPA-associated obesity had significantly enhanced blood concentrations of AP (p = 0.001) and leptin (p = 0.007) than lean subjects. There were no differences in leptin and AP plasma levels between patients with VPA-associated obesity and obese controls (p = 0.45 and p = 0.10, respectively), as there were no differences between lean patients under VPA therapy and lean healthy controls (p = 0.06). In patients under VPA therapy, both plasma leptin and AP levels were significantly correlated with BMI (r = 0.074, p = 0.02, and r = 0.084, p = 0.01, respectively). Plasma leptin concentrations were not correlated with AP levels (r = 0.023, p = 0.13). In conclusion, a correlation between obesity and neuroactive steroids was shown. It remains to be established whether the increased circulating level of AP is a secondary effect of anxiolytic-sedative processes occurring in subjects with obesity-related emotional and behavioral anomalies, or plays a central role in determining abnormal eating behaviors., (Copyright © 2010 S. Karger AG, Basel.)

Background: Allopregnanolone, a neuroactive steroid mainly secreted by adrenals and gonads, is a hormone that seems to play a role in precocious puberty, as demonstrated by its high baseline levels found in girls with central precocious puberty (CPP). Allopregnanolone concentrations significantly increase after GnRH and ACTH stimulation test suggesting both its ovarian and adrenal production., Aim: Aim of this study was to evaluate allopregnanolone concentrations after GnRH and GnRH agonist analog stimulation test in girls with CPP to better establish its secretion source., Subjects and Methods: Gonadotropins and steroid hormones were evaluated in different days after GnRH and triptorelin stimulation test in 15 CPP girls., Results: After GnRH stimulation, LH, FSH, and allopregnanolone concentrations significantly increased (p<0.05). After triptorelin administration LH, FSH, estradiol and DHEAS levels significantly increased (p<0.05), while allopregnanolone concentrations significantly decreased (1.08±0.24 vs 0.87±0.28 nmol/l; p=0.003)., Conclusions: The different response of allopregnanolone to GnRH and GnRH agonist analog might reflect the agonist and antagonist action exerted by these secretagogues. Our data suggest the prevalent gonadal allopregnanolone production in CPP subjects and the usefulness of its measurement in the diagnosis of CPP.

Objective: To investigate the adrenal response in terms of allopregnanolone secretion in a group of hyperinsulinemic patients with polycystic ovary syndrome (PCOS)., Design: Controlled clinical study., Setting: Patients with PCOS in a clinical research environment., Patients: Twenty-two overweight patients with PCOS with hyperinsulinism were enrolled after informed consent., Interventions: All patients underwent hormonal evaluations, oral glucose tolerance test (OGTT) and adrenocorticotropic hormone (ACTH) test before and after 4 months of metformin administration (500 mg p.o. bi-daily). Ultrasound examinations and Ferriman-Gallway score were also performed. Main outcome measures. plasma luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), estradiol, 17-hydroxy-progesterone (17OHP), androstenedione (A), testosterone (T), allopregnanolone, glucose, insulin, C peptide concentrations, body mass index (BMI)., Results: Metformin administration reduced significantly LH, A, T, insulin and BMI, while allopregnanolone was significantly increased with no change in progesterone plasma levels. Insulin response to OGTT decreased and allopregnanolone response to ACTH stimulation before while this was restored after the treatment interval. The Ferriman-Gallway score as well as the ovarian volume was significantly decreased after 4 months of metformin therapy., Conclusions: In overweight patients with PCOS with hyperinsulinism, allopregnanolone secretion is impaired and metformin administration restored normal allopregnanolone concentrations modulating both steroid syntheses from the ovaries and from adrenal gland.

Objective: The natural selective estrogen receptor modulator DT56a (Femarelle), derived from soybean, has been shown to relieve menopausal vasomotor symptoms with no effect on sex steroid hormone levels or endometrial thickness.The purpose of the present study was to evaluate the neuroendocrine effect of DT56a administration through the evaluation of brain content of allopregnanolone (AP), an endogenous neurosteroid gamma-aminobutyric acid agonist with anxiolytic properties, and through the assessment of beta-endorphin (beta-END), the endogenous opioid implicated in pain mechanism, emotional state, and autonomic control., Methods: Five groups of Wistar ovariectomized (OVX) rats received one of the following treatments: oral DT56a administration at doses of 6, 12, 60, and 120 mg kg(-1) day(-1) or estradiol valerate (E2V) at a dose of 0.05 mg kg(-1) day(-1) for 14 days. One group of fertile and one group of OVX rats receiving placebo were used as controls. The concentration of AP was assessed in the frontal and parietal cortex, hippocampus, hypothalamus, anterior pituitary, and serum, whereas the content of beta-END was evaluated in the frontal and parietal cortex, hippocampus, hypothalamus, neurointermediate lobe, anterior pituitary, and plasma., Results: DT56a increased AP levels in all brain areas analyzed and in serum, with a classical dose-related curve in comparison with OVX rats. In some brain areas, such as the frontal cortex, the parietal cortex, and the anterior pituitary, positive results were found even with the administration of a lower DT56a dose of 60 mg kg(-1) day(-1), attaining AP levels in the range of those in animals treated with E2V. Similarly, beta-END levels were enhanced in selected brain areas such as the hippocampus, the hypothalamus, the neurointermediate lobe, and the anterior pituitary in comparison with those in OVX rats, in which the increase of the opioid was dose related and in the range of those in rats treated with E2V., Conclusions: This study demonstrated that DT56a positively affects brain neurosteroidogenesis and the opiatergic system: DT56a exerts an estrogen-like effect on selective areas related to mood, cognition, and homeostasis control, presenting a specific pattern of interaction with the brain function. These findings may, in part, explain the clinical effect of DT56a on menopausal symptoms.

The aim of the present study was to evaluate the potential action of Nestorone (alone or in combination with estradiol valerate) on the level of allopregnanolone and of the opioid beta-endorphin in selected brain areas. Wistar ovariectomized rats were given 0.05 mg/(kg day) of estradiol valerate (E2V) or subcutaneous Nestorone at three dose levels: low dose (10 microg/(kg day)), antiovulatory dose (50 micro/(kg day)) and high dose (250 microg/(kg day)) with and without E2V. E2V therapy reversed the reduction of allopregnanolone and beta-endorphin induced by ovariectomy anywhere was analyzed except for the adrenal gland. Nestorone showed no effect on allopregnanolone concentration in serum or any part of the brain tissue when given alone while it had a synergistic increasing effect in allopregnanolone concentration in some parts of the brain (hippocampus, hypothalamus, anterior pituitary and serum) when given at high dose of 250 microg/(kg day) in combination with E2V. At lower doses it possesses a synergistic effect with E2V only in the hippocampus (at 50 microg/(kg day)) and in the anterior pituitary (at 10 and 50 microg/(kg day)). Nestorone administered alone at any dose led to significant increase in beta-endorphin levels in the hippocampus only while, in the high dose group, there was a significant increase in endorphin levels in anterior pituitary and hypothalamus in addition to hippocampus as compared to ovariectomized control rats. In addition, only the highest dose of Nestorone added to estrogen increased beta-endorphin levels of hippocampus and plasma. Thus the lower doses of Nestorone alone or in combination with estrogen do not seem to exert any great effect on both allopregnanolone and beta-endorphin. It is only the highest dose of Nestorone that increases allopregnanolone and beta-endorphin levels in selected brain areas, which are the hippocampus, the hypothalamus, the anterior pituitary and serum/plasma. This suggests that Nestorone at the antiovulatory dose levels may not alter the positive effects of estrogen treatment on mood and behaviour.

Background: Synthetic progestins may have different biological actions depending on the target tissue, the dose administered or the coadministration of an estrogen molecule. The purpose of the present study was to evaluate the neuroendocrine effect of chlormadinone acetate (CMA) administration, analyzing the brain content of allopregnanolone (ALLO), an endogenous neurosteroid gamma-aminobutyric acid agonist with anxiolytic properties, and the brain level of beta-endorphin (beta-END), an endogenous opioid implicated in pain mechanism, emotional state and autonomic control., Study Design: Seven groups of Wistar ovariectomized (OVX) rats received one of the following treatments: oral CMA at a dose of 0.1, 0.5 or 1 mg/kg per day; estradiol valerate (E(2)V) at a dose of 0.05 mg/kg per day; CMA plus E(2)V (CMA 0.1 or 0.5 or 1 mg/kg per day + E(2)V 0.05 mg/kg per day) for 14 days. One group of fertile rats and one group of OVX rats were used as controls., Results: CMA increased ALLO content in the hippocampus and, when it was administered with E(2)V, also in the hypothalamus and anterior pituitary, evidence of a synergic effect with estrogens only in selective brain areas. beta-END content increased in the neurointermediate lobe and anterior pituitary after CMA administration, and it did not antagonize the positive, estrogen-induced increase of beta-END level., Conclusion: CMA is effective in increasing ALLO and beta-END in selective brain areas showing a specific pattern of interaction with brain function, different compared to progesterone or to other synthetic progestins. In particular, CMA action on part of the limbic system (hippocampus and hypothalamus) and on the anterior pituitary support the hypothesis that this progestin might affect cognitive function, emotional state and autonomic control.

Introduction: Clinical and biological evidences have shown a wide range of neuroactive effects of testosterone administration., Aim: Evaluation of the effects of 2-weeks treatment with testosterone (T), Dihydrotestosterone (DHT), and estradiol valerate (E2V) on brain and serum allopregnanolone (AP) in gonadectomized rats of both sexes., Main Outcome Measures: AP levels were measured in frontal and parietal lobe, hippocampus, hypothalamus, anterior pituitary, and in serum., Methods: Eight groups of Wistar female and eight groups of Wistar male rats were included. For each sex, one group of fertile and one group of gonadectomized rats were employed as control receiving placebo. The others groups received subcutaneous T at the dose of 10 microg/kg/day and 100 microg/kg/day for female rats, and 1 mg/kg/day and 5 mg/kg/day for male rats, or DHT at the doses of 1 microg/kg/day, 10 microg/kg/day, and 100 microg/kg/day for females, and 0, 1 microg/kg/day, 1 mg/kg/day and 5 mg/kg/day for males, or E2V (0.05 mg/Kg/day)., Results: Ovariectomy (OVX) and orchidectomy (OCX) induced a significant decrease in AP in all brain areas analyzed, as well as in serum. In OVX rats, T replacement, as well as E2V, significantly increased AP content in all brain areas and in plasma. In OCX, T and E2V did not actively result in influencing AP concentration in frontal and parietal lobe, while it produced a significant rise in AP levels in the hippocampus, hypothalamus, anterior pituitary, and serum. Conversely, DHT replacement had no affect on AP levels anywhere or at any administered dose, either in males or in female rats., Conclusions: Gender difference and T therapy affect brain AP synthesis/release during the reproductive aging. This effect becomes particularly evident in the brain of ovariectomized animals, where the content of this specific neurosteroid is much more responsive than male animals to testosterone replacement.

Objective: To investigate the effects of dydrogesterone (DYD), a synthetic progestin largely used in hormone therapy, on the central nervous system by studying two markers of the neuroendocrine function: the neurosteroid allopregnanolone and the opioid beta-endorphin., Design: Experimental study on animal model., Setting: Academic research environment., Animal(s): 72 Wistar female rats., Intervention(s): One group of fertile and one of ovariectomized rats (receiving placebo) were used as control. After ovariectomy, the rats underwent a 2-week oral treatment of DYD (0.2, 0.6, or 1.0 mg/kg per day), alone or with estradiol valerate (E2V; 0.05 mg/kg per day)., Main Outcome Measure(s): Allopregnanolone and beta-endorphin, assessed in different brain areas and in circulation., Result(s): Ovariectomy decreased allopregnanolone anywhere except in the adrenal gland and reduced beta-endorphin central levels; E2V reversed the effects of ovariectomy; and DYD (1 mg/kg per day) increased allopregnanolone levels in frontal lobe, hippocampus, and hypothalamus. Combined administration of DYD at 1 mg/kg per day plus E2V determined a further increase of allopregnanolone levels in frontal lobe, hippocampus, hypothalamus, and serum. Dydrogesterone did not modify the levels of beta-endorphin induced by E2V., Conclusion(s): Dydrogesterone interacts with allopregnanolone levels (less with beta-endorphin), and it can be considered important modulator of the neuroendocrine function.

The aim of this study was to investigate the effects of nomegestrol acetate (NOMAc) on the central nervous system by analyzing the neurosteroid allopregnanolone and the opioid beta-endorphin (beta-endorphin). 104 Wistar female rats were used in this study; one group of fertile and one group of ovariectomized rats were used as control. The others were ovariectomized and they underwent a 2-week oral treatment of NOMAc (0.05, 0.1, 0.2, 0.5, 1mg/kg/day), alone or with 0.05 mg/kg/day of estradiol valerate (E2V). Allopregnanolone and beta-endorphin were assessed in different brain areas and in circulation. Ovariectomy decreased allopregnanolone anywhere except in the adrenal gland and E2V reversed the effects of ovariectomy. 0.5 and 1mg/kg/day of NOMAc increased allopregnanolone levels in hippocampus. Combined administration of 1mg/kg/day of NOMAc plus E2V induced a further increase of allopregnanolone levels in hippocampus, hypothalamus, and anterior pituitary. NOMAc (1mg/kg/day) decreased the adrenal content of allopregnanolone, both by itself and associated with E2V. NOMAc increased hippocampal and hypothalamic content of beta-endorphin at the highest doses, and it increased positively E2V action, at 1mg/kg/day, also in anterior pituitary and plasma. These findings reinforce the clinical data regarding the capability of NOMAc to modulate the pathways involved in mood and behaviour. In fact, due to the NOMAc action on hippocampus, hypothalamus, and anterior pituitary, our results highlight the selectivity of NOMAc on part of the limbic system and the anterior pituitary, regarding both allopregnanolone and beta-endorphin.

Objective: Several studies demonstrated that obese subjects have a hyperactive hypothalamic-pituitary-adrenal axis and that sex steroid hormones have been closely related to the regulation of adiposity, either through direct or indirect physiological mechanisms. Allopregnanolone (3alpha-hydroxy-5alpha-pregn-20-one; AP) is a circulating neuroactive steroid hormone involved in the modulation of behavioral functions, stress and neuroendocrine axis. The aim of our study was to evaluate basal serum AP levels in obese children., Subjects and Measurements: We studied 27 normal weight (NW) and 23 overweight (OW) girls. Gonadotropins and steroid hormones were assessed in all patients., Results: Basal AP concentrations in OW girls were significantly higher than in NW controls (P=0.013). There was no difference found between the other gonadal and adrenal hormones. Considering the pubertal stage, we demonstrated that obese pubertal girls presented higher AP concentrations than prepubertal and pubertal NW ones (P=0.020), and higher dehydroepiandrosterone sulfate (DHEAS) levels with respect to prepubertal obese girls, and prepubertal and pubertal NW patients (P=0.025). AP and DHEAS were significantly directly related to weight (r=0.31 and r=0.54, respectively) and body mass index (r=0.29 and r=0.34, respectively). In pubertal OW girls, a significant positive correlation between AP and DHEAS (r=0.60), A (r=0.72) and luteinizing hormone (r=0.64) levels was demonstrated., Conclusion: The present study demonstrates that AP is hypersecreted in children and adolescent with OW involving DHEAS concentrations, too. Our data suggest a possible role of AP in the regulation of neuroendocrine axis related to obesity. We can also speculate that in OW girls, who could manifest emotional and behavioral problems, a part of higher levels of this neuroactive steroid might act as gamma-aminobutyric acid agonist producing anxiolytic-sedative effects.

Objective: Drospirenone is the unique progestin derived from 17-spironolactone used for contraception and hormone therapy. Few data are available concerning the effects of drospirenone on the central nervous system and neuroendocrine milieu. The opioid beta-endorphin and the neurosteroid allopregnanolone are considered markers of neuroendocrine functions, and their synthesis and activity are regulated by gonadal steroids. The aim of the present study was to evaluate the effect of a 2-week oral treatment with drospirenone, estradiol valerate, and combined therapy of drospirenone + estradiol valerate on central and peripheral beta-endorphin and allopregnanolone levels in ovariectomized female rats., Design: Seven groups of Wistar ovariectomized rats received oral drospirenone (0.1, 0.5, and 1.0 mg/kg per day), estradiol valerate (0.05 mg/kg per day), or drospirenone (0.1, 0.5, and 1.0 mg/kg per day) + estradiol valerate (0.05 mg/kg per day). One group of fertile and one group of ovariectomized rats were used as controls. beta-endorphin levels were measured in frontal and parietal lobes, hippocampus, hypothalamus, anterior and neurointermediate pituitary, and plasma, and allopregnanolone content was assessed in frontal and parietal lobes, hippocampus, hypothalamus, anterior pituitary, adrenal glands, and serum., Results: Ovariectomy induced a significant decrease in beta-endorphin and allopregnanolone content in all brain areas analyzed and in circulating levels, whereas it increased allopregnanolone content in the adrenal gland. Estradiol valerate replacement increased beta-endorphin and allopregnanolone levels in all brain areas analyzed and in plasma/serum. Drospirenone treatment significantly increased beta-endorphin levels in all brain areas analyzed (with the only exception being the parietal lobe), whereas it produced no effect on allopregnanolone levels. The addition of drospirenone to estradiol valerate did not modify the effects of estradiol valerate on beta-endorphin or allopregnanolone levels. Drospirenone showed an additive and synergistic effect with estradiol in the neurointermediate lobe on beta-endorphin synthesis., Conclusions: Drospirenone significantly increases central and circulating beta-endorphin levels and does not seem to interfere with allopregnanolone production.

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 beta-endorphin (beta-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 beta-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 beta-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 beta-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 beta-END levels in the frontal and parietal lobes, hippocampus and anterior pituitary, while it caused an increase plasma, hypothalamic and neurointermediate pituitary beta-END levels. MPA only affected beta-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 beta-END levels. In conclusion, this study demonstrates that progesterone and MPA have a similar but not identical effect on central and peripheral allopregnanolone and beta-END levels. Their association with an estrogenic compound does not interfere with the positive effects produced by estrogen on allopregnanolone and beta-END brain content.

Objective: We evaluated the effects of tibolone oral administration on neuroendocrine function by investigating the modulation exerted by tibolone administration on allopregnanolone and central and peripheral beta-endorphin (beta-EP) levels in ovariectomized rats., Design: Female Wistar rats (N = 64) were included: 48 rats were ovariectomized, 8 cycling rats were included as controls, and 8 cycling rats were treated with placebo. The ovariectomized animals were divided into six groups: untreated rats and those that received 14-day oral treatment with either placebo, estradiol valerate (E2V) 0.05 mg/kg/d, or tibolone (0.1, 0.5, or 2 mg/kg/d. beta-EP levels were assessed in the frontal lobe, parietal lobe, hippocampus, hypothalamus, anterior pituitary, neurointermediate pituitary, and plasma, whereas allopregnanolone levels were measured in the frontal lobe, parietal lobe, hippocampus, hypothalamus, anterior pituitary, adrenal glands, and serum., Results: The administration of tibolone (0.5 and 2 mg/kg/d) in ovariectomized rats induces a significant increase of allopregnanolone in the frontal lobe, parietal lobe, hippocampus, hypothalamus, whereas in serum a significant increase of allopregnanolone occurs only with the dose of 2 mg/kg/d, a significant decrease in allopregnanolone levels occurs in the adrenal glands. No changes occurred in the anterior pituitary. Tibolone doses of 0.5 and 2 mg/kg/d induced a significant increase in beta-EP content in the frontal lobe, hypothalamus, and neurointermediate lobe; and, at doses of 2 mg/kg/d, in the parietal lobe, anterior pituitary, and plasma, without changes in the hippocampus. Compared with E2V, 0.5 mg/kg/d tibolone showed a similar effect on allopregnanolone and beta-EP in most brain regions., Conclusions: Tibolone administration affects beta-EP and allopregnanolone levels, playing a role as a neuroendocrine modulator.

Allopregnanolone, a neuroactive steroid, increases during pubertal development and high concentrations are present in subjects with precocious puberty. The aim of the present study was to evaluate serum allopregnanolone levels in girls with precocious pubarche (PP). Basal gonadotropins and steroid hormones were assessed in 17 girls with PP, 22 girls with central precocious puberty (CPP), 25 girls with normal puberty at the same pubertal stage of CPP ones, and 17 prepubertal girls. Adrenocorticotropin hormone (ACTH) and gonadotropin-releasing hormone (GnRH) stimulation tests were performed in all subjects with PP, and in 12 out of 22 with CPP. All girls with normal puberty underwent to GnRH test, while ACTH test was performed in 17 out of 25. Basal dehydroepiandrosterone sulfate (DHEAS) concentrations resulted significantly higher in PP and normal pubertal girls than in prepubertal ones. Allopregnanolone, gonadotropins and estradiol levels were significantly lower in PP group with respect to CPP (P<0.05), while they were comparable among PP, normal pubertal and prepubertal groups. After ACTH administration, allopregnanolone concentrations significantly increased in all groups (P<0.05). After GnRH stimulation, its levels significantly increased in CPP and normal pubertal controls (P<0.05), while no incremental rise was found in PP girls. In conclusion, our study shows that in girls with PP basal and GnRH-stimulated levels of allopregnanolone are significantly lower than in CPP girls. These data suggest that this neurosteroid may be considered a new marker of pubertal development.

Objective: To evaluate the effects of dehydroepiandrosterone (DHEA) oral administration on neuroendocrine function by investigating the modulation exerted by DHEA administration on allopregnanolone and beta-endorphin (beta-EP) central and peripheral levels in ovariectomized rats., Design: Prospective study., Setting(s): Experimental research environment., Animal(s): Female Wistar rats (n = 48)., Intervention(s): Forty rats were ovariectomized and received an oral treatment with either placebo or 0.5, 1, or 2 mg/kg/day of DHEA. After euthanization, beta-EP levels were measured in hippocampus, hypothalamus, anterior pituitary, neurointermediate pituitary, and plasma. Allopregnanolone and DHEAS levels were measured in hippocampus, hypothalamus, anterior pituitary, adrenal glands, and serum. Serum E(2) concentration was also measured., Main Outcome Measure(s): Dehydroepiandrosterone sulfate ester (DHEAS), E(2), beta-EP, and allopregnanolone levels., Result(s): Dehydroepiandrosterone administration increased DHEAS content in all organs and serum, except for anterior pituitary, where no significant changes occurred. DHEA administration in ovariectomized animals did not significantly increase E(2) circulating levels. DHEA administration induced an increase in allopregnanolone and beta-EP content in hippocampus, hypothalamus, and anterior pituitary and in serum or plasma., Conclusion(s): Dehydroepiandrosterone administration in ovariectomized animals increased allopregnanolone and beta-EP central and peripheral levels, which suggests that this compound may play a role as a neuroendocrine mediator, possibly substantiating the beneficial effects of postmenopausal DHEA therapy on the central nervous system.

The aim of the present study was to evaluate, in healthy postmenopausal women, the impact of tibolone (2.5 mg), transdermal estradiol (50 microg) (TE) and different oral estrogen-progestin regimens, conjugated equine estrogens (0.625 mg) plus medroxyprogesterone acetate (5 mg) (CEE + MPA) and estradiol (2 mg) plus norethisterone acetate (1 mg) (E2 + NETA) on circulating estradiol, progesterone, allopregnanolone, cortisol and dehydroepiandrosterone (DHEA) levels. Blood samples were collected before and after 1, 3, 6 and 9 months of treatment in 85 postmenopausal women. Estradiol levels increased (p < 0.001) in the TE, CEE + MPA and E2 + NETA groups after 1 month of therapy, but did not change in the tibolone group during the entire follow-up period. Both E2 + NETA and tibolone treatments induced an increase in progesterone levels (p < 0.05) after 1 year of therapy. Allopregnanolone levels showed an increase in all estrogen-based groups, being significant after 3 months of treatment (p < 0.01). Patients receiving tibolone showed a significant increase in allopregnanolone levels at 3 months (p < 0.05), but lower than in the other groups. Cortisol levels decreased significantly in the TE and CEE + MPA groups after 6 months and 12 months of treatment, respectively. Neither tibolone nor E2 + NETA treatments modified circulating cortisol levels. DHEA levels significantly (p < 0.05) decreased after 6 months of TE or estrogen-progestin therapies independently of the presence or the type of progestin used. In contrast, DHEA remained stable throughout the 12 months of treatment with tibolone. The increase of allopregnanolone, a steroid with sedative and anxiolytic properties, in response to these different treatments could underlie, at least in part, the central effects that hormone replacement therapy and tibolone have on anxiety, mood and behavior. Unlike estrogen-based therapy, tibolone treatment did not reduce the DHEA milieu in the menopause, and thus did not enhance the androgen deficiency syndrome in postmenopausal women.

Objective: To compare beta-endorphin and allopregnanolone levels and their response to a 2-week oral estrogen treatment with conjugated equine estrogens (CEE) in young ovariectomized (ovx) and in healthy aged female rats., Design: Prospective study., Setting: Animal laboratory in an academic environment., Animal(s): Twenty-four young ovx and 24 healthy aged female Wistar rats were treated with CEE. Three 8-rat control groups (cycling, ovx, and aged rats) were also included., Intervention(s): Treated rats underwent 14-day oral treatment with three doses of CEE: 0.1 mg/kg/day, 0.5 mg/kg/day, and 2 mg/kg/day., Main Outcome Measure(s): Cerebral and peripheral beta-endorphin and allopregnanolone levels., Result(s): Beta-endorphin levels were lower in aged vs. cycling and ovx control rats. In brain and serum allopregnanolone levels were lower in aged vs. cycling control rats, whereas in the adrenals they were higher in aged vs. cycling animals. In the hypothalamus and anterior pituitary allopregnanolone levels were lower in ovx vs. aged animals. In both ovx and aged animals, CEE treatment reverted the effects of ovariectomy and aging, in a dose-dependent manner., Conclusion(s): Aging is associated with a decrease in cerebral and peripheral beta-endorphin and allopregnanolone. In hypoestrogenic rats, CEE treatment restores allopregnanolone and beta-endorphin content; this indicates a role for these compounds as neuroendocrine mediators of the effects of estrogens.

Several studies have been performed during recent years to investigate the existence of a possible endocrine cause for premenstrual syndrome (PMS); the results reported are often discordant. Great interest has been raised around allopregnanolone, which could be involved in the determination of mood disorders reported by PMS patients. During the luteal phase, lower levels of this hormone have been detected in PMS patients. The aim of our study was to evaluate estradiol, progesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), androstenedione, total and free testosterone, cortisol, pregnenolone and allopregnanolone levels in 20 patients suffering from PMS and to compare them with those found in 20 fertile healthy women in the follicular and the luteal phases. Adrenocorticotropic hormone (ACTH) tests after dexamethasone suppression were performed in 10 patients of each group during the follicular and the luteal phases. In the PMS group, significantly lower allopregnolone levels were found in the luteal phase, while progesterone was lower in the PMS group in both phases. In the PMS group, higher free testosterone levels were found during the luteal phase and higher DHEA levels in both the follicular and the luteal phases. The present data confirm reduced allopregnanolone levels in the luteal phase in PMS patients, together with higher levels of DHEA and free testosterone. It is possible to conclude that, in addition to the previously described reduced luteal secretion of allopregnanolone, the adrenal gland production of this steroid in PMS sufferers is also impaired in the luteal phase. Considering the specific actions of these hormones on the control of mood and behavior, this specific hormonal milieu may contribute to the cyclic occurrence of anxiety, aggressiveness and irritability reported by PMS patients.

In the human central nervous system, progesterone is rapidly metabolised to 5 alpha-dihydroprogesterone which subsequently is further reduced to allopregnanolone (AP). These conversions are catalysed by 5 alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD). Although different isoforms of both enzymes have been identified in the brain, our knowledge of their expression in the human brain remains limited. The aim of the present study was to investigate the mRNA expression of 5 alpha-reductase 1 as well as 3 alpha-HSD 1, 2, 3 and 20 alpha-HSD in brain tissue from patients with pharmacoresistant temporal lobe epilepsy (TLE). Specimens were derived from either the hippocampus or the temporal lobe cortex and from the tumor-free approach corridor tissue of patients with brain tumors. Quantification of different mRNAs was achieved by real time PCR. In addition, we provide data on simultaneous evaluation of serum AP concentrations. We could demonstrate that 3 alpha-HSD 1 was not expressed in the hippocampus and temporal lobe of patients with TLE. In the hippocampus and temporal lobe, the expression levels of 3 alpha-HSD 2 were about 20% of that in liver tissue, those of 3 alpha-HSD 3 about 7% and those of 20 alpha-HSD about 2%, respectively. In patients with TLE, expression of 3 alpha-HSD 2 was significantly higher in the hippocampus than in temporal lobe cortex tissue (P<0.006). AP concentrations did not correlate significantly with the mRNA expression levels of 5 alpha-reductase 1, 3 alpha-HSD 2 and 3 and 20 alpha-HSD in any of the patient groups under investigation. In conclusion, the present study demonstrates mRNA expression of 5 alpha-reductase 1 and 3 alpha-HSD 2 and 3 and 20 alpha-HSD in the hippocampus and temporal lobe of epileptic patients. These findings provide further molecular biological evidence for the formation and metabolism of neuroactive steroids in the human brain.

Objectives: Several natural or synthetic estrogenic molecules are commonly used in oral hormone replacement therapy for the relief of menopausal complaints and for the primary prevention of cardiovascular disease and osteoporosis. Little information is available concerning the comparative efficacy of different compounds on neuroendocrine function. The opioid peptide beta-endorphin (beta-EP), and the neurosteroid allopregnanolone are considered markers of neuroendocrine function and their synthesis and action is regulated by gonadal steroids. The present study aimed to investigate the effects of a 2-week oral treatment with estradiol valerate (EV), estrone sulphate (ES), or conjugated equine estrogen (CEE) on central and peripheral beta-EP and allopregnanolone levels in ovariectomized (OVX) female rats., Methods: Twelve groups of Wistar OVX rats received oral EV (0.05, 0.1, 0.5 and 1 mg/Kg/day) or ES (0.1, 0.5, 1 and 2 mg/Kg/day), or CEE (0.1, 0.5, 1 and 2 mg/Kg/day) for 14 days. One group of fertile and one group of OVX rats were used as controls. beta-EP content was assessed in hypothalamus, hippocampus, anterior and neurointermediate pituitary, and plasma, while allopregnanolone content was assessed in hypothalamus, hippocampus, anterior pituitary, adrenals and serum., Results: Ovariectomy induced a significant decrease in beta-EP and allopregnanolone content in hypothalamus, hippocampus, pituitary, and serum, while it increased allopregnanolone content in the adrenals. In OVX rats, the administration of each molecule reversed the ovariectomy-induced beta-EP and allopregnanolone changes in a dose-dependent fashion, therefore completely restoring their concentration. At higher doses, the estrogenic compounds induced significantly higher levels of allopregnanolone and beta-EP than in fertile rats. CEE induced higher allopregnanolone levels in hypothalamus, anterior pituitary and serum than the other estrogenic molecules, and in the hippocampus with respect to EV alone. CEE produced higher beta-EP levels in the hippocampus and hypothalamus with respect to EV and ES., Conclusion: In the examined tissue and serum estrogens restore the ovariectomy induced changes in allopregnanolone and beta-EP content in a dose-dependent manner; the magnitude of these effects is not uniform and it is related to the different tissues and the employed compounds.

Objective: To investigate whether allopregnanolone, a neuroactive steroid involved in modulating behavioural and neuroendocrine functions, shows episodic secretion in eumenorrheic women, during the follicular and luteal phases of the menstrual cycle, and in women with stress-induced amenorrhea., Patients: Six eumenorrheic women and 14 women with hypothalamic amenorrhea were enrolled for the present study., Methods: All subjects underwent hormonal evaluation in baseline conditions and a pulsatility study to determine LH, cortisol and allopregnanolone episodic release. Eumenorrheic subjects were investigated twice, in the follicular phase (days 3-7) and in the luteal phase (days 18-22) of the menstrual cycle. LH, FSH, prolactin, estradiol, phosphate, DHEA, allopregnanolone and cortisol levels were evaluated in each case., Results: In healthy women, serum gonadotropin and gonadal steroid levels were significantly lower (P<0.01 and P<0.05 respectively) than those in amenorrheic subjects. Allopregnanolone was higher in amenorrheic subjects and during the luteal phase, compared with the follicular phase, of eumenorrheic subjects (P<0.01). Pulse analysis revealed a significant episodic discharge of allopregnanolone in all subjects (follicular phase 6.5+/-0.3 peaks/6 h and luteal phase 5.5+/-0.4 peaks/6 h, hypothalamic amenorrhea 7.0+/-0.7 peaks/6 h) with higher pulse amplitude in amenorrheic subjects and during the luteal phase compared with the follicular phase of the eumenorrheic subjects (P<0.05). Moreover, the specific concordance index demonstrated that allopregnanolone is coupled with LH only during the luteal phase of the cycle and with cortisol during both phases. Allopregnanolone-cortisol coupling was also observed in amenorrheic subjects., Conclusions: Allopregnanolone is secreted episodically. Both the ovary and adrenal glands release this steroid hormone and it shows temporal coupling with LH only during the luteal phase, with cortisol during both the studied phases of the menstrual cycle in eumenorrheic women and again with cortisol in hypothalamic amenorrheic patients.

Raloxifene is a selective estrogen modulator able to exert an estrogen-like action on some target tissues and a specific antiestrogenic action on the uterus and breast. In ovariectomized rats, it has been shown to stimulate the beta-endorphin and allopregnanolone concentrations of the anterior and neurointermediate pituitary lobes, the hypothalamus and the hippocampus. The present study aimed to evaluate, in 12 healthy postmenopausal women, the effect of 60 mg/day raloxifene hydrochloride administration for 6 months on plasma beta-endorphin and allopregnanolone levels, and on the dynamic changes of both beta-endorphin and allopregnanolone secretion after the administration of: (1) clonidine, an alpha 2-presynaptic adrenergic agonist; (2) naloxone, an opioid receptor antagonist; and (3) fluoxetine, a serotonin selective reuptake inhibitor. The administration of raloxifene significantly increased both circulating beta-endorphin and allopregnanolone concentrations, at both the third and sixth months of treatment (p < 0.01). Clonidine, fluoxetine and naloxone administration before therapy was not able to stimulate the release of beta-endorphin, but the response was completely restored after raloxifene administration. Before therapy, clonidine and naloxone tests were accompanied by a significant rise in allopregnanolone secretion; the same changes were observed after raloxifene administration, but with significantly higher allopregnanolone concentrations at each time considered. While the fluoxetine test before therapy failed to increase the release of allopregnanolone, the same test after 6 months of raloxifene administration was characterized by a significant release of allopregnanolone at 60 and 90 minutes. The present data indicate that raloxifene has an estrogen-like effect on neuroendocrine pathways in postmenopausal women.

Purpose: Several lines of evidence indicate that there exists a relation between ovarian hormones and epilepsy. Estrogens decrease seizure threshold and increase brain excitability, whereas progesterone has an inhibitory effect and reduces epileptiform activity. Recently considerable interest has turned to neuroactive steroids, a group of progesterone metabolites, as endogenous modulators of excitability of the central nervous system (CNS). Their ability to alter neuronal firing rapidly occurs through interaction with gamma-aminobutyric acid (GABA) A receptor complex. In a previous experience, serum allopregnanolone (3alpha-OH-5alpha-pregnan-20-one) levels were measured in 15 women with partial epilepsy in the intercritical phase, and no significant differences were found between patients and control subjects., Methods: To find out if there are changes in serum allopregnanolone levels after epileptic seizure, blood samples were drawn immediately, 15 min, and 6 h after a seizure in seven fertile females with partial epilepsy., Results: The most interesting finding is that allopregnanolone increases in serum during the first 15 min after partial seizures (p < 0.05) and decreases after 6 h., Conclusions: These data are consistent with a role for allopregnanolone in the control of neuronal excitability and seizures.

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 17beta-estradiol (17beta-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 17beta-E2 (0.1 or 1 microg/day) or LY-117018 (25, 250, and 1,250 microg/day), or 17beta-E2 1 microg/day plus LY-117018: 25, 250, and 1,250 microg/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 17beta-E2 or LY- 117018 restored ovariectomy-induced allopregnanolone changes. The administration of LY-117018 in addition to 17beta-E2 to OVX animals suppressed the increase in allopregnanolone levels determined by 17beta-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 17beta-E2, both in OVX animals treated with 17beta-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., (Copyright 2000 S. Karger AG, Basel.)

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 Tanner's 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 Tanner' s 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.

The endocrine characteristics of patients with premature ovarian failure (POF) have not been fully elucidated. The aim of the present study was to evaluate whether steroidogenic activity in women with POF is different with respect to fertile and postmenopausal subjects. In particular, circulating levels of allopregnanolone, a neuroactive steroid involved in modulation of reproductive function in rats, have been evaluated and correlated with serum levels of delta 4 precursor (dehydroepiandrosterone sulfate (DHEAS)), delta 5 intermediates (androstenedione, 17-hydroxyprogesterone (17-OHP), progesterone) and final products (estradiol and testosterone) of androgens. Levels of luteinizing hormone (LH), follicle stimulating hormone (FSH) and sex hormone binding globulin (SHBG) were also determined. In all cases specific radioimmunological assays were used. Women with POF showed statistically significantly lower concentrations of 17-OHP, androstenedione and testosterone when compared to fertile controls, while no differences were found between women with POF and postmenopausal women. Serum DHEAS levels were similar in POF patients and in fertile controls and higher with respect to postmenopausal women. Serum allopregnanolone levels were significantly higher in women with POF than in postmenopausal and in fertile women. A significant inverse correlation between allopregnanolone levels and menopausal age in patients with POF was observed while no significant correlation was found between allopregnanolone and progesterone, androstenedione, 17-OHP and testosterone levels. In conclusion, allopregnanolone is scarcely influenced by the reduction of ovarian and adrenal activity observed in POF.

Allopregnanolone is a neuroactive steroid involved in modulating behavioral functions, stress, and neuroendocrine axes in rats. Changes in plasma allopregnanolone levels throughout the menstrual cycle have been reported in healthy women, but there exists no information on the possible gender or age-related changes or on the source(s) of circulating allopregnanolone. The aim of the present study was to assess serum allopregnanolone concentrations according to gender, menstrual cycle, age, and menopause in normal men and women; serum progesterone (P) and dehydroepiandrosterone (DHEA) levels were evaluated in the same specimens. In addition, the possible source of circulating allopregnanolone in fertile women was investigated by using stimulatory and inhibitory endocrine tests acting on the ovary and/or adrenal cortex. The present study included 189 fertile women, 112 postmenopausal women, and 46 men. Serum steroid levels were determined after extraction, using specific RIAs. Allopregnanolone levels in fertile women in the follicular phase were similar to those in age-matched men; no significant difference was found between fertile women in the follicular phase and postmenopausal women. The highest levels were found in fertile women during the luteal phase (P < 0.01). An age-related decrease was observed in men (P < 0.01), but not in women. P and DHEA levels were significantly higher in women than in men and were higher in fertile women than in postmenopausal women (P < 0.01). Both P and DHEA showed an age-related decrease in men and women (P < 0.01). Serum allopregnanolone and P, but not DHEA, significantly increased in response to a GnRH test, whereas corticotropin-releasing factor and ACTH tests elicited a significant increase in allopregnanolone, P, and DHEA levels (P < 0.01). The suppression of adrenal steroidogenesis by dexamethasone markedly reduced both allopregnanolone and DHEA serum levels (P < 0.01). In conclusion, the present study demonstrated that although men show an age-related decrease, serum allopregnanolone levels in women do not change with age and correlate with P levels during the menstrual cycle and in response to endocrine tests. Ovary and adrenal cortex may be major sources of circulating allopregnanolone in fertile women.

Objective: Allopregnanolone is a potent neuroactive steroid hormone produced in the brain and in peripheral endocrine glands. The present study investigated possible age-related variations in allopregnanolone content in brain areas, endocrine glands and serum of male rats., Design: Wistar male rats were categorized into 5 groups (6 rats in each) according to age: 6, 12, 16, 18 and 20 months respectively., Methods: Allopregnanolone content in acidic homogenates of brain cortex, hypothalamus, pituitary, adrenals and gonads was measured by a specific radioimmunoassay. Serum allopregnanolone, corticosterone and testosterone were also assayed by radioimmunoassay., Results: Brain cortex allopregnanolone content decreased significantly with age, while hypothalamic allopregnanolone content remained constant until 18 months and increased significantly at 20 months. Pituitary content showed a significant age-related reduction. Adrenal allopregnanolone content remained constant until 18 months, and was significantly higher at 20 months. Testis and serum allopregnanolone contents showed significant age-related increases. Serum testosterone levels showed an age-related decrease, while no age-related variation in serum corticosterone was found., Conclusions: The present study showed a significant impact of aging on allopregnanolone contents in brain, endocrine glands and serum, showing an age-related decrease in brain cortex and pituitary, and an age-related increase in testes, adrenals and serum.