Matteo Pieri

Effect of different hormonal replacement therapies on circulating allopregnanolone and dehydroepiandrosterone levels in postmenopausal women

The effects of hormone replacement therapy (HRT) on the central nervous system in postmenopausal women might be mediated by changes in neurosteroid synthesis and/or release. The aim of this study was to evaluate the impact of HRT on the levels of allopregnanolone ,a sedative anxiolytic GABAA agonist steroid ,and dehydroepiandrosterone (DHEA) ,a GABAA antagonist steroid. We evaluated allopregnanolone and DHEA circulating levels after 1 ,3 ,6 ,9 and 12 months of HRT with ten different estrogen or estrogen-progestin molecules ,regimens and routes of administration in 186 postmenopausal women. Cortisol ,luteinizing hormone ,follicle stimulating hormone ,estradiol and progesterone levels were also evaluated. Allopregnanolone levels significantly increased during follow-up with all HRT preparations. The addition of progestin molecules (except for 19-nor derivatives) to transdermal estradiol administration alone determined a higher increase in allopregnanolone levels. Transdermal HRT showed a significantly higher percentage change in allopregnanolone levels compared with oral HRT. DHEA levels showed a progressive decline starting from the 3-month follow-up ,without significant differences between the transdermal and oral groups ,as well as among the ten groups ,independently of the presence and type of progestin molecule used. In conclusion ,HRT strongly modifies circulating neurosteroid levels in postmenopausal women.

CNS: Sex Steroids and SERMs

Abstract: The central nervous system (CNS) is one of the main target tissues for sex steroid hormones, which act both through genomic mechanisms, modulating synthesis, release, and metabolism of many neuropeptides and neurotransmitters, and through nongenomic mechanisms, influencing electrical excitability, synaptic function, and morphological features. The identification of the brain as a de novo source of neurosteroids modulating cerebral function, suggests that the modifications in mood and cognitive performances occurring in postmenopausal women could also be related to a modification in the levels of neurosteroids, particularly allopregnanolone and DHEA, GABA‐A agonist, and antagonist, respectively. The selective estrogen receptor modulators (SERMs) are compounds that activate the estrogen receptors with different estrogenic and antiestrogenic tissue‐specific effects. In addition to the effects of the classic steroid hormones on the CNS, the study of selective estrogen receptor modulators impact on the neuroendocrine system has recently provided encouraging results, indicating that raloxifene analog LY 117018 and the new generation SERM EM‐652 have an estrogen‐like action on β‐endorphin and on allopregnanolone in ovariectomized rats, while they exert an anti‐estrogenic effect in fertile rats and in ovariectomized rats treated with estrogens. In addition, raloxifene administration in postmenopausal women plays an estrogen‐like effect on circulating β‐EP and allopregnanolone levels, and it restores the response of β‐EP and allopregnanolone to neuroendocrine tests. In conclusion, the positive effects of HRT on mood and cognition in postmenopausal women occur via the modulation of neuroendocrine pathways and probably also of neurosteroidogenesis. The effects of raloxifene on mood and cognition encourage the efforts in the research of an ideal estrogen replacement therapy, showing all the positive effects of estrogens and fewer side effects.

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.

Conjugated equine estrogens, estrone sulphate and estradiol valerate oral administration in ovariectomized rats: effects on central and peripheral allopregnanolone and β-endorphin

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.

Tibolone, transdermal estradiol or oral estrogen-progestin therapies: Effects on circulating allopregnanolone, cortisol and dehydroepiandrosterone levels

The aim of the present study was to evaluate, in healthy postmenopausal women, the impact of tibolone (2.5 mg), transdermal estradiol (50 μg) (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.

Long-term low-dose oral administration of dehydroepiandrosterone modulates adrenal response to adrenocorticotropic hormone in early and late postmenopausal women.

Objective. The aging process is associated with a decline in the circulating Δ5-androgen dehydroepiandrosterone (DHEA) and its sulfate ester, dehydroepiandrosterone sulfate (DHEAS). The present study aimed to evaluate the effects of a long-term (12 months) oral DHEA administration (25 mg/day) on adrenal function, before and after 3, 6 and 12 months of treatment. Method. Postmenopausal women belonging to two age groups, 50–55 years (n = 10) and 60–65 years (n = 10), were studied. Adrenal function was assessed in basal conditions, after suppression with dexamethasone (DXM) and following a stimulation test with adrenocorticotropic hormone (ACTH) (10 μg bolus). Serum levels of DHEA, DHEAS, androstenedione (Δ4-A), allopregnanolone, 17-hydroxyprogesterone (17-OHP) and cortisol were measured and the effects of DHEA supplementation on specific adrenal enzymatic pathways were evaluated by calculating precursor/product ratios (17-OHP/cortisol, 17-OHP/Δ4-A, DHEA/Δ4-A and DHEA/DHEAS). Results. DHEA supplementation annulled the age-related differences in DHEA and DHEAS levels and induced a marked increase in all steroids, except for cortisol, after 3–6 months of treatment. Serum cortisol levels decreased from the 3rd month, both in younger and older subjects. DHEA supplementation did not affect DXM-induced suppression of adrenal steroidogenesis. During the treatment period all adrenal androgens and progestins showed a significant increase in their response to ACTH, while the cortisol response decreased significantly. The results suggest a significant DHEA-induced change in adrenal enzymatic activities, as also evidenced by the change in precursor/product ratios during therapy. Conclusion. Chronic DHEA administration is capable of modifying circulating levels of androgens and progestins in both early and late postmenopausal women by modulating the age-related changes in adrenal function.

Drospirenone increases central and peripheral β-endorphin in ovariectomized female rats

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 &bgr;-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 &bgr;-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. &bgr;-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 &bgr;-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 &bgr;-endorphin and allopregnanolone levels in all brain areas analyzed and in plasma/serum. Drospirenone treatment significantly increased &bgr;-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 &bgr;-endorphin or allopregnanolone levels. Drospirenone showed an additive and synergistic effect with estradiol in the neurointermediate lobe on &bgr;-endorphin synthesis. Conclusions: Drospirenone significantly increases central and circulating &bgr;-endorphin levels and does not seem to interfere with allopregnanolone production.

Effects of the new generation selective estrogen receptor modulator EM-652 and oral administration of estradiol valerate on circulating, brain, and adrenal β-endorphin and allopregnanolone levels in intact fertile and ovariectomized rats

OBJECTIVE To investigate the effects of oral estradiol valerate (EV); EM-652, a new-generation selective estrogen receptor modulator; and both agents on central and peripheral beta-endorphin (beta-EP) and allopregnanolone levels in fertile and ovariectomized rats. DESIGN Prospective study. SETTING Animal laboratory in an academic research environment. ANIMALS Thirteen groups of eight Wistar female rats received oral EV (0.01 or 0.05 mg/kg of body weight daily), EM-652 (0.1, 1, or 5 mg/kg daily), or EV (0.05 mg/kg daily) and EM-652 (0.1, 1, or 5 mg/kg/daily) for 14 days. INTERVENTION(S) beta-Endorphin levels content in the hypothalamus, hippocampus, anterior and neurointermediate pituitary, and plasma were measured. Allopregnanolone levels in the hypothalamus, hippocampus, anterior pituitary, adrenal glands, and serum were measured. MAIN OUTCOME MEASURE(S) beta-Endorphin and allopregnanolone levels. RESULT(S) In ovariectomized rats, administration of EV or EM-652 reverses changes in beta-EP and allopregnanolone levels induced by ovariectomy. Administration of EM-652 plus EV prevents the increase in beta-EP and allopregnanolone levels induced by EV in the hippocampus, hypothalamus, and pituitary but not in the adrenal glands and serum. CONCLUSIONS In ovariectomized rats, EM-652 has an estrogen-like action that becomes antiestrogenic in the presence of EV administration. In fertile animals, EM-652 exerts estrogen-like or slight antiestrogenic effects.

5-Androgens and postmenopause: effects of 6 months DHEA supplementation in postmenopausal women

Abstract Background: The adrenal production of dehydroepiandrosterone (DHEA) and its sulphate ester, dehydroepiandrosterone sulphate (DHEAS), declines linearly with ageing. Starting from the evidence that DHEA and DHEAS (DHEA(S)) administration may alleviate some of the problems related to ageing, the present study aimed to investigate the effects of a 6-month DHEA supplementation. Methods: Early and late postmenopausal women, with different body mass index (BMI), were treated with oral DHEA (50 mg/daily) for 6 months. Circulating steroids, sex-hormone binding globulin (SHBG), β-endorphin (β-EP) and gonadotropins were evaluated monthly. The adrenal gland response to dexamethasone (dxm) suppression and ACTH stimulation were evaluated before and after 3 and 6 months of therapy. Postmenopausal symptoms were evaluated with a Kupperman questionnaire. Results: DHEA, DHEAS, androstenedione (A), testosterone (T), dihydrotestosterone (DHT), estrone (E1), estradiol (E2), 17OH-progesterone (17-OHP), allopregnanolone (allop) and β-endorphin levels increased during the 6 months of the treatment. Progesterone (P) and 17-OH pregnenolone (17-OH pregn) remained constant. Sex hormone-binding globulin levels significantly decreased only in overweight, late postmenopausal women, while cortisol and gonadotropins levels progressively deceased in all groups. ACTH stimulus induced a significant response in all parameters and, after the treatment, it prompted a greater response in Δ5 and Δ4 androgens, progesterone and 17-OHP, while cortisol responded less, both in younger and in older normal-weight subjects. Conclusions: The present findings confirm that DHEA supplementation produces physiological and supraphysiological modifications in steroid milieu and adrenal function.