Oral dehydroepiandrosterone restores ß-endorphin response to OGTT in early and late postmenopause.

ß-endorphin is a neuropeptide involved in several brain functions: its plasma levels are higher in obese women and its release increases after oral glucose tolerance test (OGTT) in normal or obese women. The study included 46 healthy women and evaluated the effect of oral dehydroepiandrosterone [DHEA] (50 mg/day) in early postmenopausal women (50-55 years) both of normal weight (group A, n = 12, BMI = 22.1 ± 0.5) and overweight (group B, n = 12, BMI = 28.2 ± 0.5), and late postmenopausal women (60-65 years) both normal weight (group C, n = 11, BMI = 22.5 ± 0.6) and overweight (group D, n = 11, BMI = 27.9 ± 0.4) undergone OGTT, in order to investigate if DHEA could restore/modify the control of insulin and glucose secretion and ß-endorphin release in response to glucose load. The area under the curve (AUC) of OGTT evaluated plasma levels of different molecules. DHEA, DHEAS, and ß-endorphin plasma levels were lower in baseline conditions in older women than younger women. Considering the AUC of ß-endorphin response to OGTT, all groups showed a progressive significant increase after 3 and also after 6 months of treatment in comparison to baseline and 3 months of treatment.

Soy isoflavones, inulin, calcium, and vitamin D3 in post-menopausal hot flushes: an observational study.

PURPOSE OF INVESTIGATION: To evaluate the effect of soy isoflavones and inulin (SII) on hot flushes (HF) and quality of life in a clinical setting, the authors conducted an observational study. MATERIALS AND METHODS: The authors performed an observational, prospective, multicentric study on women in peri-/post-menopause treated or untreated with a product present on the Italian market, consisting in a mixture of calcium (500 mg), vitamin D3 (300 IU), inulin (3 g) and soy isoflavones (40 mg). RESULTS: A total of 135 patients, 75 (55.6%) in the SII group and 60 (44.4%) in the untreated group entered the study. After three months, the mean number of HF declined of 2.8 (SD 3.7) in the SII group and 0.0 in the untreated one. The corresponding values after six months were -3.7 (SD 2.7) in the SII group and -0.9 (SD 5.3) in the control group (p = 0.02). CONCLUSION: This observational trial suggests a possible beneficial effect of a dietary soy supplement containing 40 mg of isoflavone/day plus inulin in the management of menopausal symptoms such as hot flashes.

Effect of 1-year, low-dose DHEA therapy on climacteric symptoms and female sexuality.

BACKGROUND: Sexual desire is affected by endocrine and psychosocial factors. Menopausal hormonal changes are relevant to the causes of sexual dysfunction during reproductive aging. AIM: To evaluate the effects of different types of hormonal replacement therapy (HRT) on sexual function, frequency of sexual intercourse, and quality of relationship in early postmenopausal women. We recruited 48 healthy postmenopausal women aged 50-60 years (mean age 54.5 ± 3.3 years). Women with climacteric symptoms were uniformly randomized into three groups receiving either dehydroepiandrosterone (DHEA 10 mg) daily, or daily oral estradiol (1 mg) plus dihydrogesterone (5 mg), or daily oral tibolone (2.5 mg) for 12 months. Women who refused hormonal therapy were treated with oral vitamin D (400 IU). Efficacy was evaluated using the McCoy Female Sexuality Questionnaire before treatment and after 12 months. We evaluated the hormonal profile before treatment and after 3, 6 and 12 months. RESULTS: The groups receiving DHEA or HRT reported a significant improvement in sexual function compared to baseline (p < 0.001 and p < 0.01, respectively) using the McCoy total score. The quality of relationship was similar at baseline and after 3, 6 and 12 months of treatment. There were significant increases in the numbers of episodes of sexual intercourse in the previous 4 weeks in women treated with DHEA, HRT and tibolone in comparison with the baseline value (p < 0.01, p < 0.05, p < 0.01, respectively). No changes in the McCoy score occurred in women receiving vitamin D. CONCLUSIONS: Daily oral DHEA therapy at the dose of 10 mg, HRT and tibolone all provided a significant improvement in comparison with vitamin D in sexual function and in frequency of sexual intercourse in early postmenopausal women.

Human umbilical vein endothelial cells: a new source and potential target for corticotropin-releasing factor.

Corticotropin-releasing factor (CRF) plays a key role in the modulation of fetal-placental unit function during human pregnancy. CRF has a potent vasoactive action on fetal-placental circulation. As products secreted from endothelial cells affect vascular wall reactivity, we investigated whether cultured human umbilical vein endothelial cells (HUVEC) may represent a source and a target for CRF. With RT-PCR we showed that HUVEC express CRF and CRF receptor type 2 messenger ribonucleic acids. Cultured HUVEC also released CRF peptide in a time-dependent way, and the CRF release was differently regulated by various molecules. Dexamethasone decreased CRF release, whereas progesterone and 17beta-estradiol markedly increased it. Forskolin and PGF2alpha were potent stimulators of CRF release from HUVEC. Among the peptides, CRF secretion was stimulated by interleukin-1beta and by endothelin-1. Our study shows for the first time that HUVEC express CRF messenger ribonucleic acid and peptide as well as the CRF R2 gene, and that CRF release is differentially regulated by several distinct molecules. We here propose that CRF has a role in the regulation of the fetal-placental circulation.

Hypothalamic amenorrhea with normal body weight: ACTH, allopregnanolone and cortisol responses to corticotropin-releasing hormone test.

OBJECTIVE: Hypothalamic amenorrhea (HA) is a functional disorder caused by disturbances in gonadotropin-releasing hormone (GnRH) pulsatility. The mechanism by which stress alters GnRH release is not well known. Recently, the role of corticotropin-releasing hormone (CRH) and neurosteroids in the pathophysiology of HA has been considered. The aim of the present study was to explore further the role of the hypothalamic-pituitary-adrenal axis in HA. DESIGN: We included 8 patients (aged 23.16+/-1.72 years) suffering from hypothalamic stress-related amenorrhea with normal body weight and 8 age-matched healthy controls in the follicular phase of the menstrual cycle. METHODS: We measured basal serum levels of FSH, LH, and estradiol and evaluated ACTH, allopregnanolone and cortisol responses to CRH test in both HA patients and healthy women. RESULTS: Serum basal levels of FSH, LH, and estradiol as well as basal levels of allopregnanolone were significantly lower in HA patients than in controls (P<0.001) while basal ACTH and cortisol levels were significantly higher in amenorrheic patients with respect to controls (P<0.001). The response (area under the curve) of ACTH, allopregnanolone and cortisol to CRH was significantly lower in amenorrheic women compared with controls (P<0.001, P<0.05, P<0.05 respectively). CONCLUSIONS: In conclusion, women with HA, despite the high ACTH and cortisol levels and, therefore, hypothalamus-pituitary-adrenal axis hyperactivity, are characterized by low allopregnanolone basal levels, deriving from an impairment of both adrenal and ovarian synthesis. The blunted ACTH, allopregnanolone and cortisol responses to CRH indicate that, in hypothalamic amenorrhea, there is a reduced sensitivity and expression of CRH receptor. These results open new perspectives on the role of neurosteroids in the pathogenesis of hypothalamic amenorrhea.

Antagonism by pivagabine of stress-induced changes in GABAA receptor function and corticotropin-releasing factor concentrations in rat brain.

Pivagabine [4-(2.2-dimethyl-l-oxopropylamino) butanoic acid] (PVG) is a hydrophobic 4-aminobutyric acid derivative with neuromodulatory activity. The effects of subchronic treatment with PVG on stress-induced changes both on brain concentrations of corticotropin-releasing factor (CRF) and neurosteroids and on the function of the gamma-aminobutyric acid type A (GABAA) receptor complex were investigated in male rats. Subchronic treatment with PVG (100-200 mg/kg, i.p.) resulted in a dose-dependent inhibition of the foot shock-induced increase in the binding of t-[35S]butylbicyclophosphorothionate to unwashed membranes prepared from the cerebral cortex of rats killed immediately after stress; PVG treatment alone had no effect on this parameter. This antagonistic action of PVG was also shown in adrenalectomized-orchietomized rats. Foot-shock stress decreased by 74% and increased by 125% the CRF concentration in the hypothalamus and cerebral cortex, respectively. PVG prevented these effects of stress on CRF concentration in both brain regions; this drug per se reduced hypothalamic CRF concentration by 52% but had no effect in the cortex. Moreover, intracerebroventricular injection of CRF, like stress, induced a dose-dependent increase of [35S]TBPS binding to cerebral cortical membranes: an effect not prevented by subchronic treatment of PVG. Finally, PVG did not antagonize the stress-induced increases in the concentrations of neuroactive steroids in brain or plasma. These results suggest that the marked antistress action of PVG is mediated by antagonizing the effects of stress on GABA(A) receptor function and CRF concentrations in the brain, but not by altering the stress-induced increase in neurosteroid concentrations.

CNS: sex steroids and SERMs.

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 beta-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 beta-EP and allopregnanolone levels, and it restores the response of beta-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.

Oral dehydroepiandrosterone supplementation modulates spontaneous and growth hormone-releasing hormone-induced growth hormone and insulin-like growth factor-1 secretion in early and late postmenopausal women.

OBJECTIVE: To evaluate the effects of dehydroepiandrosterone (DHEA) supplementation on the growth hormone-releasing hormone-growth hormone (GHRH-GH) axis in lean and obese postmenopausal women. DESIGN: Prospective study. SETTING: Postmenopausal women in a clinical research environment. PATIENT(S): Thirty-one postmenopausal women were divided in two groups by age (50 to 55 and 60 to 65 years). Within each group, lean and obese patients were considered. INTERVENTION(S): All patients underwent hormonal evaluations before and at the third and sixth month of therapy (50 mg of DHEA orally each day) and a GHRH test (1 microg/kg) before and at the sixth month of treatment. Ultrasound and bone mass density (BMD) examinations were performed before and after the sixth month of therapy. MAIN OUTCOME MEASURE(S): Plasma dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), E1, E2, androstenedione (A), testosterone (T), osteocalcin, GH, insulin-like growth factor 1 (IGF-1) concentrations. RESULT(S): The levels of all of the steroids that derived from DHEA metabolism (E1, E2, A, T, DHEAS) and osteocalcin were increased in plasma under DHEA supplementation. The supplementation protocol also increased the levels of GH and IGF-1. However, GHRH-induced GH and IGF-1 responses were not modified by DHEA supplementation. CONCLUSION(S): Administration of DHEA significantly affects several endocrine parameters in early and late postmenopausal women independently from body mass index. Our data support the hypothesis that DHEA treatment acts similarly to estrogen-progestin replacement therapy on the GHRH-GH-IGF-1 axis. This suggests that DHEA is more than a more than a simple "diet supplement" or "antiaging product"; rather it should be considered an effective hormonal replacement treatment.

Lack of effect of psychosocial stress on maternal corticotropin-releasing factor and catecholamine levels at 28 weeks' gestation.

OBJECTIVE: Corticotropin-releasing factor (CRF) and catecholamines are among the major hormones activated during the adaptive response to stressful stimuli. In pregnant women, serum CRF and catecholamines levels increase during labor and preterm delivery. The aim of the present study was to evaluate whether psychosocial stress measures are correlated with serum CRF or urinary catecholamine [ie, epinephrine, norepinephrine (NE), dopamine (DA)] levels in healthy midtrimester pregnant women. METHODS: A large group of white pregnant women (n = 382) participated in the present study. The Work Conditions Questionnaire and the Psychiatric Epidemiology Research Interview were administered to measure job stress and general life stress, respectively. Urine and blood specimens were collected at 28 weeks of gestation at the time of psychosocial evaluation. Epinephrine, NE, and DA were quantified in the urine by a highly sensitive method based on an amperometric detector. Serum CRF and cortisol levels were measured in blood specimens by using specific radioimmunoassays. RESULTS: Serum CRF and cortisol levels did not vary between patients with high and low scores on psychological tests, and no correlation was found between CRF and cortisol levels. One job stress measure, low job latitude, was significantly associated with a mild increase in NE and DA levels in the afternoon and night (P < .05, analysis of variance). Serum cortisol levels were inversely correlated with NE in the morning (r = -0.447; P =.002) and night segments (r = -0.391; P = .007) and with DA in the night period (r = -0.367; P = .013). CONCLUSION: The absence of a significant relationship between CRF/cortisol and psychosocial stress measures in pregnant women suggests that the hypothalamic-pituitary-adrenal response to psychosocial stress may be masked at midtrimester by the constantly high levels of placental CRF, whose control is beyond the influence of environmental stressors.

Neuroendocrine effect of a short-term treatment with DHEA in postmenopausal women.

OBJECTIVES: A progressive decline of plasma dehydroepiandrosterone (DHEA) levels occurs in women during aging related to the reduction of adrenocortical secretion. A specific action of DHEA on the central nervous system (CNS) is suggested by the improvement of psychological and physical well-being in postmenopausal women after DHEA supplementation. The aim of the present study was to investigate the neuroendocrine effects of short-term DHEA supplementation in postmenopausal women, evaluating changes of plasma beta-endorphin (beta-EP) and growth hormone (GH) before and after oral DHEA (100 mg/day) for 7 days in postmenopausal women (n = 6). METHODS: Before and after 7 days of DHEA supplementation, postmenopausal women underwent a neuroendocrine test with clonidine, an alpha 2 presinaptic agonist for adrenergic system (1.25 mg i.v.). Basal plasma DHEA, androstenedione (A), testosterone (T), estrone (E1) and estradiol (E2) levels were evaluated before and after treatment, while plasma beta-EP and GH levels were measured before and 15, 30, 45, 60 and 90 min after clonidine injection. RESULTS: Basal plasma beta-EP and GH levels did not show a significant difference before and after short-term DHEA administration, while circulating A, T, E1 and E2 significantly increased after treatment. The clonidine test induced a significant increase of plasma beta-EP levels in women after receiving DHEA supplementation but not before; conversely, plasma GM levels increased both before and after treatment. CONCLUSIONS: The present study indicates that short-term DHEA supplementation in postmenopausal women is able to restore the impaired response of pituitary beta-EP to clonidine, an alpha 2 presinaptic agonist. According to these data it is possible to hypothesize that DHEA could play a role in the psychological and physical well-being of postmenopausal women acting via a restoration of neuroendocrine control of antero-pituitary beta-EP secretion.

Neuroendocrine effects of different estradiol-progestin regimens in postmenopausal women.

OBJECTIVE: New regimens and routes of administration of hormonal replacement therapy (HRT) in climateric women are becoming available. Since there is no information on the neuroendocrine effects of sequential combined treatment with 17 beta-estradiol and a progestin, the present study evaluated the neuroendocrine, clinical vasomotor and psychological changes before and after different sequential combined HRT regimens (17 beta-estradiol plus nomegestrol acetate, or cyproterone acetate, or vaginal progesterone). Vasomotor and behavioral effects were evaluated by using the Kupperman score, while changes in plasma endorphin (beta-END) levels were used as marker of neuroendocrine effects. METHODS: Postmenopausal women (n = 30) were randomly divided into three groups (ten women for each group); all women received continuous 17 beta-estradiol (50 mg, transdermal) and each group was sequentially treated with different progestins for 12 days/month: group A, cyproterone acetate (5 mg p.o.); group B, nomegestrol acetate (5 mg p.o.); and group C, progesterone (100 mg, vaginal cream). A group of healthy fertile women (n = 8) served as control. Before and after 6 months of HRT, postmenopausal women underwent an evaluation of subjective Kupperman score and two neuroendocrine tests: (a) naloxone (4 mg i.v.) and (b) clonidine (1.25 mg i.v.). Plasma beta-END levels were measured before and at 15, 30, 45, 60 and 90 min after drug injection. Control women were studied by administering the two neuroendocrine tests only once. RESULTS: Postmenopausal women before HRT showed a pathological Kupperman and no changes of plasma beta-END levels in response to the clonidine and naloxone tests score. On the contrary the increase was significant in healthy women. In each of the three groups of treated women both naloxone and clonidine tests induced a significant increase in plasma beta-END levels (P < 0.01). After 6 months of HRT, an improvement of vasomotor and psychological symptoms was shown by a decrease of Kupperman score. CONCLUSIONS: The present study indicates that sequential treatment with transdermal 17 beta-estradiol and progestin, no matter which progestin was used, restores the beta-END release, improves vasomotor and psychological symptoms.

Contraception as prevention and therapy: sex steroids and the brain.

The brain is one of the specific target tissues for sex steroid hormones. Estrogens, progestins and androgens are able to induce several effects in brain areas of the central nervous system (CNS), through the binding with specific receptors. Specific receptors for gonadal steroids have been identified in the amygdala, hippocampus, basal forebrain cortex, cerebellum, locus ceruleus, midbrain rafe nuclei, glial cells, pituitary gland, hypothalamus and central gray matter. At the hypothalamic level, the principal target for sex steroids is those neurons producing the pulsatile release of the gonadotropin releasing hormone (GnRH), localized in the mediobasal hypothalamus and the arcuate nucleus. The GnRH release depends on the complex and co-ordinated interrelationships among gonadal steroids, pituitary gonadotropins and neuroactive transmitters, such as the noradrenaline, dopamine, opioid peptides (beta-endorphin), acetylcholine, serotonin, gamma-aminobutyrric acid, corticotropin releasing hormone and neuropeptide Y. The interplay of these control mechanisms is governed by peripheral feedback signals; as well as the input from higher brain centers they may modify the GnRH secretion. The anterior pituitary lobe is the best known target tissue for endogenous or exogenous sex steroid hormones, because it is possible to detect luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in blood, as the expression of the pituitary cells' activity. The synthesis and release of FSH and LH by the gonadotropic cells depend upon the peripheral control of gonadal hormones and the GnRH hypothalamic release. In summary, during a woman's reproductive life, the interaction between neurotransmitters, neuropeptides and gonadal hormones modulates the hypothalamo-pituitary-gonadal axis by acting selectively on the synthesis and release of GnRH and of pituitary gonadotropic hormones. The increased use of oral contraceptives in the last 30 years and, in general, of sex steroid hormone derivative therapies, has led to the study of the biochemical and metabolic properties of the different progestin molecules available in hormonal therapies by focusing attention on the interactions between estrogens and progestins in the modulation of the hypothalamo-pituitary-gonadal axis. The different kinds of estrogen and progestin molecules used in oral contraceptives inhibit the ovulatory process and may interfere with other sex steroid hormone receptors, thus exerting multiple effects in each target tissue.

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 GABA(A) agonist steroid, and dehydroepiandrosterone (DHEA), a GABA(A) 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.

Increased midtrimester amniotic fluid activin A: a risk factor for subsequent fetal death.

OBJECTIVE: The objective of this study was to determine whether concentrations of activin A and corticotropin-releasing factor in amniotic fluid can identify patients at risk of fetal death. STUDY DESIGN: A retrospective case-control study of women who have had a midtrimester amniocentesis was designed. Case subjects consisted of patients who had a spontaneous fetal death after the procedure, whereas the control group consisted of patients who had a normal pregnancy outcome after midtrimester amniocentesis. Dimeric activin A was measured by a specific 2-site enzyme immunoassay, and corticotropin-releasing factor was measured by a specific and sensitive radioimmunoassay after acidic extraction. Statistical analysis was performed with Mann-Whitney U test, Fisher's exact test, and chi2 tests and regression analysis. RESULTS: First, activin A was detectable in all amniotic fluid samples. Second, the concentration of activin A in amniotic fluid increased with advancing gestational age. Third, patients who subsequently had a fetal death had a higher median concentration of activin A than those with a normal pregnancy outcome (P <.01). Fourth, an amniotic fluid concentration of activin A greater than the 95th confidence interval for gestational age was found in 40% of patients who subsequently had a fetal death (odds ratio: 21.6; P <.005). Finally, the median concentration of corticotropin-releasing factor in amniotic fluid was not different in case subjects and control subjects. CONCLUSIONS: An elevated concentration of activin A in amniotic fluid identifies women at risk of fetal death.

Endocrine, neuroendocrine and behavioral effects of oral dehydroepiandrosterone sulfate supplementation in postmenopausal women.

Aging in women and men is characterized by a progressive decline of circulating dehydroepiandrosterone (DHEA) levels and its sulfate ester (DHEAS). The improvement of wellbeing described in postmenopausal women treated with DHEA suggests that this steroid may exert specific actions on the central nervous system (CNS). The postmenopausal period is associated with several neuroendocrine modifications. The decrease of circulating levels of beta-endorphin is considered a hormonal marker of those changes. The aim of the present study was to investigate neuroendocrine and behavioral effects of three months of DHEAS supplementation in postmenopausal women. Postmenopausal women (n = 22) were divided in three groups: the first group was treated with oral DHEAS (n = 8) (50 mg/day), the second treated with the same dose of oral DHEAS + transdermal estradiol (n = 8) (DHEAS) 50 mg/day, estradiol 50 micrograms/patch) and the third with transdermal estradiol alone (n = 6) (50 micrograms/day). Before and after 1, 2 and 3 months of therapy, the following circulating steroid and protein hormone levels were evaluated: DHEA, DHEAS, androstenedione, testosterone, estrone, estradiol, 17-hydroxyprogesterone, sex hormone-binding globulin (SHBG), follicle-stimulating hormone (FSH), luteinizing hormone (LH), beta-endorphin, growth hormone (GH) and cortisol, and a Kupperman score was performed. Before and after treatments, plasma beta-endorphin levels were evaluated in response to three neuroendocrine tests: (a) clonidine, an alpha 2-presynaptic adrenergic agonist (1.25 mg i.v.) (b) naloxone, an opioid receptor antagonist (4 mg i.v.) and (c) fluoxetine, a serotonin selective reuptake inhibitor (30 mg p.o.). In both groups of women treated with DHEAS, mean basal serum DHEA, DHEAS, androstenedione, and testosterone levels significantly increased after treatment, while no changes were shown in the group receiving estradiol alone. Serum estradiol, estrone, GH and plasma beta-endorphin levels significantly increased progressively for the three months of treatment, with higher levels for estrone and estradiol in subjects receiving estradiol alone or plus DHEAS. Serum SHBG, cortisol, and 17-hydroxyprogesterone did not show significant variations under any treatment. Serum LH and FSH levels showed a significant decrease in groups treated with estradiol alone or plus DHEAS at the second and third months. The Kupperman score showed that all treatments were associated with similar and progressive improvement. Before therapy clonidine, naloxone and fluoxetine stimuli failed to modify circulating beta-endorphin levels. After each of the treatments, the beta-endorphin response was completely restored and was similar, independent of the kind of therapy. Restoration of the beta-endorphin response to specific stimuli suggests that DHEAS and/or its active metabolites modulates the neuroendocrine control of pituitary beta-endorphin secretion, which may support the therapeutic efficacy of the DHEAS on behavioral symptoms.

Effects of sex steroid hormones on the neuroendocrine system.

Estrogen and progesterone are the most important ovarian steroid hormones regulating female fertility. They have a profound effect on the central nervous system. Target functions of sex steroids in the brain are: pituitary and hypothalamic hormone release, thermoregulatory and cardiocirculatory activities and behavior and mood changes. Furthermore, several studies have shown a correlation between brain neurotransmitters, neuropeptides and sex steroid hormones: they influence synthesis and release of norepinephrine, dopamine, serotonin, gonadotropin releasing hormone, beta-endorphin, corticotropin releasing factor and prolactin. Thus, oral hormone contraceptives inhibit the ovulatory process by blocking the activity of the hypothalamus-pituitary-gonadal axis. This inhibitory effect seems to be due to the action of both estrogens and progestins.

Corticotropin-releasing factor-binding protein: origins and possible functions.

Corticotropin-releasing hormone-binding protein (CRFBP) is a 37-kD protein of 322 amino acids, containing one putative N-glycosylation site and 11 cysteines, 10 of which remain in the mature molecule (298 amino acids) and result essential for the action. CRFBP protein gene has been cloned and mapped to the distal region of chromosome 13 and loci5q in the mouse and human genomes. CRFBP is the only example of a neuropeptide-binding protein. It is produced in human and rat brain, and in human liver and placenta. In brain, the central distribution of CRFBP shares some regional overlap with CRF receptor-bindings sites. Additionally, in hypothalamic and limbic structures, CRFBP has been identified in association with CRF-expressing cell groups. CRFBP has been also demonstrated in the human placenta and related membranes. Indeed, amniotic epithelium, chorionic cytotrophoblast, and maternal decidua also show intense positive CRFBP mRNA signals. Circulating CRFBP levels in healthy nonpregnant individuals show the same range values as in maternal plasma collected during the first and second trimesters of pregnancy. A rise in CRFBP levels at 30-35 weeks of pregnancy with a dramatic decrease at 38-40 weeks have been shown. At postpartum, CRFBP levels in maternal plasma reach the nonpregnant concentrations. Recombinant and native CRFBP neutralize the ACTH-releasing activity of human CRF in cultured pituitary or placental cells and, additionally, may block the activity of CRF on human pregnant endometrium prostaglandin release and on human myometrium contractility in vitro. These findings suggest that CRFBP may play a role in modulating the functions of CRF in human pregnancy.

Effects of hormonal replacement therapy on plasma sex hormone-binding globulin, androgen and insulin-like growth factor-1 levels in postmenopausal women.

Plasma sex hormone-binding globulin (SHBG) levels are important in the regulation of plasma free and albumin-bound androgens and estrogens. In postmenopausal women associated to the decrease of estrogen production, a decrease of plasma SHBG levels occurs. Hormone replacement therapy (HRT) in postmenopausal women modulates plasma SHBG levels, in relationship with the different regimens and routes of administration. The present study aimed to compare the effect of different HRT on plasma SHBG levels in relationship with the changes of plasma androgen [dehydroepiandrosterone sulphate (DHEAS), testosterone (T), androstenedione (A)] and insulin-like growth factor-1 (IGF-1) levels. In a retrospective study 443 postmenopausal women were studied and divided into 2 groups. The group 1 (n = 170) was subdivided in 4 groups of women as follows: A) treated with transdermal 17-beta estradiol + medroxyprogesterone acetate, B) treated with oral conjugated estrogens, C) treated with sequential HRT (estradiol valerate (EV) + norgestrel), and D) treated with a combined HRT (micronized estradiol (E2) + noretisterone acetate). Women of group 2 (n = 273) did not receive HRT and served as controls. All groups of women treated with different HRT showed plasma estradiol levels significantly higher than controls (p < 0.01), showing the highest values in women treated with oral HRT. Plasma SHBG levels were not significantly different between patients treated with transdermal 17-beta estradiol + medroxyprogesterone acetate and controls. On the other hand, all the groups of patients treated with oral conjugated estrogen with or without progestagens showed plasma SHBG levels significantly higher than controls (p < 0.01). Plasma SHBG levels were higher in the group treated with estrogen alone than in groups of women treated with sequential or combined HRT. Plasma DHEAS, T and A levels in patients treated with different HRT regimens were in the same range of levels as control women. Plasma IGF-1 levels were not significantly affected by the various HRT regimens and remained in the same range as controls. In conclusion, plasma SHBG levels increase following oral HRT while are not affected by transdermal HRT. Plasma IGF-1 and androgen levels are not influenced from oral or transdermal HRT.

High levels of serum allopregnanolone in women with premature ovarian failure.

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.

Raloxifene analog LY 117018 effects on central and peripheral beta-endorphin.

Raloxifene is a selective estrogen receptor modulator with a benzothiophene structure, that exerts an estrogen-like action on some target tissues and an anti-estrogenic action on the uterus and breasts. A limited number of data are available on the effect of raloxifene on neuroendocrine function. Since beta-endorphin (beta-EP) is considered a marker of neuroendocrine function, the aim of the present study was to evaluate the effects of a 14 day treatment with a raloxifene analog, LY 117018, on beta-EP content in the hypothalamus, hippocampus, anterior and neuro-intermediate pituitary lobe, and in the plasma of fertile and ovariectomized (ovx) rats. The effect of LY 117018 in ovx rats was compared to that of 17 beta-estradiol. beta-EP contents were measured by a specific radioimmunoassay. While ovariectomy determined a significant decrease in beta-EP levels in the anterior and neurointermediate pituitary lobe and plasma (p < 0.01), no changes of beta-EP content in the hypothalamus and hippocampus were found. The administration of 17 beta-estradiol or LY 117018 in ovx rats significantly increased beta-EP concentration in the anterior and neurointermediate pituitary lobe, in the hypothalamus and plasma (p < 0.01), though they did not significantly modify hippocampal beta-EP content. When LY 117018 was administered together with 17 beta-estradiol in ovx animals, a clear anti-estrogenic effect in all organs and in plasma was observed, resulting in significantly lower beta-EP content with respect to the group treated with 17 beta-estradiol alone (p < 0.01). The chronic administration of LY 117018 in fertile rats significantly decreased beta-EP content in the anterior pituitary, hippocampus and plasma (p < 0.01), while it increased beta-EP hypothalamic content and did not change beta-EP content in the neurointermediate lobe. In conclusion, raloxifene analog LY 117018 has an estrogen-like action on neuroendocrine opiatergic pathways when administered alone in ovx rats, while it exerts an anti-estrogen effect in fertile or in ovx rats treated with 17 beta-estradiol.