Progesterone and progestins: effects on brain, allopregnanolone and beta-endorphin

Differences in Pubertal Curve Progression among Females with Adolescent Idiopathic Scoliosis Using Pregnenolone Therapy: A Retrospective Case-Controlled Series

Background: Differences in hormone metabolism have been observed in children with adolescent idiopathic scoliosis. These differences have been offered as underlying reasons for rapid curve progression during puberty. This study retrospectively compared two groups of females with a history of adolescent idiopathic scoliosis. They were seen for initial presentation prior to menarche, or within 2 months after menarche, and they were followed up 1 year after first menarche. Methods: All patients in both groups underwent baseline salivary hormone testing to identify any hormone imbalances. The control group was composed of females with curves between 10 and 25 degrees and maintained an observation-only management strategy. The treatment group showed baseline curve measurements ranging from 10 to 23 degrees, and additionally took pregnenolone daily for 12 months. Results: At one-year follow-up, the treatment group showed curve measurements ranging from 13 to 24 degrees, while the control group ranged from 16 to 29 degrees (p < 0.05). Conclusions: The study showed that adolescent females taking pregnenolone daily for low progesterone had reduced scoliosis curve progression over 1 year compared to controls.

Sex steroids and the female brain across the lifespan: insights into risk of depression and Alzheimer's disease

Despite widespread sex differences in prevalence and presentation of numerous illnesses affecting the human brain, there has been little focus on the effect of endocrine ageing. Most preclinical studies have focused on males only, and clinical studies often analyse data by covarying for sex, ignoring relevant differences between the sexes. This sex- (and gender)-neutral approach is biased and contributes to the absence of targeted treatments and services for all sexes (and genders). Female health has been historically understudied, with grave consequences for their wellbeing and health equity. In this Review, we spotlight female brain health across the lifespan by informing on the role of sex steroids, particularly oestradiol, on the female brain and on risk for diseases more prevalent in females, such as depression and Alzheimer's disease.

Deleterious Interaction between the Neurosteroid (3α,5α)3-Hydroxypregnan-20-One (3α,5α-THP) and the Mu-Opioid System Activation during Forced Swim Stress in Rats

The neurosteroid 3α,5α-THP is a potent GABAA receptor-positive modulator and its regulatory action on the HPA axis stress response has been reported in numerous preclinical and clinical studies. We previously demonstrated that 3α,5α-THP down-regulation of HPA axis activity during stress is sex-, brain region- and stressor-dependent. In this study, we observed a deleterious submersion behavior in response to 3α,5α-THP (15 mg/kg) during forced swim stress (FSS) that led us to investigate how 3α,5α-THP might affect behavioral coping strategies engaged in by the animal. Given the well-established involvement of the opioid system in HPA axis activation and its interaction with GABAergic neurosteroids, we explored the synergic effects of 3α,5α-THP/opiate system activation in this behavior. Serum β-endorphin (β-EP) was elevated by FSS and enhanced by 3α,5α-THP + FSS. Hypothalamic Mu-opiate receptors (MOP) were increased in female rats by 3α,5α-THP + FSS. Pretreatment with the MOP antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP; 2 mg/kg, IP) reversed submersion behavior in males. Moreover, in both males and females, CTAP pretreatment decreased immobility episodes while increasing immobility duration but did not alter swimming duration. This interaction between 3α,5α-THP and the opioid system in the context of FSS might be important in the development of treatment for neuropsychiatric disorders involving HPA axis activation.

Validation of an ELISA kit to measure allopregnanolone in human and equine hair

In humans, allopregnanolone plays important roles in a number of different neurodegenerative disorders, and it has been proposed for use in some therapies. Horses are commonly used as animal models for human neurodegenerative diseases, mental and behavioral disorders, and neuropsychiatric disorders, and there is interest in using hair as a biological sample to study hormones in these conditions. We validated the use of a commercial ELISA kit (DetectX allopregnanolone kit; Arbor Assays), which was designed for serum, plasma, feces, urine, and tissue samples, to assess allopregnanolone in hair samples from 30 humans and 63 horses. The ELISA kit had good precision (intra- and inter-assay CVs: 6.4% and 11.0% for equine hair; 7.3% and 11.0% for human hair, respectively), sensitivity (50.4 pg/mL for both equine and human hair), and accuracy (parallelism and recovery tests) in determining allopregnanolone concentrations in hair from both species. The allopregnanolone concentrations in human hair were 7.3-79.1 pg/mg; the concentrations were 286 ± 141 pg/mg (x̄ ± SD) in mares on the day of parturition and 16.9 ± 5.5 pg/mg in nonpregnant mares. The DetectX ELISA kit offered a simple and accessible analysis of allopregnanolone in human and equine hair samples.

Hormonal contraception and cognition: Considering the influence of endogenous ovarian hormones and genes for clinical translation

Despite the well-known influence of ovarian hormones on the brain and widespread use of hormonal contraception (HC) since the 1960s, our knowledge of HC's cognitive effects remains limited. To date, the cognitive findings have been inconsistent. In order to establish what might make HC studies more consistent, we surveyed the literature on HCs and cognition to determine whether studies considered HC formulation, phase, pharmacokinetics, duration, and gene interactions, and assessed whether oversight of these factors might contribute to variable findings. We found that synthetic HC hormones exert dose-dependent effects, the day of oral contraceptive (Pill) ingestion is critical for understanding cognitive changes, and gene-cognition relationships differ in women taking the Pill likely due to suppressed endogenous hormones. When these factors were overlooked, results were not consistent. We close with recommendations for research more likely to yield consistent findings and be therefore, translatable.

Sex Hormones, Sleep, and Memory: Interrelationships Across the Adult Female Lifespan

As the population of older adults grows, so will the prevalence of aging-related conditions, including memory impairments and sleep disturbances, both of which are more common among women. Compared to older men, older women are up to twice as likely to experience sleep disturbances and are at a higher risk of cognitive decline and Alzheimer's disease and related dementias (ADRD). These sex differences may be attributed in part to fluctuations in levels of female sex hormones (i.e., estrogen and progesterone) that occur across the adult female lifespan. Though women tend to experience the most significant sleep and memory problems during the peri-menopausal period, changes in memory and sleep have also been observed across the menstrual cycle and during pregnancy. Here, we review current knowledge on the interrelationships among female sex hormones, sleep, and memory across the female lifespan, propose possible mediating and moderating mechanisms linking these variables and describe implications for ADRD risk in later life.

Hormonal contraceptives as disruptors of competitive behavior: Theoretical framing and review

Emerging evidence suggests that hormonal contraceptives (HCs) impact psychological outcomes through alterations in neurophysiology. In this review, we first introduce a theoretical framework for HCs as disruptors of steroid hormone modulation of socially competitive attitudes and behaviors. Then, we comprehensively examine prior research comparing HC users and non-users in outcomes related to competition for reproductive, social, and financial resources. Synthesis of 46 studies (n = 16,290) led to several key conclusions: HC users do not show the same menstrual cycle-related fluctuations in self-perceived attractiveness and some intrasexual competition seen in naturally-cycling women and, further, may show relatively reduced status- or achievement-oriented competitive motivation. However, there a lack of consistent or compelling evidence that HC users and non-users differ in competitive behavior or attitudes for mates or financial resources. These conclusions are tentative given the notable methodological limitations of the studies reviewed. Implications and recommendations for future research are discussed.

The influence of hormonal contraception on depression and female sexuality: a narrative review of the literature

OBJECTIVE

Over the past decades, an increasing number of women have been using hormonal contraception. The potential role of sex hormones in regulating vegetative, psychophysiological, and cognitive functions has been highlighted in several studies, and there is a need to further understand the impact of hormonal contraception on women's quality of life, especially as regards psychological health and sexuality.

METHODS

We conducted a narrative review aimed at clarifying the mechanisms involved in the interaction between sex hormones and the brain, also focusing on the association between hormonal contraception and mood and sexual function.

RESULTS

Our findings clarified that hormonal contraception may be associated with depressive symptoms, especially among adolescents, and with sexual dysfunction. However, the evidence included in this review was conflicting and did not support the hypothesis that hormonal contraception directly causes depressive symptoms, major depressive disorder, or sexual dysfunction.

CONCLUSIONS

The optimal hormonal contraception should be identified in the context of shared decision making, considering the preferences and needs of each woman, as well as her physical and psychosexual conditions.

Superior mesenteric ganglion neural modulation of ovarian angiogenesis, apoptosis and proliferation by the neuroactive steroid allopregnanolone

Allopregnanolone (ALLO), a potent neuroactive steroid, is synthesized and active in the peripheral nervous system. Previous studies have shown that ALLO participates in the central regulation of reproduction with effects on ovarian physiology, although there is little evidence for its ability to modulate peripheral tissues. The present study aimed to determine whether ALLO, administered to an ex vivo system that comprises the superior mesenteric ganglion (SMG), the ovarian nervous plexus (ONP) and the ovary (O), or to the denervated ovary (DO), was able to modify ovarian apoptosis, proliferation and angiogenesis. For this purpose, the SMG-ONP-O system and DO were incubated during 120 min at 37°C, in the presence of two ALLO doses (0.06 µm and 6 µm). The intrinsic and extrinsic pathways of apoptosis were analyzed. Incubation of the SMG-ONP-O system with ALLO 0.06 µm led to an increase in the BAX/BCL-2 ratio and a reduction of FAS-L mRNA levels. ALLO 6 µm induced a decrease of FAS-L levels. Incubation of DO with ALLO 0.06 µm reduced FAS-L, whereas ALLO 6 µm significantly increased it. Cyclin D1 mRNA was measured to evaluate proliferation. Treatment with ALLO 6 µm increased proliferation in both SMG-ONP-O and DO. ALLO 0.06 µm produced an increase of Cyclin D1 in DO only. Administration of either ALLO dose led to a higher ovarian expression of vascular endothelial growth factor in the SMG-ONP-O system, but a lower one in the DO system. ALLO 6 µm induced ovarian sensitization to GABA by increasing GABA_A receptor expression. In conclusion, ALLO participates in the peripheral neural modulation of ovarian physiology. It can also interact directly with the ovarian tissue, modulating key mechanisms involved in normal and pathological processes in a dose-dependent manner.

Altered Steroidome in Women with Gestational Diabetes Mellitus: Focus on Neuroactive and Immunomodulatory Steroids from the 24th Week of Pregnancy to Labor

Gestational diabetes mellitus (GDM) is a complication in pregnancy, but studies focused on the steroidome in patients with GDM are not available in the public domain. This article evaluates the steroidome in GDM+ and GDM- women and its changes from 24 weeks (± of gestation) to labor. The study included GDM+ (n = 44) and GDM- women (n = 33), in weeks 24-28, 30-36 of gestation and at labor and mixed umbilical blood after delivery. Steroidomic data (101 steroids quantified by GC-MS/MS) support the concept that the increasing diabetogenic effects with the approaching term are associated with mounting progesterone levels. The GDM+ group showed lower levels of testosterone (due to reduced AKR1C3 activity), estradiol (due to a shift from the HSD17B1 towards HSD17B2 activity), 7-oxygenated androgens (competing with cortisone for HSD11B1 and shifting the balance from diabetogenic cortisol towards the inactive cortisone), reduced activities of SRD5As, and CYP17A1 in the hydroxylase but higher CYP17A1 activity in the lyase step. With the approaching term, the authors found rising activities of CYP3A7, AKR1C1, CYP17A1 in its hydroxylase step, but a decline in its lyase step, rising conjugation of neuroinhibitory and pregnancy-stabilizing steroids and weakening AKR1D1 activity.

Double-Blind, Placebo-Controlled Trial of Cyproterone Acetate to Prevent Flare-Up Effect on Dogs Implanted With Deslorelin

Deslorelin slow-released implants are registered in Europe for the reversible suppression of fertility in male dogs. After administration, a time-limited increase in sex hormones concentration and related behavioral problems may be observed. The aim of this work was to assess whether cyproterone acetate, a synthetic progestogen, can prevent this flare-up effect. Eighteen privately-owned entire male dogs were enrolled in this double-blind, placebo-controlled, randomized clinical trial. All subjects received a 4.7 mg deslorelin implant by SC route and 1-3 capsules containing either cyproterone acetate 2 mg/kg (N = 9) or a placebo (N = 9), by oral route BID for 14 days, depending on the dog's weight. The dogs were followed for 28 days. An increase in the blood testosterone concentration was observed in respectively 9/9 and 7/9 dogs of the control and cyproterone groups (p = 0.47). However, a worsening of the sex hormone related problems (i.e., urinary marking, mounting, aggressiveness toward other dogs and/or escape) was only observed in the placebo group, in 56 or 66% of the dogs as measured by respectively the veterinarian and the owners. Our study suggests that cyproterone acetate is effective and safe to supress the deslorelin induced behavioral flare-up effect, but not the rise in testosterone.

Brain intracrinology of allopregnanolone during pregnancy and hormonal contraception

Allopregnanolone (ALLO) has a crucial role in brain development and remodeling. Reproductive transitions associated with endocrine changes affect synthesis and activity of ALLO with behavioral/affective consequences. Pregnancy is characterized by an increased synthesis of progesterone/ALLO by the placenta, maternal and fetal brains. This suggests the critical role of these steroids in maternal brain adaptation during pregnancy and the development of the fetal brain. ALLO is brain protective during complications of pregnancy, such as preterm delivery or intrauterine growth restriction (IUGR), reducing the impact of hypoxia, and excitotoxic brain damage. Negative behavioral consequences of altered progesterone/ALLO maternal brain adaptation have been also hypothesized in the post-partum and targeting ALLO is a promising treatment. Hormonal contraception may alter ALLO action, although the effects are mostly related to a specific class of progestins. Understanding the interactions between ALLO and the endocrine environment is crucial for more effective and tailored hormonal treatments.

Impact of sex and reproductive status on memory circuitry structure and function in early midlife using structural covariance analysis

Research on age-related memory alterations traditionally targets individuals aged ≥65 years. However, recent studies emphasize the importance of early aging processes. We therefore aimed to characterize variation in brain gray matter structure in early midlife as a function of sex and menopausal status. Subjects included 94 women (33 premenopausal, 29 perimenopausal, and 32 postmenopausal) and 99 demographically comparable men from the New England Family Study. Subjects were scanned with a high-resolution T1 sequence on a 3 T whole body scanner. Sex and reproductive-dependent structural differences were evaluated using Box's M test and analysis of covariances (ANCOVAs) for gray matter volumes. Brain regions of interest included dorsolateral prefrontal cortex (DLPFC), inferior parietal lobule (iPAR), anterior cingulate cortex (ACC), hippocampus (HIPP), and parahippocampus. While we observed expected significant sex differences in volume of hippocampus with women of all groups having higher volumes than men relative to cerebrum size, we also found significant differences in the covariance matrices of perimenopausal women compared with postmenopausal women. Associations between ACC and HIPP/iPAR/DLPFC were higher in postmenopausal women and correlated with better memory performance. Findings in this study underscore the importance of sex and reproductive status in early midlife for understanding memory function with aging.

Early phosphoproteomic changes for adverse outcome pathway development in the fathead minnow (Pimephales promelas) brain

Adverse outcome pathways (AOPs) are conceptual frameworks that organize and link contaminant-induced mechanistic molecular changes to adverse biological responses at the individual and population level. AOPs leverage molecular and high content mechanistic information for regulatory decision-making, but most current AOPs for hormonally active agents (HAAs) focus on nuclear receptor-mediated effects only despite the overwhelming evidence that HAAs also activate membrane receptors. Activation of membrane receptors triggers non-genomic signaling cascades often transduced by protein phosphorylation leading to phenotypic changes. We utilized label-free LC-MS/MS to identify proteins differentially phosphorylated in the brain of fathead minnows (Pimephales promelas) aqueously exposed for 30 minutes to two HAAs, 17α-ethinylestradiol (EE2), a strong estrogenic substance, and levonorgestrel (LNG), a progestin, both components of the birth control pill. EE2 promoted differential phosphorylation of proteins involved in neuronal processes such as nervous system development, synaptic transmission, and neuroprotection, while LNG induced differential phosphorylation of proteins involved in axon cargo transport and calcium ion homeostasis. EE2 and LNG caused similar enrichment of synaptic plasticity and neurogenesis. This study is the first to identify molecular changes in vivo in fish after short-term exposure and highlights transduction of rapid signaling mechanisms as targets of HAAs, in addition to nuclear receptor-mediated pathways.

The fetal brain: role of progesterone and allopregnanolone

Progesterone and allopregnanolone have crucial and different roles in brain development, function and recovery after injury. Pregnancy is characterized by an increased synthesis of progesterone and its neuro-active metabolites by the placenta, maternal and fetal brain. This supports the critical role of these steroids in maternal brain adaptation during pregnancy and development of the fetal brain. Moreover, allopregnanolone may play a brain-protective role during complications of pregnancy, complications of pregnancy, such as preterm delivery or intrauterine growth restriction (IUGR), by reducing the impact of hypoxia and excitotoxic brain damage or impairment myelination. Behavioral consequences of altered progesterone/allopregnanolone fetal brain programming have also been hypothesized, although further evidence is needed. New potential applications of allopregnanolone as a treatment strategy have also been proposed, addressing unmet clinical needs in perinatal care.

Effects of Sex Steroids in the Human Brain

Sex steroids are thought to play a critical developmental role in shaping both cortical and subcortical structures in the human brain. Periods of profound changes in sex steroids invariably coincide with the onset of sex differences in mental health vulnerability, highlighting the importance of sex steroids in determining sexual differentiation of the brain. Yet, most of the evidence for the central effects of sex steroids relies on non-human studies, as several challenges have limited our understanding of these effects in humans: the lack of systematic assessment of the human sex steroid metabolome, the different developmental trajectories of specific sex steroids, the impact of genetic variation and epigenetic changes, and the plethora of interactions between sex steroids, sex chromosomes, neurotransmitters, and other hormonal systems. Here we review how multimodal strategies may be employed to bridge the gap between the basic and clinical understanding of sex steroid-related changes in the human brain.

Estrogen- and progesterone-mediated structural neuroplasticity in women: evidence from neuroimaging

There is substantial evidence that the ovarian sex hormones, estrogen and progesterone, which vary considerably over the course of the human female lifetime, contribute to changes in brain structure and function. This structured, quantitative literature reviews aims to summarize neuroimaging literature addressing physiological variation in brain macro- and microstructure across an array of hormonal transitions including the menstrual cycle, use of hormonal contraceptives, pregnancy, and menopause. Twenty-five studies reporting structural neuroimaging of women, addressing variation across hormonal states, were identified from a structured search of PUBMED and were systematically reviewed. Although the studies are heterogenous with regard to methodology, overall the results point to overlapping areas of hormone related effects on brain structure particularly affecting the structures of the limbic system. These findings are in keeping with functional data that point to a role for estrogen and progesterone in mediating emotional processing.

Ethinyl estradiol and levonorgestrel alter cognition and anxiety in rats concurrent with a decrease in tyrosine hydroxylase expression in the locus coeruleus and brain-derived neurotrophic factor expression in the hippocampus

In the United States, more than ten million women use contraceptive hormones. Ethinyl estradiol and levonorgestrel have been mainstay contraceptive hormones for the last four decades. Surprisingly, there is scant information regarding their action on the central nervous system and behavior. Intact female rats received three weeks of subcutaneous ethinyl estradiol (10 or 30μg/rat/day), levonorgestrel (20 or 60μg/rat/day), a combination of both (10/20μg/rat/day and 30/60μg/rat/day), or vehicle. Subsequently, the rats were tested in three versions of the novel object recognition test to assess learning and memory, and a battery of tests for anxiety-like behavior. Serum estradiol and ovarian weights were measured. All treatment groups exhibited low endogenous 17β-estradiol levels at the time of testing. Dose-dependent effects of drug treatment manifested in both cognitive and anxiety tests. All low dose drugs decreased anxiety-like behavior and impaired performance on novel object recognition. In contrast, the high dose ethinyl estradiol increased anxiety-like behavior and improved performance in cognitive testing. In the cell molecular analyses, low doses of all drugs induced a decrease in tyrosine hydroxylase mRNA and protein in the locus coeruleus. At the same time, low doses of ethinyl estradiol and ethinyl estradiol/levonorgestrel increased galanin protein in this structure. Consistent with the findings above, the low dose treatments of ethinyl estradiol and combination ethinyl estradiol/levonorgestrel reduced brain-derived neurotrophic factor mRNA in the hippocampus. These effects of ethinyl estradiol 10μg alone and in combination with levonorgestrel 20μg suggest a diminution of norepinephrine input into the hippocampus resulting in a decline in learning and memory.

Estrogens and progestins: molecular effects on brain cells

Sex steroids are known to regulate brain function and their role is so important that several diseases are strictly correlated with the onset of menopause when estrogen-progesterone deficiency makes neural cells much more vulnerable to toxic stimuli. Although in the past years several scientists have focused their studies on in vitro and in vivo effects of sex steroids on the brain, we are still far from complete knowledge. Indeed, contrasting results from large clinical trials have made the entire issue much more complicated. Currently we know that protective effects exerted by sex steroids depend on several factors among which the dose, the health of the cells and the type of molecule being used. In this review, we present an overview of the direct and indirect effects of estrogen and progesterone on the brain with specific focus on the molecular mechanisms by which these molecules act on neural cells.

A role for synapsin in FKBP51 modulation of stress responsiveness: Convergent evidence from animal and human studies

Both the molecular co-chaperone FKBP51 and the presynaptic vesicle protein synapsin (alternatively spliced from SYN1-3) are intensively discussed players in the still insufficiently explored pathobiology of psychiatric disorders such as major depression, schizophrenia and posttraumatic stress disorder (PTSD). To address their still unknown interaction, we compared the expression levels of synapsin and five other neurostructural and HPA axis related marker proteins in the prefrontal cortex (PFC) and the hippocampus of restrained-stressed and unstressed Fkbp5 knockout mice and corresponding wild-type littermates. In addition, we compared and correlated the gene expression levels of SYN1, SYN2 and FKBP5 in three different online datasets comprising expression data of human healthy subjects as well as of predominantly medicated patients with different psychiatric disorders. In summary, we found that Fkbp5 deletion, which we previously demonstrated to improve stress-coping behavior in mice, prevents the stress-induced decline in prefrontal cortical (pc), but not in hippocampal synapsin expression. Accordingly, pc, but not hippocampal, synapsin protein levels correlated positively with a more active mouse stress coping behavior. Searching for an underlying mechanism, we found evidence that deletion of Fkbp5 might prevent stress-induced pc synapsin loss, at least in part, through improvement of pc Akt kinase activity. These results, together with our finding that FKBP5 and SYN1 mRNA levels were regulated in opposite directions in the PFC of schizophrenic patients, who are known for exhibiting an altered stress-coping behavior, provide the first evidence of a role for pc synapsin in FKBP51 modulation of stress responsiveness. This role might extend to other tissues, as we found FKBP5 and SYN1 levels to correlate inversely not only in human PFC samples but also in other expression sites. The main limitation of this study is the small number of individuals included in the correlation analyses. Future studies will have to verify the here-postulated role of the FKBP51-Akt kinase-synapsin pathway in stress responsiveness.

Hormone testing and treatment enters pain care

A number of factors have recently coalesced to bring hormone testing and treatment to the field of pain care. Uncontrolled, severe pain as well as opioid drugs have a profound impact on the endocrine system. Because pain is a potent stressor, it initially causes pituitary, adrenal, and gonadal hormones to elevate in the serum. If severe pain goes uncontrolled for too long, however, hormone levels deplete in the serum. The finding of abnormal (too high or low) serum hormone levels serve as biomarker of endocrinopathies, which helps inform the clinician that enhanced analgesia as well as hormone replacement may be necessary. Adequate, physiologic levels of some specific hormones are necessary for optimal analgesia, neuroprotection, and neurogenesis. Although not a substitute for opioids, some hormone replacements may minimize their use. We know that the central nervous system produces a group of hormones called neurohormones whose natural function is neuroprotection and neurogenesis. Their clinical use in centralized pain states is new, and early reports indicate that they may have considerable benefit for treatment.

Ethanol self-administration and nicotine treatment increase brain levels of CYP2D in African green monkeys

BACKGROUND AND PURPOSE

CYP2D6 metabolizes many centrally acting drugs, neurotoxins and endogenous neurochemicals, and differences in brain levels of CYP2D have been associated with brain function and drug response. Alcohol consumers and smokers have higher levels of CYP2D6 in brain, but not liver, suggesting ethanol and/or nicotine may induce human brain CYP2D6. We investigated the independent and combined effects of chronic ethanol self-administration and nicotine treatment on CYP2D expression in African green monkeys.

EXPERIMENTAL APPROACH

Forty monkeys were randomized into control, ethanol-only, nicotine-only and ethanol + nicotine groups. Two groups voluntarily self-administered 10% ethanol in sucrose solution for 4 h·day(-1) , whereas two groups consumed sucrose solution on the same schedule. Two groups received daily s.c. injections of 0.5 mg·kg(-1) nicotine in saline bid, whereas two groups were injected with saline on the same schedule.

KEY RESULTS

Both nicotine and ethanol dose-dependently increased CYP2D in brain; brain mRNA was unaffected, and neither drug altered hepatic CYP2D protein or mRNA. The combination of ethanol and nicotine increased brain CYP2D protein levels to a greater extent than either drug alone (1.2-2.2-fold, P < 0.05 among the eight brain regions assessed). Immunohistochemistry revealed the induction of brain CYP2D protein within specific cell types and regions in the treatment groups.

CONCLUSIONS AND IMPLICATIONS

Ethanol and nicotine increase brain CYP2D protein levels in monkeys, in a region and treatment-specific manner, suggesting that CNS drug responses, neurodegeneration and personality may be affected among people who consume alcohol and/or nicotine.

Allopregnanolone's attenuation of the lordosis-inhibiting effects of restraint is blocked by the antiprogestin, CDB-4124

A brief restraint experience reduces lordosis behavior in ovariectomized females that have been hormonally primed with estradiol benzoate. The addition of progesterone to the priming prevents the lordosis inhibition. Based on prior studies with an inhibitor of progesterone metabolism, we have implicated the intracellular progesterone receptor, rather than progesterone metabolites, as responsible for this protection. However, the progesterone metabolite, allopregnanolone (3α-hydroxy-5α-pregnan-20-one), also prevents lordosis inhibition after restraint. In a prior study, we reported that the progestin receptor antagonist, RU486 (11β-(4-dimethylamino)phenyl-17β-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one), attenuated the effect of allopregnanolone. Because RU486 can also block the glucocorticoid receptor, in the current studies, we evaluated the effect of the progestin receptor antagonist, CDB-4124 (17α-acetoxy-21-methoxy-11β-[4-N,N-dimethyaminopheny]-19-norpregna-4,9-dione-3,20-dione), which is relatively devoid of antiglucocorticoid activity. Ovariectomized, Fischer rats were injected with 10 μg estradiol benzoate. Two days later, rats received either 60 mg/kg CDB-4124 or 20% DMSO/propylene glycol vehicle 1 h before injection with 4 mg/kg allopregnanolone. After a pretest to confirm sexual receptivity, rats were restrained for 5min and immediately tested for sexual behavior. Lordosis behavior was reduced by the restraint and attenuated by allopregnanolone. Pretreatment with CDB-4124 reduced allopregnanolone's effect. These findings support prior suggestions that allopreganolone reduces the response to restraint by mechanisms that require activation of the intracellular progesterone receptor.

Progesterone and its metabolites as therapeutic targets in psychiatric disorders

INTRODUCTION

Neurosteroids are molecules that regulate physiological functions of the CNS. There is increasing evidence suggesting that impaired neurosteroid biosynthesis has been associated with distinct psychiatric disorders. This review summarizes data from studies that have investigated the relationship between progesterone (PROG) and psychiatric disorders as well as the mechanisms potentially involved in PROG-induced neuroprotection.

AREAS COVERED

The review covers the role of PROG and its metabolites in psychiatric disorders, focusing on results from preclinical and some clinical studies that support the relationship between alterations on PROG levels and pathophysiology of psychiatric illness. We also discussed the main mechanisms underlying the neuroprotective effects of PROG metabolites.

EXPERT OPINION

Our review points out the possible relationship between PROG and its metabolites and the pathophysiology of psychiatric disorders. Furthermore, both preclinical and clinical studies show that certain treatments (antidepressants or antipsychotics) may normalize the levels of PROG, suggesting that the amelioration of psychiatric symptoms may occur due to upregulation of PROG metabolites. Therefore, these results give support to new possibilities of treatment for patients with psychiatric symptoms from anxiety- and depressive-like behaviors to aggressive behaviors.

Advances in neurosteroids: role in clinical practice

The steroidogenic endocrine glands and local synthesis both contribute to the pool of steroids present in the central nervous system and peripheral nervous system. Although the synthesis of neurosteroids in the nervous system is now well established, the spectrum of respective functions in regulating neuronal and glial functions remains to be fully elucidated. From the concept of neurosteroids derives another treatment strategy: the use of pharmaceutical agents that increase the synthesis of endogenous neurosteroids within the nervous system. This approach has so far been hampered by lack of knowledge concerning the regulation of the biosynthetic pathways of neurosteroids and their relationship with sex steroids produced by the peripheral gland or with exogenous steroids. The present review summarizes some of the available clinical and experimental findings supporting the critical role of neurosteroids during fertile life and reproductive aging and their relationship with endogenous and exogenous sex steroids. The brain metabolism of synthetic progestins and the implications of DHEA treatment in postmenopausal women will also be discussed.

Progesterone increases the activity of glutamate transporter type 3 expressed in Xenopus oocytes

Progesterone is an important sex hormone for pregnancy and also has neuroprotective and anticonvulsant effects. It is well-known that full-term parturients become more susceptible to volatile anesthetics. Glutamate transporters are important for preventing neurotoxicity and anesthetic action in the central nervous system. We investigated the effects of progesterone on the activity of glutamate transporter type 3 (EAAT3), the major neuronal EAAT. EAAT3 was expressed in Xenopus laevis oocytes by injecting its mRNA. Oocytes were incubated with diluted progesterone for 72 h. Two-electrode voltage clamping was used to measure membrane currents before, during, and after applying 30 μML-glutamate. Progesterone (1-100 nM) significantly increased EAAT3 activity in a dose-dependent manner. Our kinetic study showed that the Vmax was increased in the progesterone group compared with that in the control group (2.7 ± 0.2 vs. 3.6 ± 0.2μC for control group vs. progesterone group; n=18-23; P<0.05), however, Km was unaltered (46.7 ± 10.2μM vs. 55.9 ± 10.5μM for control group vs. progesterone group; n=18-23; P>0.05). Phorbol-12-myristate-13-acetate, a protein kinase C (PKC) activator, did not change progesterone-enhanced EAAT3 activity. Inhibitors of PKC or phosphatidylinositol 3-kinase (PI3K) abolished the progesterone-induced increases in EAAT3 activity. Our results suggest that progesterone enhances EAAT3 activity and that PKC and PI3K are involved in mediating these effects. These effects of progesterone may contribute to its anticonvulsant and anesthesia-related properties.

Progesterone facilitates exploration, affective and social behaviors among wildtype, but not 5α-reductase Type 1 mutant, mice

Progesterone (P4) facilitates exploration, anxiety and social behaviors in estrogen (E2)-primed mice. Some of these effects may be due to actions of its 5α-reduced metabolite, 5α-pregnan-3α-ol-20-one (3α,5α-THP). In order to address the role of P4 and its metabolite, 3α,5α-THP, a mouse model was utilized. We hypothesized that if P4's metabolism to 3α,5α-THP is essential to facilitate exploratory, anti-anxiety and social behaviors of mice, then wildtype, but not 5α-reductase knockout (5α-RKO), mice will have greater expression of these behaviors. Experiment 1: Mice were ovariectomized (ovx), E2-primed and administered P4 (0, 125, 250, or 500μg) subcutaneously and then tested 4h later in a battery of tasks: open field, elevated plus maze, and social interaction. Experiment 2: Ovx, E2-primed mice were administered P4 (4mg/kg), 3α,5α-THP (4mg/kg), medroxyprogesterone acetate (MPA, which does not convert to 3α,5α-THP; 4mg/kg), or vehicle subcutaneously and tested 4h later. There was a dose-dependent effect of P4 to wildtype, but not 5α-RKO, mice. Neither wildtype, nor 5α-RKO, mice had increased exploration, anti-anxiety or pro-social behavior with MPA administration. Progesterone only exerted effects on anti-anxiety behavior, and increased 3α,5α-THP in the prefrontal cortex and hippocampus, when administered to wildtype mice. 3α,5α-THP to both WT and 5α-RKO mice increased exploration, anti-anxiety and social interaction and 3α,5α-THP levels in the hippocampus and prefrontal cortex. Thus, metabolism of P4 by the 5α-reductase enzyme may be essential for enhancement of these behaviors.

An antiprogestin, CDB4124, blocks progesterone's attenuation of the negative effects of a mild stress on sexual behavior

These experiments were designed to test the hypothesis that a progesterone receptor antagonist would block progesterone's ability to reduce the negative effects of a 5 min restraint on female rat sexual behavior. Ovariectomized Fischer rats were injected with 10 μg estradiol benzoate. Two days later, rats were injected subcutaneously (sc) with the progesterone receptor antagonist, CDB4124 (17α-acetoxy-21-methoxy-11β-[4-N,N-dimethyaminopheny]-19-norpregna-4,9-dione-3,20-dione) (60 mg/kg), or vehicle (20% DMSO+propylene glycol). One hour later, rats were injected sc with 500 μg progesterone or vehicle (sesame seed oil). Rats were assigned to one of three different treatment conditions: (1) (ECV) estradiol benzoate, CDB4124, sesame seed oil vehicle, (2) (ECP) estradiol benzoate, CDB4124, progesterone, and (3) (EVP) estradiol benzoate, DMSO/propylene glycol vehicle, progesterone. That afternoon sexual behavior was examined before and after a 5 min restraint experience. Before restraint, lordosis behavior was comparable across treatment conditions but only progesterone-treated rats exhibited proceptive behavior. CDB4124 did not block progesterone's induction of proceptivity. However, after restraint, CDB4124 attenuated the positive effects of progesterone on all sexual behaviors examined. The restraint experience inhibited sexual behavior in rats treated with estradiol benzoate and CDB4124 and in rats treated with estradiol benzoate, CDB4124, and progesterone but not in rats given estradiol benzoate and progesterone without CDB4124. These findings are consistent with the hypothesis that progesterone receptors mediate progesterone's ability to reduce the negative sexual behavioral effects of a mild stressor.

RU486 blocks effects of allopregnanolone on the response to restraint stress

These experiments were designed to provide information about the potential involvement of progesterone receptors in the ability of allopregnanolone (3α-hydroxy-5α-pregnan-20-one) to reduce the lordosis-inhibiting effects of restraint stress. Ovariectomized Fischer rats were hormonally primed with 10 μg estradiol benzoate and 4 mg/kg allopregnanolone or vehicle. One hour before allopregnanolone, rats were injected with the progesterone receptor antagonist, RU486 (11β-(4-dimethylamino)phenyl-17β-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one), or vehicle. Four hours after allopregnanolone or vehicle, sexual behavior was examined before and after a 5-min restraint stress. Lordosis behavior of rats primed only with estradiol benzoate declined after the 5 min of restraint while allopregnanolone prevented this decline. RU486 attenuated the ability of allopregnanolone to prevent the restraint-induced decline in lordosis behavior. These findings are consistent with earlier suggestions that progesterone receptors are involved in allopregnanolone's ability to reduce the effects of restraint stress.

Effect of progesterone on the expression of GABA(A) receptor subunits in the prefrontal cortex of rats: implications of sex differences and brain hemisphere

Progesterone is a neuroactive hormone with non-genomic effects on GABA(A) receptors (GABA(A)R). Changes in the expression of GABA(A)R subunits are related to depressive-like behaviors in rats. Moreover, sex differences and depressive behaviors have been associated with prefrontal brain asymmetry in rodents and humans. Thus, our objective was to investigate the effect of progesterone on the GABA(A)R α1 and γ2 subunits mRNA expression in the right and left prefrontal cortex of diestrus female and male rats exposed to the forced swimming test (FST). Male and female rats (n = 8/group) were randomly selected to receive a daily dose of progesterone (0·4 mg·kg⁻¹) or vehicle, during two complete female estrous cycles (8-10 days). On the experiment day, male rats or diestrus female rats were euthanized 30 min after the FST. Our results showed that progesterone significantly increased the α1 subunit mRNA in both hemispheres of male and female rats. Moreover, there was an inverse correlation between depressive-like behaviors and GABA(A)R α1 subunit mRNA expression in the right hemisphere in female rats. Progesterone decreased the GABA(A)R γ2 mRNA expression only in the left hemisphere of male rats. Therefore, we conclude that the GABA(A) system displays an asymmetric distribution according to sex and that progesterone, at lower doses, presents an antidepressant effect after increasing the GABA(A) R α1 subunit expression in the right prefrontal cortex of female rats.

Comparison of the effects of estradiol and progesterone on serotonergic function

BACKGROUND

Ovarian hormones may contribute to the vulnerability to depression, as well as to the response to antidepressants (ADs). Previously, we reported that acute systemic treatment with estradiol or progesterone blocked the ability of the selective serotonin reuptake inhibitor, fluvoxamine, to inhibit serotonin transporter function in ovariectomized rats. In this study, behavioral consequences, as well as receptor mechanisms underlying these hormonal effects, were investigated.

METHODS

Using the forced swimming test, the acute effect of estradiol and/or progesterone on fluvoxamine's AD-like effects was investigated. Using in vivo chronoamperometry, the effect of local application of estradiol or progesterone into the hippocampus of ovariectomized rats on serotonin (5-HT) clearance, as well as on the ability of fluvoxamine to slow 5-HT clearance, were investigated.

RESULTS

The decreased immobility and increased swimming caused by fluvoxamine in the forced swimming test was blocked in rats treated with estradiol and/or progesterone. Local application of estradiol, but not progesterone, slowed 5-HT clearance and both hormones blocked the ability of fluvoxamine to slow 5-HT clearance. Use of hormone receptor agonists and antagonists, revealed that the effects of estradiol are mediated by activation of membrane, as well as nuclear estrogen receptors (ER). The AD-like effect of estradiol involved ER beta and G-protein coupled receptor 30, whereas its blockade of fluvoxamine's effects was ER alpha-mediated. The effects of progesterone occurred solely by activation of intracellular progesterone receptors.

CONCLUSIONS

Targeting of ER beta or G-protein coupled receptor 30 might reveal a strategy to permit beneficial effects of estrogen without its deleterious effect on selective serotonin reuptake inhibitor efficacy.

Sex steroids and their receptors: molecular actions on brain cells

Sex steroids exert actions of paramount importance on brain cells. They contribute to shape the central nervous system during embryo development. They modulate the formation and the turnover of the interconnections between neurons. They control the function of glial cells. And they do it through a signaling machinery that is apparently simple, but that hides a level of complexity that has been unveiled only in part. Different receptor isoforms, different interactions between receptors and co-regulators, chains of events originating at the cell membrane and leading to effects in the nucleus (or the other way around) all interact to determine selective modulations of brain cells. All these actions end up in phenomenal effects on brain function that change through adolescence, pregnancy, adulthood, up to menopause and ageing. Many of these actions are relevant for degenerative processes and research may offer soon new strategies to counteract these diseases.

Effects of oestradiol on brain lipid class and Fatty Acid composition: comparison between pregnant and ovariectomised oestradiol-treated rats

To determine the involvement of physiological doses of oestradiol on brain lipid composition, we have analysed the lipid class and fatty acid composition of phospholipids in the brain from pregnant and 17β-oestradiol-treated rats. Rats were randomly divided into three groups: ovariectomised control (OVX + VEH), ovariectomised oestradiol-treated (OVX + E(2) ) and pregnant (PREG) rats. Rats from the OVX + E(2) group were injected daily with different doses of 17β-oestradiol mimicking the plasma levels observed during pregnancy. Analyses of brain lipid class composition showed that physiological doses of oestradiol increased cholesterol levels of the OVX + E(2) group compared to the OVX + VEH group. It was also found that cholesterol levels in the PREG group were significantly lower than in the OVX + VEH and OVX + E(2) groups, indicating the involvement of gestational hormones other than oestradiol in the regulation of brain cholesterol during pregnancy. Brains from pregnant rats also exhibited reduced levels of plasmalogens and saturated fatty acids compared to the ovariectomised groups, especially in the second half of pregnancy. Interestingly, analyses of fatty acid composition of phospholipids revealed that physiological doses of oestradiol increased brain docosahexaenoic acid (DHA; 22:6 n-3) levels. Moreover, DHA levels in pregnant rats were similar to those observed in the OVX + E(2) group at all stages, suggesting that oestradiol is the main hormone in the regulation of brain DHA levels during pregnancy. Liver appears to be the major source for n-3 and n-6 long chain polyunsaturated fatty acids (LCPUFAs) DHA and arachidonic acid, which are released and transported to the maternal brain and the developing foetus under the influence of oestrogens. We also observed that the largest depots of n-3 and n-6 LCPUFA precursors (linolenic acid and linoleic acid, respectively) occur in adipose tissue triglycerides, which, in turn are significantly increased during pregnancy. Our observations are in accordance with an oestradiol-induced increased bioavailability of brain DHA in pregnant rats. We hypothesise that the reduction of maternal brain DHA observed at the end of pregnancy is a result of the very high demand DHA of foetal brain, which overcomes the maximal maternal (and likely foetal) capacity for de novo DHA synthesis in the liver and brain.

Evidences for antinociceptive effect of 17-α-hydroxyprogesterone caproate in carpal tunnel syndrome

Growing evidence of neuroprotective and analgesic effects by progesterone (PROG) has been obtained in experimental animal models of neuropathy. In this paper, we report the results of the first experimental study to test the efficacy of PROG in a human neuropathy. The effects of a local administration of 17-alpha-hydroxyprogesterone caproate (17HPC) has been studied in patients with carpal tunnel syndrome (CTS) and compared with those of a local administration of corticosteroid (CS) in a analogous CTS group. Sixteen women affected by mild CTS were selected. Clinical, electrophysiological and ultrasonographic data of the median nerve were quantified at 0 (pre-injection), 1 and 6 months after CS or 17HPC injection. One month after injection, both 17HPC and CS groups exhibited similar reduction in pain scores, whereas only the 17HPC-treated group still manifested symptoms relief 6 months after. Only in CS-treated patients, improvement of the clinical data correlated with ultrasonographic and electrophysiological changes of the median nerve. The present study indicates that intra-carpal injection with a long-acting PROG derivative is effective for relief of symptoms in CTS. This effect is apparently mediated by a mechanism distinct from that of the CS.

Progesterone effects on the discriminative stimulus, subjective and performance effects of triazolam in healthy, premenopausal women

There is accumulating evidence that sex plays a critical role in drug abuse. Female sex hormones have been shown to affect central nervous system function and modulate the effects of drugs of abuse. For example, γ-aminobutyric acid type A (GABA(A)) receptor function is positively modulated by progesterone metabolites. There is evidence from preclinical in-vitro and in-vivo studies as well as some clinical research suggesting that progesterone and its metabolites may enhance the behavioral effects of benzodiazepines, which also serve as positive modulators of GABA(A) receptors. The purpose of this experiment was to determine the independent and combined discriminative stimulus, subjective and psychomotor effects of progesterone and triazolam in healthy adult premenopausal women. Oral micronized progesterone (100 mg), triazolam (0.06, 0.12 and 0.25 mg/70 kg) and placebo were administered to healthy, premenopausal women (n=9) under conditions of low circulating sex hormones. Triazolam alone functioned as a discriminative stimulus and produced prototypical sedative-like effects (e.g., performance impairment, enhanced reports of sedative effects). Progesterone alone produced sedative-like effects on several subjective and performance measures, and the dose combination effects of progesterone and triazolam on several subjective measures of drug effect were similar to the summation of the two drug effects in isolation. Progesterone did not substitute for or modify the discriminative stimulus effects of triazolam. These results suggest that the parent hormone, progesterone, and triazolam have discordant neuropharmacological mechanisms of action. Additional research is necessary to determine the degree to which neurosteroids influence sex differences in benzodiazepine use and abuse.

Aromatase promoter I.f is regulated by progesterone receptor in mouse hypothalamic neuronal cell lines

Aromatase catalyzes the conversion of C(19) steroids to estrogens. Aromatase and progesterone, both of which function at different steps of steroidogenesis, are crucial for the sexually dimorphic development of the fetal brain and the regulation of gonadotropin secretion and sexual interest in adults. The aromatase gene (Cyp19a1) is selectively expressed in distinct neurons of the mouse hypothalamus through a distal brain-specific promoter, I.f, located ∼40 kb upstream of the coding region. However, the regulation of aromatase expression in the brain is not well understood. In this study, we investigated a short feedback effect of progesterone analogues on aromatase mRNA expression and enzyme activity in estrogen receptor α (Esr1)-positive or -negative mouse embryonic hypothalamic neuronal cell lines that express aromatase via promoter I.f. In a hypothalamic neuronal cell line that highly expresses aromatase, progesterone receptor (Pgr), and Esr1, a progesterone agonist, R5020, inhibited aromatase mRNA level and enzyme activity. The inhibitory effect of R5020 was reversed by its antagonist, RU486. Deletion mutants of promoter I.f suggested that inhibition of aromatase expression by progesterone is conferred by the nt -1000/-500 region, and R5020 enhanced binding of Pgr to the nt -800/-600 region of promoter I.f. Small interfering RNA knockdown of Pgr eliminated progesterone-dependent inhibition of aromatase mRNA and enzyme activity. Taken together, progesterone enhances recruitment of Pgr to specific regions of the promoter I.f of Cyp19a1 and regulates aromatase expression in hypothalamic neurons.

Mechanisms responsible for progesterone's protection against lordosis-inhibiting effects of restraint I. Role of progesterone receptors

Progestins and antiprogestins are widely used therapeutic agents in humans. In many cases, these are indicated for the treatment of reproductive activities. However, progesterone has widespread physiological effects including a reduction of the response to stress. We have reported that 5 min of restraint reduced lordosis behavior of ovariectomized rats hormonally primed with estradiol benzoate. When ovariectomized rats received both estradiol benzoate and progesterone priming, restraint had minimal effects on lordosis. Progesterone influences behavior through classical intracellular progesterone receptor-mediated nuclear events as well as extranuclear events. How these multiple events contribute to the response to stress is unclear. The current project was designed to initiate examination of the mechanisms responsible for progesterone's ability to protect against the effects of the restraint. In the first experiment, ovariectomized rats, primed with 10 μg estradiol benzoate, received 500 μg progesterone 4 h, 1 h, or 30 min before restraint. When progesterone was injected 4h before restraint, progesterone eliminated the effects of restraint. In contrast, progesterone 30 min before restraint offered no protection. Effects of progesterone 1h before restraint were equivocal allowing the suggestion that less than 4h of progesterone priming might be sufficient. In the second experiment, the synthetic progestin, medroxyprogesterone, was shown to mimic effects of progesterone in preventing effects of restraint. Finally, the progesterone receptor antagonist, RU486, attenuated progesterone's protection against restraint. These findings offer evidence that ligand-activated progesterone receptor mechanisms contribute to the maintenance of lordosis behavior in the presence of mild stress.

Physiological doses of progesterone potentiate the effects of triazolam in healthy, premenopausal women

RATIONALE

Gender plays a critical role in the effects of drugs and drug abuse liability. Biological factors, including ovarian hormones, may contribute to gender differences in drug abuse. Preclinical and some clinical research suggests that progesterone and its metabolites have activity at the GABA(A) receptor and may enhance the effect of GABAergic compounds (e.g., benzodiazepines). Because women are exposed to varying levels of progesterone from puberty until menopause, and appear more sensitive to the negative consequences of benzodiazepine use, it is important to understand the impact of progesterone on GABAergic drug effects.

OBJECTIVES

The purpose of this experiment was to characterize the behavioral effects of progesterone, alone and in combination with the short-acting benzodiazepine, triazolam, to determine if progesterone potentiates the behavioral effects of triazolam.

METHODS

Oral micronized progesterone (0, 100, and 200 mg) and oral triazolam (0.00, 0.12, and 0.25 mg/70 kg) were administered to healthy, premenopausal women (n = 11) under conditions of low circulating sex hormones. The subjective, performance and physiological effects of progesterone, alone and in combination with triazolam, were assessed.

RESULTS

Triazolam alone produced prototypical sedative-like effects. Progesterone alone also engendered some sedative effects, although the time course of the effects was more limited than that of triazolam. Progesterone increased and extended the duration of triazolam effects and delayed the onset of triazolam peak effects, most notably at the 0.12 mg/70 kg dose.

CONCLUSIONS

Progesterone potentiates the behavioral effects of benzodiazepines and may contribute to benzodiazepine use and abuse among women.

Neurosteroids in clinical practice: implications for women’s health

The steroidogenic endocrine glands and local synthesis both contribute to the pool of steroids present in the central nervous system (CNS) and peripheral nervous system (PNS). Although the synthesis of neurosteroids in the nervous system is now well established, the spectrum of respective functions in regulating neuronal and glial functions remains to be fully elucidated. From the concept of neurosteroids derives another therapeutical strategy: the use of pharmaceutical agents that increase the synthesis of endogenous neurosteroids within the nervous system. This approach is so far hampered by the lack of knowledge concerning the regulation of the biosynthetic pathways of neurosteroids and their relationship with sex steroids produced by peripheral glands. The present review summarizes some of the available clinical and experimental findings supporting the critical role of neuro-steroids during the fertile life and reproductive aging and their relationship with endogenous and exogenous sex steroids. Brain metabolism of synthethic progestins and the implication of dehydroepiandrosterone (DHEA) treatment in post-menopausal women will be also discussed.

Menopause and Mental Well-Being: Timing of Symptoms and Timing of Hormone Treatment

In the aftermath of the Women's Health Initiative studies, both the clinical and basic science communities had to sort out divergent results among experimental findings, observational data and randomized controlled trials in order to establish a shared analysis. The scientific community formally debates the role of different HRT formulations, hormone doses, time of treatment initiation since the menopause and the age of treated women. Basic scientists demonstrated that the multiple neuroprotective effects of estrogen on brain cells may induce a differential biological response according to the time of treatment. Progesterone (but not all synthetic progestins) also has pivotal neuroactive functions in animal models of reproductive aging. Additionally, epidemiological surveys provide information regarding the detrimental role of hypogonadism on mental well-being. The present article briefly summarizes current evidence supporting the neuroactive role of estrogen, with reference to the clinical finding sustaining the intriguing hypothesis of the early female brain senescence as a highly responsive period to estrogen treatment.

Cyproterone to treat aggressivity in dementia: a clinical case and systematic review

Aggressivity is a common problem in the management of elderly patients with dementia. Medications currently used to diminish aggressive behaviour in dementia can have problematic side effects. We present a case and systematic review of the current knowledge about the use of cyproterone acetate to treat aggressivity (excluding hypersexuality related behaviours) in dementia. An 82-year-old man required psychiatric inpatient admission due to agitation and aggressivity and was diagnosed with Alzheimer's disease. After failed trials of atypical antipsychotics (quetiapine 100 mg/day and risperidone 1 mg/day), drugs for dementia (memantine 20 mg/day and rivastigmine 9 mg/day) and benzodiazepines (lorazepam 0.5-1 mg prn) he was started on cyproterone acetate titrated up to 50 mg twice daily. After two weeks he was calmer and did not express aggressivity. Two months later he was discharged to a community placement where he subsequently remained settled on cyproterone. We reviewed literature on the use of cyproterone in aggressivity (excluding hypersexuality) associated with dementia. We searched the main medical databases including articles in English, Spanish, French and Italian. Only one randomized double-blind trial was found, comparing cyproterone with haloperidol (n = 27). Cyproterone was more effective controlling aggressivity and had lower incidence of side effects. In the one uncontrolled naturalistic observational study identified (n = 19), cyproterone was associated with significant reductions in aggressivity without causing major side effects. Further literature was limited to theoretical discussions. Despite there being evidence to support our observations of a useful role for cyproterone in aggressivity in dementia, further studies are needed to establish the efficacy and safety of this therapeutic option.

Metformin administration restores allopregnanolone response to adrenocorticotropic hormone (ACTH) stimulation in overweight hyperinsulinemic patients with PCOS

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.

Medroxyprogesterone acetate impairs memory and alters the GABAergic system in aged surgically menopausal rats

In women, medroxyprogesterone acetate (MPA) is the most commonly used progestin component of hormone therapy (HT). In vitro, MPA negatively impacts markers of neuronal health and exacerbates experimentally-induced neurotoxicity. There is in vitro evidence that these factors are driven by GABAergic and neurotrophic systems. Whether these effects translate to a negative impact on brain function has not been tested in vivo, clinically or preclinically. Here we evaluate the mnemonic and neurobiological effects of MPA in the surgically menopausal rat. Aged ovariectomized (OVX) rats were given subcutaneous vehicle, natural progesterone, low-dose MPA or high-dose MPA. Multiple cognitive domains were analyzed via the water radial-arm maze (WRAM) and Morris maze (MM). Cognitive brain regions were assayed for changes in the GABAergic system by evaluating GAD protein, the synthesizing enzyme for GABA, and neurotrophins. On the WRAM, both progestin types impaired learning. Further, high-dose MPA impaired delayed memory retention on the WRAM, and exacerbated overnight forgetting on the MM. While neurotrophins were not affected by progesterone or MPA treatment, both progestin types altered GAD levels. MPA significantly and progesterone marginally decreased GAD levels in the hippocampus, and both MPA and progesterone significantly increased GAD levels in the entorhinal cortex. These findings suggest that MPA, the most commonly used progestin in HT, is detrimental to learning and two types of memory, and modulates the GABAergic system in cognitive brain regions, in aged surgically menopausal rats. These findings, combined with in vitro evidence that MPA is detrimental to neuronal health, indicates that MPA has negative effects for brain health and function.

Impact of sex steroids on neuroinflammatory processes and experimental multiple sclerosis

Synthetic and natural estrogens as well as progestins modulate neuronal development and activity. Neurons and glia are endowed with high-affinity steroid receptors. Besides regulating brain physiology, both steroids conciliate neuroprotection against toxicity and neurodegeneration. The majority of data derive from in vitro studies, although more recently, animal models have proven the efficaciousness of steroids as neuroprotective factors. Indications for a safeguarding role also emerge from first clinical trials. Gender-specific prevalence of degenerative disorders might be associated with the loss of hormonal activity or steroid malfunctions. Our studies and evidence from the literature support the view that steroids attenuate neuroinflammation by reducing the pro-inflammatory property of astrocytes. This effect appears variable depending on the brain region and toxic condition. Both hormones can individually mediate protection, but they are more effective in cooperation. A second research line, using an animal model for multiple sclerosis, provides evidence that steroids achieve remyelination after demyelination. The underlying cellular mechanisms involve interactions with astroglia, insulin-like growth factor-1 responses, and the recruitment of oligodendrocytes.

Progestogens and estrogen influence impulsive burying and avoidant freezing behavior of naturally cycling and ovariectomized rats

Steroid hormones, progesterone and estradiol, may influence approach and/or anxiety behavior. Female rats in behavioral estrous, have elevated levels of these steroid hormones and demonstrate more approach and less anxiety behavior than do diestrous rats. Ovariectomy obviates these cyclic variations and systemic progesterone and/or estrogen replacement can enhance approach and anti-anxiety behavior. However, the role of progesterone and/or estrogen in mediating impulsive, avoidant and/or fear behaviors requires further investigation. We hypothesized that if progesterone and/or estrogen influences impulsivity and/or fear then rats in behavioral estrous would demonstrate less impulsive behavior in a burying task and freezing behavior in a conditioned fear task than will diestrous rats. Ovariectomized rats administered progesterone and/or estrogen would show less impulsive burying and freezing behaviors than will vehicle-administered rats. Experiment 1: Naturally cycling rats were tested in marble burying or conditioned fear when they were in behavioral estrous or diestrous. Experiment 2: Ovariectomized rats were administered progesterone, estrogen or vehicle, then tested in marble burying or conditioned fear. Results of Experiment 1 show rats in behavioral estrous demonstrate less impulsive burying and less freezing behavior than diestrous rats. Results of Experiment 2 show administration of progesterone or both estrogen and progesterone decreases impulsive burying and each decrease freezing behavior compared to vehicle. Thus, progesterone and/or estrogen may mediate impulsive and/or avoidant behavior.