Allopregnanolone and its antagonist modulate neuroinflammation and neurological impairment.

Neuroinflammation accompanies several brain disorders, either as a secondary consequence or as a primary cause and may contribute importantly to disease pathogenesis. Neurosteroids which act as Positive Steroid Allosteric GABA-A receptor Modulators (Steroid-PAM) appear to modulate neuroinflammation and their levels in the brain may vary because of increased or decreased local production or import from the systemic circulation. The increased synthesis of steroid-PAMs is possibly due to increased expression of the mitochondrial cholesterol transporting protein (TSPO) in neuroinflammatory tissue, and reduced production may be due to changes in the enzymatic activity. Microglia and astrocytes play an important role in neuroinflammation, and their production of inflammatory mediators can be both activated and inhibited by steroid-PAMs and GABA. What is surprising is the finding that both allopregnanolone, a steroid-PAM, and golexanolone, a novel GABA-A receptor modulating steroid antagonist (GAMSA), can inhibit microglia and astrocyte activation and normalize their function. This review focuses on the role of steroid-PAMs in neuroinflammation and their importance in new therapeutic approaches to CNS and liver disease.

Extra-Synaptic GABAA Receptor Potentiation and Neurosteroid-Induced Learning Deficits Are Inhibited by GR3027, a GABAA Modulating Steroid Antagonist.

Objectives In Vitro: To study the effects of GR3027 (golexanolone) on neurosteroid-induced GABA-mediated current responses under physiological GABAergic conditions with recombinant human α5ß3γ2L and α1ß2γ2L GABAA receptors expressed in human embryonic kidney cells, using the response patch clamp technique combined with the Dynaflow™ application system. With α5ß3γ2L receptors, 0.01-3 µM GR3027, in a concentration-dependent manner, reduced the current response induced by 200 nM THDOC + 0.3 µM GABA, as well as the THDOC-induced direct gated effect. GR3027 (1 µM) alone had no effect on the GABA-mediated current response or current in the absence of GABA. With α1ß2γ2L receptors, GR3027 alone had no effect on the GABA-mediated current response or did not affect the receptor by itself. Meanwhile, 1-3 µM GR3027 reduced the current response induced by 200 nM THDOC + 30 µM GABA and 3 µM GR3027 that induced by 200 nM THDOC when GABA was not present. Objectives In Vivo: GR3027 reduces allopregnanolone (AP)-induced decreased learning and anesthesia in male Wistar rats. Rats treated i.v. with AP (2.2 mg/kg) or vehicle were given GR3027 in ratios of 1:0.5 to 1:5 dissolved in 10% 2-hydroxypropyl-beta-cyclodextrin. A dose ratio of AP:GR3027 of at least 1:2.5 antagonized the AP-induced decreased learning in the Morris Water Mase (MWM) and 1:7.5 antagonized the loss of righting reflex (LoR). GR3027 treatment did not change other functions in the rat compared to the vehicle group. Conclusions: GR3027 functions in vitro as an inhibitor of GABAA receptors holding α5ß3γ2L and α1ß2γ2L, in vivo, in the rat, as a dose-dependent inhibitor toward AP's negative effects on LoR and learning in the MWM.

The GABA system, a new target for medications against cognitive impairment-Associated with neuroactive steroids.

The prevalence of cognitive dysfunction, dementia, and neurodegenerative disorders such as Alzheimer's disease (AD) is increasing in parallel with an aging population. Distinct types of chronic stress are thought to be instrumental in the development of cognitive impairment in central nervous system (CNS) disorders where cognitive impairment is a major unmet medical need. Increased GABAergic tone is a mediator of stress effects but is also a result of other factors in CNS disorders. Positive GABA-A receptor modulating stress and sex steroids (steroid-PAMs) such as allopregnanolone (ALLO) and medroxyprogesterone acetate can provoke impaired cognition. As such, ALLO impairs memory and learning in both animals and humans. In transgenic AD animal studies, continuous exposure to ALLO at physiological levels impairs cognition and increases degenerative AD pathology, whereas intermittent ALLO injections enhance cognition, indicating pleiotropic functions of ALLO. We have shown that GABA-A receptor modulating steroid antagonists (GAMSAs) can block the acute negative cognitive impairment of ALLO on memory in animal studies and in patients with cognitive impairment due to hepatic encephalopathy. Here we describe disorders affected by steroid-PAMs and opportunities to treat these adverse effects of steroid-PAMs with novel GAMSAs.

Isoallopregnanolone Inhibits Estrus Cycle-Dependent Aggressive Behavior.

Among female rats, some individuals show estrus cycle-dependent irritability/aggressive behaviors, and these individual rats may be used as a model for premenstrual dysphoric disorder (PMDD). We wanted to investigate if these behaviors are related to the estrus cycle phase containing moderately increased levels of positive GABA-A receptor-modulating steroids (steroid-PAM), especially allopregnanolone (ALLO), and if the adverse behavior can be antagonized. The electrophysiology studies in this paper show that isoallopregnanolone (ISO) is a GABA-A-modulating steroid antagonist (GAMSA), meaning that ISO can antagonize the agonistic effects of positive GABA-A receptor-modulating steroids in both α1ß2γ2L and α4ß3δ GABA-A receptor subtypes. In this study, we also investigated whether ISO could antagonize the estrus cycle-dependent aggressive behaviors in female Wistar rats using a resident-intruder test. Our results confirmed previous reports of estrus cycle-dependent behaviors in that 42% of the tested rats showed higher levels of irritability/aggression at diestrus compared to those at estrus. Furthermore, we found that, during the treatment with ISO, the aggressive behavior at diestrus was alleviated to a level comparable to that of estrus. We noticed an 89% reduction in the increase in aggressive behavior at diestrus compared to that at estrus. Vehicle treatment in the same animals showed a minimal effect on the diestrus-related aggressive behavior. In conclusion, we showed that ISO can antagonize Steroid-PAM both in α1ß2γ2L and α4ß3δ GABA-A receptor subtypes and inhibit estrus cycle-dependent aggressive behavior.

Altered GABAA receptor function in women with endometriosis: a possible pain-related mechanism.

INTRODUCTION: The mechanism underlying endometriosis-related pain remains poorly understood. Previous studies have indicated that γ-aminobutyric acid (GABA) type A (GABAA ) receptors and GABAergic substances (eg endogenous neurosteroids) play important mechanistic roles in various pain conditions. Our primary objective was to compare GABAA receptor function between women with endometriosis and healthy controls by performing a challenge test with diazepam, a GABAA receptor agonist, using the saccadic eye velocity as the main outcome. The secondary objective was to investigate the relation between GABAA receptor function and serum levels of allopregnanolone, an endogenous positive modulator of the GABAA receptor, in the participating women. MATERIAL AND METHODS: 15 women with pelvic pain and laparoscopically confirmed endometriosis and 10 healthy, symptom-free, control women, aged 18-40 years, underwent the diazepam challenge test during the follicular phase of the menstrual cycle. Basal serum allopregnanolone levels were measured prior to diazepam injection. RESULTS: Compared with healthy controls, women with pelvic pain and confirmed endometriosis had a significantly smaller change in saccadic eye velocity after GABAA receptor stimulation with diazepam, indicating lower sensitivity to diazepam. The saccadic eye velocity response was not correlated with the serum allopregnanolone levels. CONCLUSIONS: Women with painful endometriosis show altered GABAA receptor function, depicted as a muted response to an exogenous GABAA receptor agonist.

Neurosteroid Activation of GABA-A Receptors: A Potential Treatment Target for Symptoms in Primary Biliary Cholangitis?

Background and Aims: A third of patients with primary biliary cholangitis (PBC) experience poorly understood cognitive symptoms, with a significant impact on quality of life (QOL), and no effective medical treatment. Allopregnanolone, a neurosteroid, is a positive allosteric modulator of gamma-aminobutyricacid-A (GABA-A) receptors, associated with disordered mood, cognition, and memory. This study explored associations between allopregnanolone and a disease-specific QOL scoring system (PBC-40) in PBC patients. Method: Serum allopregnanolone levels were measured in 120 phenotyped PBC patients and 40 age and gender-matched healthy controls. PBC subjects completed the PBC-40 at recruitment. Serum allopregnanolone levels were compared across PBC-40 domains for those with none/mild symptoms versus severe symptoms. Results: There were no overall differences in allopregnanolone levels between healthy controls (median = 0.03 ng/ml (IQR = 0.025)) and PBC patients (0.031 (0.42), p = 0.42). Within the PBC cohort, higher allopregnanolone levels were observed in younger patients (r (120) = -0.53, p < 0.001) but not healthy controls (r (39) = -0.21, p = 0.21). Allopregnanolone levels were elevated in the PBC-40 domains, cognition (u = 1034, p = 0.02), emotional (u = 1374, p = 0.004), and itch (u = 795, p = 0.03). Severe cognitive symptoms associated with a younger age: severe (50 (12)) vs. none (60 (13); u = 423 p = 0.001). Conclusion: Elevated serum allopregnanolone is associated with severe cognitive, emotional, and itch symptoms in PBC, in keeping with its known action on GABA-A receptors. Existing novel compounds targeting allopregnanolone could offer new therapies in severely symptomatic PBC, satisfying a significant unmet need.

Golexanolone, a GABAA receptor modulating steroid antagonist, restores motor coordination and cognitive function in hyperammonemic rats by dual effects on peripheral inflammation and neuroinflammation.

AIMS: Hyperammonemic rats show peripheral inflammation, increased GABAergic neurotransmission and neuroinflammation in cerebellum and hippocampus which induce motor incoordination and cognitive impairment. Neuroinflammation enhances GABAergic neurotransmission in cerebellum by enhancing the TNFR1-glutaminase-GAT3 and TNFR1-CCL2-TrkB-KCC2 pathways. Golexanolone reduces GABAA receptors potentiation by allopregnanolone. This work aimed to assess if treatment of hyperammonemic rats with golexanolone reduces peripheral inflammation and neuroinflammation and restores cognitive and motor function and to analyze underlying mechanisms. METHODS: Rats were treated with golexanolone and effects on peripheral inflammation, neuroinflammation, TNFR1-glutaminase-GAT3 and TNFR1-CCL2-TrkB-KCC2 pathways, and cognitive and motor function were analyzed. RESULTS: Hyperammonemic rats show increased TNFα and reduced IL-10 in plasma, microglia and astrocytes activation in cerebellum and hippocampus, and impaired motor coordination and spatial and short-term memories. Treating hyperammonemic rats with golexanolone reversed changes in peripheral inflammation, microglia and astrocytes activation and restored motor coordination and spatial and short-term memory. This was associated with reversal of the hyperammonemia-enhanced activation in cerebellum of the TNFR1-glutaminase-GAT3 and TNFR1-CCL2-TrkB-KCC2 pathways. CONCLUSION: Reducing GABAA receptors activation with golexanolone reduces peripheral inflammation and neuroinflammation and improves cognitive and motor function in hyperammonemic rats. The effects identified would also occur in patients with hepatic encephalopathy and, likely, in other pathologies associated with neuroinflammation.

Medroxyprogesterone acetate positively modulates specific GABAA-receptor subtypes - affecting memory and cognition.

Medroxyprogesterone acetate (MPA) is a progestin widely used in humans as hormone replacement therapy and at other indications. Many progestin metabolites, as the progesterone metabolite allopregnanolone, have GABAA-receptor modulatory effects and are known to affect memory, learning, appetite, and mood. In women, 4 years chronic treatment with MPA doubles the frequency of dementia and in rats, MPA causes cognitive impairment related to the GABAergic system. Activation of the membrane bound GABAA receptor results in a chloride ion flux that can be studied by whole-cell patch-clamp electrophysiological recordings. The purpose of this study was to clarify the modulatory effects of MPA and specific MPA metabolites, with structures like known GABAA-receptor modulators, on different GABAA-receptor subtypes. An additional aim was to verify the results as steroid effects on GABA response in single cells taken from rat hypothalamus. HEK-293 cell-lines permanently expressing the recombinant human GABAA-receptor subtype α1ß2γ2L or α5ß3γ2L or α2ß3γ2S were created. The MPA metabolites 3α5α-MPA,3ß5α-MPA and 3ß5ß-MPA were synthesised and purified for electrophysiological patch-clamp measurements with a Dynaflow system. The effects of MPA and tetrahydrodeoxycorticosterone were also studied. None of the studied MPA metabolites affected the responses mediated by α1ß2γ2L or α5ß3γ2L GABAA receptors. Contrary, MPA clearly acted both as a positive modulator and as a direct activator of the α5ß3γ2L and α2ß3γ2S GABAA receptors. However, in concentrations up to 10 µM, MPA was inactive at the α1ß2γ2L GABAA receptor. In the patch-clamp recordings from dissociated cells of the preoptic area in rats, MPA increased the amplitude of responses to GABA. In addition, MPA alone without added GABA, evoked a current response. In conclusion, MPA acts as a positive modulator of specific GABAA receptor subtypes expressed in HEK cells and at native GABA receptors in single cells from the hypothalamic preoptic area.

Positive GABAA receptor modulating steroids and their antagonists: Implications for clinical treatments.

GABA is the main inhibitory neurotransmitter in the brain and GABAergic transmission has been shown to be of importance for regulation of mood, memory and food intake. The progesterone metabolite allopregnanolone (Allo) is a positive GABAA receptor modulating steroid with potent effects. In humans, disorders such as premenstrual dysphoric disorder (PMDD), hepatic encephalopathy and polycystic ovarian syndrome are associated with elevated Allo levels and increased negative mood, disturbed memory and increased food intake in some individuals. This is surprising because Allo shares many properties with benzodiazepines and is mainly considered to be anxiolytic and anti-depressant. However, it is well established that, in certain individuals, GABAA receptor activating compounds could have paradoxical effects and thus be anxiogenic in low physiological plasma concentrations but anxiolytic at high levels. We have demonstrated that isoallopregnanolone (Isoallo), the 3ß-OH sibling of Allo, functions as a GABAA receptor modulating steroid antagonist (GAMSA) but without any effects of its own on GABAA receptors. The antagonistic effect is noted in most GABAA subtypes investigated in vitro to date. In vivo, Isoallo can inhibit Allo-induced anaesthesia in rats, as well as sedation or saccadic eye velocity in humans. Isoallo treatment has been studied in women with PMDD. In a first phase II study, Isoallo (Sepranolone; Asarina Pharma) injections significantly ameliorated negative mood in women with PMDD compared with placebo. Several GAMSAs for oral administration have also been developed. The GAMSA, UC1011, can inhibit Allo induced memory disturbances in rats and an oral GAMSA, GR3027, has been shown to restore learning and motor coordination in rats with hepatic encephalopathy. In humans, vigilance, cognition and pathological electroencephalogram were improved in patients with hepatic encephalopathy on treatment with GR3027. In conclusion GAMSAs are a new possible treatment for disorders and symptoms caused by hyperactivity in the GABAA system.

A randomized, double-blind study on efficacy and safety of sepranolone in premenstrual dysphoric disorder.

Women with premenstrual dysphoric disorder (PMDD) experience mood symptoms related to the increase in progesterone and the neuroactive steroid allopregnanolone. Our hypothesis is that allopregnanolone is the symptom provoking factor. The rationale for the present study was to treat PMDD patients with the GABAA receptor modulating steroid antagonist, sepranolone (isoallopregnanolone). Patients (n = 206) with PMDD from 12 European centers were randomized in a parallel double-blind study and treated with placebo, sepranolone 10 mg and 16 mg. Patients administered sepranolone subcutaneously every 48 h during the 14 premenstrual days of three consecutive menstrual cycles. After obtaining informed consent, the PMDD diagnosis was confirmed according to DSM-5 and verified with two menstrual cycles of daily symptom ratings using the Daily Record of Severity of Problems (DRSP) scale in an eDiary. Inclusion and exclusion criteria stipulated that the women should be essentially healthy, not pregnant, have no ongoing psychiatric disorder or take interfering medications, and have regular menstrual cycles. The study's primary endpoint was the Total symptom score (Sum21, the score for all 21 symptom questions in the DRSP). In the prespecified statistical analysis the average score of the 5 worst premenstrual days in treatment cycles 2 and 3 were subtracted from the corresponding average score in the two diagnostic cycles. The treatment effects were tested using analysis of variance in a hierarchal order starting with the combined active sepranolone treatments vs. placebo. The prespecified analysis of Sum21 showed a large treatment effect of all three treatments but no statistically significant difference to placebo. However, the ratings of distress showed a significant treatment effect of sepranolone compared to placebo (p = 0.037) and the ratings of impairment showed a trend to greater treatment effect of sepranolone compared to placebo. Many women with PMDD had symptoms during a longer period than the late luteal phase. It has previously been shown that 9 premenstrual days may be more representative for comparison of PMDD symptom periods than the 5 worst premenstrual days. A post hoc analysis was undertaken in the per protocol population investigating the treatment effect during 9 premenstrual days in the third treatment cycle. The Sum21 results of this analysis showed that the sepranolone 10 mg was significantly better than placebo (p = 0.008). Similar significant treatment effects were found for the impairment and distress scores. A significantly larger number of individuals experienced no or minimal symptoms (Sum21 <42 points) with the 10 mg sepranolone treatment compared to placebo (p = 0.020). The results indicate that there is an attenuating effect by sepranolone on symptoms, impairment, and distress in women with PMDD especially by the 10 mg dosage. Sepranolone was well tolerated, and no safety concerns were identified.

A pilot study of golexanolone, a new GABA-A receptor-modulating steroid antagonist, in patients with covert hepatic encephalopathy.

BACKGROUND & AIMS: Golexanolone is a novel small molecule GABA-A receptor-modulating steroid antagonist under development for the treatment of cognitive and vigilance disorders caused by allosteric over-activation of GABA-A receptors by neurosteroids. It restored spatial learning and motor coordination in animal models of hepatic encephalopathy (HE) and mitigated the effects of intravenous allopregnanolone in healthy adults in a dose-dependent fashion. Herein, we report data on the safety, pharmacokinetics (PK) and efficacy of golexanolone in adult patients with cirrhosis. METHODS: Following single/multiple ascending dose studies, adults with Child-Pugh A/B cirrhosis and abnormal continuous reaction time (CRT) on screening were randomized to 3 weeks' dosing with golexanolone (10, 40 or 80 mg BID) or placebo. CRT, psychometric hepatic encephalopathy score (PHES), animal naming test (ANT), Epworth sleepiness scale (ESS) and electroencephalogram (mean dominant frequency [MDF]; delta+theta/alpha+beta ratio [DT/AB]) were obtained at baseline, 10, and 21 days. RESULTS: Golexanolone exhibited satisfactory safety and PK. Baseline characteristics were similar between the 12 and 33 patients randomized to placebo or golexanolone, respectively. By prespecified analyses, golexanolone was associated with directionally favourable changes vs. placebo in ESS (p = 0.047), MDF (p = 0.142) and DT/AB (p = 0.021). All patients also showed directionally favourable changes in CRT, PHES and ANT, but with no statistical difference between golexanolone and placebo. Post hoc analyses taking into account the variability and improvement in CRT, PHES and ANT observed between screening and baseline suggested an efficacy signal by cognitive measures as well. CONCLUSION: Golexanolone was well tolerated and associated with improvement in cognitive performance. These results implicate GABA-A receptor-modulating neurosteroids in the pathogenesis of HE and support the therapeutic potential of golexanolone. LAY SUMMARY: Many patients with cirrhosis experience subtle but disabling cognitive problems, including sleepiness and poor attention span, that impair their ability to be gainfully employed or carry out activities of daily living. This pilot study tested the hypothesis that these problems with cognition, for which there is no approved treatment, might be improved by an experimental drug, golexanolone, designed to normalize the function of receptors which inhibit brain function. The results of this study suggest that golexanolone is well tolerated and may improve cognition, as reflected by measures of sleepiness, attention span and brain wave activity, paving the way for future larger studies of this promising experimental drug. CLINICAL TRIAL REGISTRATION NUMBER: EudraCT 2016-003651-30.

Neurosteroid involvement in threatened preterm labour.

Introduction: The neurosteroid allopregnanolone modulates oxytocin expression in the brain, and its effects arise from its action on the GABAA receptor. Whether neurosteroid levels and the function of the GABAA receptor are involved in the risk of preterm labour in pregnant women is unknown. Methods: Pregnant women with (n = 16) or without (n = 20) threatened preterm labour (TPL) in gestational week 33 + 6 days to 37 + 0 days were studied prospectively with procedures including foetal heart rate monitoring, vaginal examination, ultrasound examination and blood tests to determine allopregnanolone, progesterone and oxytocin levels. The GABAA receptor function in both groups was measured with a saccadic eye velocity test (SEVT). Results: Plasma oxytocin levels were higher in the TPL group than in the control group (41.5 vs. 37.0 pmol/L, respectively, p = .021). Although the allopregnanolone and progesterone levels in both groups did not differ, there was a negative association between blood oxytocin and allopregnanolone (as predictor) levels in the TPL group (B: -3.2, 95% confidence interval (CI): -5.5 to -0.9, p = .012). As a predictor of TPL, progesterone was associated with cervix maturity (odds ratio: 1.02, 95% CI: 1.00-1.04, p = .038). SEVT showed that the women in both groups had similar GABAA receptor functions. In both groups, body mass index correlated with peak saccadic eye velocity (r = .34, p = .044) and negatively with allopregnanolone (r = -.41, p = .013). Conclusions: Neurosteroid levels were unchanged in the peripheral blood of women with TPL, despite the increase in available oxytocin. Although the function of the GABAA receptor was unchanged in women with TPL, to ensure reliable results, saccadic eye velocity should be investigated during a challenge test with a GABAA receptor agonist.

Body fat percentage and CRP correlates with a composite score of vascular risk markers in healthy, young adults - The Lifestyle, Biomarkers, and Atherosclerosis (LBA) study.

BACKGROUND: Identification of early signs of atherosclerosis in young adults have the potential to guide early interventions to prevent later cardiovascular disease. We therefore analyzed measures of vascular structure and function and biomarkers of cardiovascular risk in a sample of young healthy adults. METHODS: Pulse-wave velocity (PWV), carotid-intima media thickness (cIMT) and augmentation index (AIX) were measured in 834 healthy non-smokers (ages 18.0-25.9). Emphasis was put on discriminating between individuals having a vascular structure and function associated with a higher or lower risk, and cluster analysis algorithms were employed to assign the subjects into groups based on these vascular measurements. In addition, a vascular status score (VSS) was calculated by summarizing the results according to quintiles of the vascular measurements. The associations between VSS and cardiovascular biomarkers were examined by regression analyses. RESULTS: The cluster analyses did not yield sufficiently distinct clustering (groups of individuals that could be categorized unequivocally as having either a vascular structure and function associated with a higher or lower CVD risk). VSS proved a better classificatory variable. The associations between VSS and biomarkers of cardiovascular risk were analyzed by univariable and multivariable regressions. Only body fat percentage and C-reactive protein (CRP) were independently associated with VSS. CONCLUSIONS: A VSS calculation, which integrates PWV, cIMT, and AIX measurements is better suited for cardiovascular risk evaluation in young adults than cluster analyses. The independent associations of VSS with body fat percentage and CRP highlight the decisive role of adiposity and systemic inflammation in early atherosclerotic progression and suggests a subordinate role of insulin and lipid metabolism in this age span.

Isoallopregnanolone reduces tic-like behaviours in the D1CT-7 mouse model of Tourette syndrome.

Tourette syndrome (TS) is a neuropsychiatric disorder characterised by multiple, persistent tics. These semi-voluntary motor and phonic manifestations are typically aggravated by exposure to acute stress, yet the mechanisms underlying this exacerbation remain unclear. Using a well-characterised animal model of TS, the D1CT-7 mouse, we recently showed that acute stress increases tic-like responses and causes sensorimotor gating deficits, as measured by the prepulse inhibition of the startle. We showed that these effects are promoted by the brain synthesis of the neurosteroid allopregnanolone (AP). In line with this idea, inhibition of AP synthesis by finasteride was found to suppress the tic-exacerbating effects of stress; conversely, AP administration resulted in a marked enhancement of the number of tic-like motor bursts. Given that the primary mechanism of AP is based on the positive allosteric modulation of GABAA receptors, in the present study, we hypothesised that the enhancement in tic-like behaviours induced by either stress or AP may be countered by isoallopregnanolone (isoAP), the natural 3ß-epimer of AP that acts as an antagonist to the AP-binding site within GABAA receptors. In agreement with our hypothesis, isoAP (5-10 mg kg-1 , s.c.) dose-dependently reduced the number of tic-like behaviours induced by stress in D1CT-7 mice. These effects were comparable to those elicited by both the benchmark TS therapy haloperidol (0.3 mg kg-1 , i.p.), as well as finasteride (25 mg kg-1 , i.p.). IsoAP also countered the prepulse inhibition deficits secondary to stress in D1CT-7 mice. Finally, isoAP opposed the enhancement of tic-like behaviours induced by AP (15 mg kg-1 , i.p.). Given that isoAP is well-tolerated and has an optimal safety profile, these data suggest that this steroid may have therapeutic properties in TS.

The additive effect of allopregnanolone on ghrelin's orexigenic effect in rats.

The progesterone metabolite, allopregnanolone (AlloP), is a GABAA receptor modulating steroid and is known to have orexigenic and pro-obesity effects. The neurobiological mechanisms underpinning these effects are most likely due to enhanced GABAergic signaling in the lateral arcuate nucleus (ARC) and medial paraventricular nucleus (PVN) of the hypothalamus. Inspired by the finding that GABAergic signaling is also important for the orexigenic effects of the circulating hormone, ghrelin, we sought to determine the extent to which AlloP (one of the most potent endogenous GABAA-receptor modulators) operates alongside ghrelin to enhance food intake. Male rats with ad libitum access to standard chow were injected intravenously with AlloP and/or ghrelin, alone or in combination. The intake of the standard chow was greater after AlloP 1 mg/kg together with ghrelin 30 µg/kg than with 30 µg/kg ghrelin alone. Food intake was also increased for the combined treatment of AlloP 0.5 mg/kg + ghrelin 10 µg/kg, AlloP 1 mg/kg + ghrelin 10 µg/kg, and AlloP 0.5 mg/kg + ghrelin 30 µg/kg. There was no significant difference in food intake between the two ghrelin doses or between the two doses of AlloP and the vehicle. In electrophysiological studies, physiologically relevant concentrations of AlloP prolonged the current decay time of spontaneous inhibitory post-synaptic current of dissociated cells of the ARC and PVN. We conclude that AlloP enhances the hyperphagic effect of ghrelin, findings of potential relevance for the hyperphagia associated with the luteal phase of the reproductive cycle.

Changes in premenstrual symptoms in women starting or discontinuing use of oral contraceptives.

It is not clear whether oral contraceptive (OC) treatment affects premenstrual symptoms in women. The aim of the present study was to evaluate changes in premenstrual symptoms (PMS) in women starting to use or discontinuing the use of OCs. Twenty-four healthy women with no previous diagnosis of premenstrual dysphoric disorder were included in this study with a prospective crossover design. Nineteen women completed daily ratings of somatic and mood symptoms during two hormonally different cycles, during a normal menstrual cycle and while using OCs. The menstrual cycle phases were hormonally verified and the low-dose, monophasic OCs were used in a 21/7 regimen. The onset of OC use significantly decreased premenstrual somatic symptoms, but it did not affect mood symptoms. In the women who discontinued OC use, no significant changes in neither somatic nor mood symptoms appeared in the premenstrual phase.

GR3027 reversal of neurosteroid-induced, GABA-A receptor-mediated inhibition of human brain function: an allopregnanolone challenge study.

RATIONALE: GR3027 is a novel small molecule GABA-A receptor-modulating steroid antagonist, which in non-clinical studies has shown promise for treatment of human disorders due to allosteric over-activation of GABA-A receptors by neurosteroids, such as allopregnanolone. We here studied its safety, pharmacokinetics, and ability to inhibit allopregnanolone effects in humans. METHODS: Safety and pharmacokinetics were studied in healthy adult males receiving ascending single or multiple oral GR3027 vs. placebo. GR3027-mediated reversal of allopregnanolone effect on maximal saccadic eye velocity (SEV), and self-rated somnolence was studied in a double-blind, placebo-controlled, three-part cross-over study in which 3 or 30 mg oral GR3027 preceded 0.05 mg/kg of i.v. allopregnanolone. RESULTS: GR3027 was well tolerated, adverse events were generally mild and transient, and no dose-limiting toxicity or grade 3 adverse events were observed up to the highest single (200 mg) or multiple (100 mg every 12 h for 5 days) doses. The maximum concentration (Cmax) and systemic exposure (area under the plasma concentration-time curve from dose extrapolated to infinity [AUC0-∞] and/or AUC during the dosing interval [AUCτ]) varied linearly with dose; with dose-dependent accumulation ratios of 1.3-1.6. Allopregnanolone decreased SEV and induced somnolence in most, but not all subjects. By predefined analyses, 30 mg GR3027 significantly inhibited allopregnanolone-induced decrease in SEV (p = 0.03); 3 and 30 mg GR3027 non-significantly inhibited allopregnanolone-induced sedation. By post hoc analyses restricted to subjects with allopregnanolone-induced changes and the time period over which they occurred, GR3027 dose dependently inhibited allopregnanolone-induced decrease in SEV (p = 0.04 at 30 mg, non-significant at 3 mg) and allopregnanolone-induced sedation (p = 0.01/0.05 at 3/30 mg doses). CONCLUSION: Oral GR3027 mitigates inhibition of brain function induced by allopregnanolone at doses which are clinically well tolerated and associated with linear pharmacokinetics.

Negative Association Between Allopregnanolone and Cerebral Serotonin Transporter Binding in Healthy Women of Fertile Age.

Allopregnanolone is a metabolite of the sex hormone progesterone, with suggested relevance for female mood disorders. While allopregnanolone and serotonin are known to influence psychological well-being, the molecular and psychological specifics of their relationship are to date poorly understood, especially in women of fertile age who experience regular fluctuations of progesterone across the menstrual cycle. Availability of serotonin in the synaptic cleft is regulated by the serotonin transporter (SERT), which can be imaged in the living human brain by use of positron emission tomography (PET) and the radiotracer [11C]DASB. To evaluate sex-specific allopregnanolone-SERT interactions, the present study investigated the relationship between cerebral SERT availability, serum allopregnanolone levels and psychological well-being in women of fertile age. Brain imaging data, self-reported symptoms of mental distress and emotion regulation, and biobank material from ninety healthy women were available from the Center for Integrated Molecular Brain Imaging (CIMBI) database. Age, BMI, and daylight minutes were included as covariates in the analyses and SERT genotype (5-HTTLPR) was considered a potential confounder. Lower serum allopregnanolone levels were associated with higher SERT binding in the prefrontal cortex. Moreover, allopregnanolone levels were negatively associated with measures of alertness, although this finding was not mediated by prefrontal cortex SERT binding. These findings suggest a link between the typical psychological well-being experienced in the follicular phase when allopregnanolone levels are low and higher SERT in the prefrontal cortex, a region for higher cognitive functions and top-down regulation of emotions.

The relationship between weight gain during pregnancy and allopregnanolone levels: a longitudinal study.

OBJECTIVE: Large weight gain during pregnancy is a risk factor for complications for mother and fetus. Hunger and satiety are regulated in the hypothalamus, where the gamma-amino-butyric acid system (GABA) has an important role. Allopregnanolone, a progesterone metabolite, increases during pregnancy and is a potent GABA-A receptor modulating steroid. Allopregnanolone has been shown to induce overeating in rodents. The aim was to investigate whether there is a relationship between weight gain and allopregnanolone concentrations during pregnancy in humans. DESIGN: A longitudinal, cohort study. METHODS: Pregnant women (n = 56) were recruited in primary care in northern Sweden. Allopregnanolone concentrations in plasma were measured using radioimmunoassay and weight was measured in gestational weeks 12 and 35. RESULTS: Weight increase correlated significantly to allopregnanolone in late pregnancy increase (rs = 0.320; P = 0.016), indicating a positive relationship between weight increase and allopregnanolone increase. A positive relationship was also noted between allopregnanolone in the 35th gestational week and weight increase. Women who gained ≥11 kg during pregnancy showed higher allopregnanolone concentrations in week 35 and higher increase compared to women who increased <11 kg (P = 0.006 and P = 0.009 resp.). There was no difference in weight or allopregnanolone concentrations at the onset of pregnancy. CONCLUSIONS: The results show a relationship between weight gain during pregnancy and increase in allopregnanolone concentrations.

Follow-up after early medical abortion: Comparing clinical assessment with self-assessment in a rural hospital in northern Norway.

OBJECTIVES: A follow-up study was performed on women who had requested medical abortions in a rural hospital in northern Norway to compare clinical assessment with self-assessment of early medical abortion in terms of safety. STUDY DESIGN: During the three-year study period, 392 women requested termination of pregnancy. After excluding those who changed their mind, those who had a spontaneous miscarriage, those who were referred to a central hospital for a two-stage abortion, and those who had the abortion performed surgically, 242 cases remained, and all the medical files were reviewed. Five cases (2%) were lost to follow-up, so the study group consists of 237 cases. RESULTS: Out of the 237 cases, in which a medical abortion was performed, 106 were performed at home with a self-assessment (44.7%), and 131 (55.3%) were performed at the department of Gynecology. The percentage of cases with self-assessment did not noticeably change during the three-year study period. The registered complications were infection, incomplete abortion requiring a surgical procedure and hospitalization due to severe pain. No significant difference in registered complications was found between medical abortions with self-assessment (n=9, 8.5% out of 106 cases) and medical abortions at the gynecological out-patient department (n=6, 4.6% out of 131 cases). CONCLUSION: According to this investigation, it is equally safe to perform a medical abortion at home with a self-assessment as it is to have a medical abortion at an outpatient clinic. These results could be useful for health care provision in rural areas where access to hospitals is impeded by logistical difficulties.