Tibolone reverses the cognitive effects caused by leuprolide acetate administration, improving mood and quality of life in patients with symptomatic uterine leiomyomas

[Testosterone and Alzheimer's disease]

Alzheimer's disease (AD) is a neurodegenerative disease that causes dementia in half of the cases. Asthma is usually found in people over 65 years of age. The etiopathogenesis of the disease is multifactorial and includes genetic factors, nutritional disorders, mitochondrial dysfunction, oxidative stress, and aging. Sex hormones have an important influence on the development of AD, as evidenced by a higher incidence in women than in men. Considering the significant influence of T on the maintenance of normal brain function, the present study is aimed at evaluating the impact of androgen deprivation therapy (ADT), as well as testosterone therapy, on the risk of AD development and progression. Although there is some clinical inconsistency between studies, androgens have a significant effect on brain function and are beneficial for AD patients. Low levels of circulating androgens should be considered as a significant risk factor for the development of AD and memory loss. With a reduced level of T in the plasma of men, its administration improves cognitive performance and memory, treatment should be started at an early stage of the disease. In men and women with AD, androgens improve mental state and slow the progression of the disease, providing a protective effect. In the future, it is necessary to conduct studies on a large population, taking into account personality factors and a more specific approach to assessing cognitive functions and the causal relationship of T administration in AD.

Impact of Testosterone on Alzheimer's Disease

Alzheimer’s disease (AD) is a neurodegenerative disease responsible for almost half of all dementia cases in the world and progressively increasing. The etiopathology includes heritability, genetic factors, aging, nutrition, but sex hormones play a relevant role. Animal models demonstrated that testosterone (T) exerted a neuroprotective effect reducing the production of amyloid-beta (Aβ), improving synaptic signaling, and counteracting neuronal death. This study aims to evaluate the impact of T deprivation and T administration in humans on the onset of dementia and AD. A search was conducted on MEDLINE and Scopus for the “androgen deprivation therapy” and “testosterone therapy” with “dementia” and “Alzheimer’s.” Studies lasting twenty years with low risk of bias, randomized clinical trial, and case-controlled studies were considered. Twelve articles on the effect of androgen deprivation therapy (ADT) and AD and seventeen on T therapy and AD were retrieved. Men with prostate cancer under ADT showed a higher incidence of dementia and AD. The effect of T administration in hypogonadal men with AD and cognitive impairment has evidenced some positive results. The majority of studies showed the T administration improved memory and cognition in AD while others did not find any benefit. Although some biases in the studies are evident, T therapy for AD patients may represent an essential clinical therapy to reduce dementia incidence and AD progression. However, more specific case-controlled trials on the effect of androgens therapy in men and women to reducing the onset of AD are necessary.

Tibolone as Hormonal Therapy and Neuroprotective Agent

Tibolone (TIB), a selective tissue estrogenic activity regulator (STEAR) in clinical use by postmenopausal women, activates hormonal receptors in a tissue-specific manner. Estrogenic activity is present mostly in the brain, vagina, and bone, while the inactive forms predominate in the endometrium and breast. Conflicting literature on TIB's actions has been observed. While it has benefits for vasomotor symptoms, bone demineralization, and sexual health, a higher relative risk of hormone-sensitive cancer has been reported. In the brain, TIB can improve mood and cognition, neuroinflammation, and reactive gliosis. This review aims to discuss the systemic effects of TIB on peri- and post-menopausal women and its role in the brain. We suggest that TIB is a hormonal therapy with promising neuroprotective properties.

The synthetic steroid tibolone exerts sex-specific regulation of astrocyte phagocytosis under basal conditions and after an inflammatory challenge

BACKGROUND

Tibolone is a synthetic steroid used in clinical practice for the treatment of climacteric symptoms and osteoporosis. Active metabolites of tibolone, generated in target tissues, have an affinity for estrogen and androgen receptors. Astrocytes are direct targets for estrogenic compounds and previous studies have shown that tibolone protects brain cortical neurons in association with a reduction in reactive astrogliosis in a mouse model of traumatic brain injury. Since phagocytosis is a crucial component of the neuroprotective function exerted by astrocytes, in the present study, we have assessed whether tibolone regulates phagocytosis in primary astrocytes incubated with brain-derived cellular debris.

METHODS

Male and female astrocyte cell cultures were obtained from newborn (P0-P2) female and male Wistar rats. Astrocytic phagocytosis was first characterized using carboxylate beads, Escherichia coli particles, or brain-derived cellular debris. Then, the effect of tibolone on the phagocytosis of Cy3-conjugated cellular debris was quantified by measuring the intensity of Cy3 dye-emitted fluorescence in a given GFAP immunoreactive area. Before the phagocytosis assays, astrocytes were incubated with tibolone in the presence or absence of estrogen or androgen receptor antagonists or an inhibitor of the enzyme that synthesizes estradiol. The effect of tibolone on phagocytosis was analyzed under basal conditions and after inflammatory stimulation with lipopolysaccharide.

RESULTS

Tibolone stimulated phagocytosis of brain-derived cellular debris by male and female astrocytes, with the effect being more pronounced in females. The effect of tibolone in female astrocytes was blocked by a selective estrogen receptor β antagonist and by an androgen receptor antagonist. None of these antagonists affected tibolone-induced phagocytosis in male astrocytes. In addition, the inhibition of estradiol synthesis in the cultures enhanced the stimulatory effect of tibolone on phagocytosis in male astrocytes but blocked the effect of the steroid in female cells under basal conditions. However, after inflammatory stimulation, the inhibition of estradiol synthesis highly potentiated the stimulation of phagocytosis by tibolone, particularly in female astrocytes.

CONCLUSIONS

Tibolone exerts sex-specific regulation of phagocytosis in astrocytes of both sexes, both under basal conditions and after inflammatory stimulation.

Effects of Tibolone on the Central Nervous System: Clinical and Experimental Approaches

Hormone replacement therapy (HRT) increases the risk of endometrial and breast cancer. A strategy to reduce this incidence is the use of tibolone (TIB). The aim of this paper was to address the effects of TIB on the central nervous system (CNS). For the present review, MEDLINE (via PubMed), LILACS (via BIREME), Ovid Global Health, SCOPUS, Scielo, and PsycINFO (ProQuest Research Library) electronic databases were searched for the results of controlled clinical trials on peri- and postmenopausal women published from 1990 to September 2016. Also, this paper reviews experimental studies performed to analyze neuroprotective effects, cognitive deficits, neuroplasticity, oxidative stress, and stroke using TIB. Although there are few studies on the effect of this hormone in the CNS, it has been reported that TIB decreases lipid peroxidation levels and improves memory and learning. TIB has important neuroprotective effects that could prevent the risk of neurodegenerative diseases in postmenopausal women as well as the benefits of HRT in counteracting hot flashes, improving mood, and libido. Some reports have found that TIB delays cognitive impairment in various models of neuronal damage. It also modifies brain plasticity since it acts as an endocrine modulator regulating neurotransmitters, Tau phosphorylation, and decreasing neuronal death. Finally, its antioxidant effects have also been reported in different animal models.

Hysterectomy for benign disease: clinical practice guidelines from the French College of Obstetrics and Gynecology

OBJECTIVE

The objective of the study was to draw up French College of Obstetrics and Gynecology (CNGOF) clinical practice guidelines based on the best available evidence concerning hysterectomy for benign disease.

METHODS

Each recommendation for practice was allocated a grade, which depends on the level of evidence (clinical practice guidelines).

RESULTS

Hysterectomy should be performed by a high-volume surgeon (>10 hysterectomy procedures per year) (gradeC). Stimulant laxatives taken as a rectal enema are not recommended prior to hysterectomy (gradeC). It is recommended to carry out vaginal disinfection using povidone-iodine solution prior to hysterectomy (grade B). Antibiotic prophylaxis is recommended during hysterectomy, regardless of the surgical approach (grade B). The vaginal or laparoscopic approach is recommended for hysterectomy for benign disease (grade B), even if the uterus is large and/or the patient is obese (gradeC). The choice between these two surgical approaches depends on other parameters, such as the surgeon's experience, the mode of anesthesia, and organizational constraints (duration of surgery and medical economic factors). Vaginal hysterectomy is not contraindicated in nulliparous women (gradeC) or in women with previous cesarean section (gradeC). No specific hemostatic technique is recommended with a view to avoiding urinary tract injury (gradeC). In the absence of ovarian disease and a personal or family history of breast/ovarian carcinoma, the ovaries should be preserved in pre-menopausal women (grade B). Subtotal hysterectomy is not recommended with a view to reducing the risk of peri- or postoperative complications (grade B).

CONCLUSION

The application of these recommendations should minimize risks associated with hysterectomy.

Medical Therapies for Uterine Fibroids - A Systematic Review and Network Meta-Analysis of Randomised Controlled Trials

Background

Uterine fibroids are common, often symptomatic and a third of women need repeated time off work. Consequently 25% to 50% of women with fibroids receive surgical treatment, namely myomectomy or hysterectomy. Hysterectomy is the definitive treatment as fibroids are hormone dependent and frequently recurrent. Medical treatment aims to control symptoms in order to replace or delay surgery. This may improve the outcome of surgery and prevent recurrence.

Purpose

To determine whether any medical treatment can be recommended in the treatment of women with fibroids about to undergo surgery and in those for whom surgery is not planned based on currently available evidence.

Study Selection

Two authors independently identified randomised controlled trials (RCT) of all pharmacological treatments aimed at the treatment of fibroids from a list of references obtained by formal search of MEDLINE, EMBASE, Cochrane library, Science Citation Index, and ClinicalTrials.gov until December 2013.

Data Extraction

Two authors independently extracted data from identified studies.

Data Synthesis

A Bayesian network meta-analysis was performed following the National Institute for Health and Care Excellence—Decision Support Unit guidelines. Odds ratios, rate ratios, or mean differences with 95% credible intervals (CrI) were calculated.

Results and Limitations

A total of 75 RCT met the inclusion criteria, 47 of which were included in the network meta-analysis. The overall quality of evidence was very low. The network meta-analysis showed differing results for different outcomes.

Conclusions

There is currently insufficient evidence to recommend any medical treatment in the management of fibroids. Certain treatments have future promise however further, well designed RCTs are needed.

Add-back therapy with GnRH analogues for uterine fibroids

BACKGROUND

Uterine fibroids (also known as leiomyomas) are the most common benign pelvic tumours among women. They may be asymptomatic, or may be associated with pelvic symptoms such as bleeding and pain. Medical treatment of this condition is limited and gonadotropin-releasing hormone (GnRH) analogues are the most effective agents. Long-term treatment with such agents, however, is restricted due to their adverse effects. The addition of other medications during treatment with GnRH analogues, a strategy known as add-back therapy, may limit these side effects. There is concern, however, that add-back therapy may also limit the efficacy of the GnRH analogues and that it may not be able to completely prevent their adverse effects.

OBJECTIVES

To assess the short-term (within 12 months) effectiveness and safety of add-back therapy for women using GnRH analogues for uterine fibroids associated with excessive uterine bleeding, pelvic pain, or urinary symptoms.

SEARCH METHODS

We searched electronic databases including the Cochrane Menstrual Disorders and Subfertility Group (MDSG) Specialised Register, CENTRAL, MEDLINE, PubMed, EMBASE, LILACS, CINAHL, PsycINFO; and electronic registries of ongoing trials including ClinicalTrials.gov, Current Controlled Trials, World Health Organization (WHO) International Clinical Trials Registry Platform. All searches were from database inception to 16 June 2014.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that included women with uterine fibroids experiencing irregular or intense uterine bleeding, cyclic or non-cyclic pelvic pain, or urinary symptoms, and that compared treatment with a GnRH analogue plus add-back therapy versus a GnRH analogue alone or combined with placebo were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed the identified titles and abstracts for potentially eligible records. Two review authors reviewed eligible studies and independently extracted data. Two authors independently assessed the studies' risk of bias. They assessed the quality of the evidence using GRADE criteria.

MAIN RESULTS

Fourteen RCTs were included in the review. Data were extracted from 12 studies (622 women). The primary outcome was quality of life (QoL).Add-back therapy with medroxyprogesterone (MPA): no studies reported QoL or uterine bleeding. There was no evidence of effect in relation to bone mass (standardized mean difference (SMD) 0.38, 95% confidence interval (CI) -0.62 to 1.38, 1 study, 16 women, P = 0.45, low quality evidence) and MPA was associated with a larger uterine volume (mean difference (MD) 342.19 cm(3), 95% CI 77.58 to 606.80, 2 studies, 32 women, I(2) = 0%, low quality evidence).Tibolone: this was associated with a higher QoL but the estimate was imprecise and the effect could be clinically insignificant, small or large (SMD 0.47, 95% CI 0.09 to 0.85, 1 study, 110 women, P = 0.02, low quality evidence). It was also associated with a decreased loss of bone mass, which could be insignificant, small or moderate (SMD 0.36, 95% CI 0.03 to 0.7, 3 studies, 160 women, I(2) = 7%, moderate quality evidence). Tibolone may, however, have been associated with larger uterine volumes (MD 23.89 cm(3), 95% CI= 8.13 to 39.66, 6 studies, 365 women, I(2) = 0%, moderate quality evidence) and more uterine bleeding (results were not combined but three studies demonstrated greater bleeding with tibolone while two other studies demonstrated no bleeding in either group). Four studies (268 women; not pooled owing to extreme heterogeneity) reported a large benefit on vasomotor symptoms in the tibolone group.Raloxifene: there was no evidence of an effect on QoL (SMD 0.11, 95% CI -0.57 to 0.34, 1 study, 74 women, P = 0.62, low quality evidence), while there was a beneficial impact on bone mass (SMD 1.01, 95% CI 0.57 to 1.45, 1 study, 91 women, P < 0.00001, low quality evidence). There was no clear evidence of effect on uterine volume (MD 27.1 cm(3), 95% CI -17.94 to 72.14, 1 study, 91 women, P = 0.24, low quality evidence), uterine bleeding or severity of vasomotor symptoms (MD 0.2 hot flushes/day, 95% CI -0.34 to 0.74, 1 study, 91 women, P = 0.46, low quality evidence).Estriol: no studies reported QoL, uterine size, uterine bleeding or vasomotor symptoms. Add-back with estriol may have led to decreased loss of bone mass, from results of a single study (SMD 3.93, 95% CI 1.7 to 6.16, 1 study, 12 women, P = 0.0005, low quality evidence).Ipriflavone: no studies reported QoL, uterine size or uterine bleeding. Iproflavone was associated with decreased loss of bone mass in a single study (SMD 2.71, 95% CI 2.14 to 3.27, 1 study, 95 women, P < 0.00001, low quality evidence); there was no evidence of an effect on the rate of vasomotor symptoms (RR 0.67, 95% Cl 0.44 to 1.02, 1 study, 95 women, P = 0.06, low quality evidence).Conjugated estrogens: no studies reported QoL, uterine size, uterine bleeding or vasomotor symptoms. One study suggested that adding conjugated estrogens to GnRH analogues resulted in a larger decrease in uterine volume in the placebo group (MD 105.2 cm(3), 95% CI 27.65 to 182.75, 1 study, 27 women, P = 0.008, very low quality evidence).Nine of 12 studies were at high risk of bias in at least one domain, most commonly lack of blinding. All studies followed participants for a maximum of six months. This short-term follow-up is usually insufficient to observe any significant effect of the treatment on bone health (such as the occurrence of fractures), limiting the findings.

AUTHORS' CONCLUSIONS

There was low or moderate quality evidence that tibolone, raloxifene, estriol and ipriflavone help to preserve bone density and that MPA and tibolone may reduce vasomotor symptoms. Larger uterine volume was an adverse effect associated with some add-back therapies (MPA, tibolone and conjugated estrogens). For other comparisons, outcomes of interest were not reported or study findings were inconclusive.

Effects of inhibition of gonadotropin releasing hormone secretion on the response to novel objects in young male and female sheep

This study investigated the actions of blocking the GnRH receptor using a specific agonist on the response of male and female sheep to a novel object placed in their pen. The study is part of a series performed on 46 same sex twin animals. One of the pair received a subcutaneous implant of the GnRH agonist Goserelin acetate every four weeks while the other remained untreated. Implantation began immediately prior to puberty; at 8 weeks in the males and 28 weeks in the females (as timing of puberty is sex specific). To determine the effects of agonist treatment on the reproductive axis blood samples were collected for measurement of testosterone in the males and progesterone in the females. In addition the volume of the scrotum was determined. The present study aimed to determine whether there are sexually differentiated behavioural responses to a novel object at different stages of brain development (8, 28 and 48 weeks of age) and whether these responses are altered by GnRHa treatment. Approach behaviour towards and interactions with the novel object were monitored as was the number of vocalisations per unit time during the test period. GnRHa treatment suppressed testosterone concentrations and testicular growth in the males and progesterone release in the females. Sheep vocalised significantly more prior to weaning (8 weeks of age) than post weaning (28 and 48 weeks of age) suggesting stress on separation from their dams. Our current study shows that males are more likely to leave their conspecifics to approach a novel object than females. As this behaviour was not altered by suppression of the reproductive axis we suggest that, although sex differences are more obviously expressed in the phenotype after puberty, these may be developed during adolescence but not primarily altered during puberty by sex hormones.

Development of psychophysiological motoric reactivity is influenced by peripubertal pharmacological inhibition of gonadotropin releasing hormone action--results of an ovine model

This study reports the effects of peripubertal GnRH receptor inactivation on development of psychophysiological motoric reactivity (PMR; sometimes also called emotional reactivity), plasma cortisol concentrations and the relationship between plasma cortisol and PMR in male and female sheep. The study formed part of a larger trial and utilised 46 same sex twins. One twin remained untreated (control) while the other received a subcutaneous GnRH agonist (GnRHa Goserelin-Acetate) implant every 4th week, beginning at 8 and 28 weeks of age, in males and females, respectively (different, due to sex specific age of puberty). PMR, a measure of an animals' response to social isolation, was measured over a two minute period at 8, 28 and 48 weeks of age, using a three axis accelerometer. During the test period vocalisation rate was recorded. Cortisol was assayed in blood samples collected on a single day when animals were 40 weeks of age. PMR and vocalisation rate were significantly higher in females than males at all ages tested. At 28 weeks of age (20 weeks treatment) PMR was increased in treated males to the level seen in control females, by 48 weeks of age treated males' PMR was significantly less than controls. In females, 20 weeks of GnRHa treatment (28-48 weeks of age) was not associated with differences in PMR. Cortisol concentrations were significantly higher in females than males but were not affected by treatment. Plasma cortisol concentrations were positively correlated with PMR; this relationship being driven by the treated animals in both sexes. The results demonstrate that PMR is sexually dimorphic and cortisol dependent in sheep from at least 8 weeks of age. Importantly, they also demonstrate that long-term treatment of males with a GnRH agonist results in changes in age-dependent development of PMR.

Medical treatment of uterine leiomyoma

Uterine leiomyomas (also called myomata or fibroids) are the most common gynecologic tumors in the United States. The prevalence of leiomyomas is at least 3 to 4 times higher among African American women than in white women. Pathologically, uterine leiomyomas are benign tumors that arise in any part of the uterus under the influence of local growth factors and sex hormones, such as estrogen and progesterone. These common tumors cause significant morbidity for women and they are considered to be the most common indication for hysterectomy in the world; they are also associated with a substantial economic impact on health care systems that amounts to approximately $2.2 billion/year in the United States alone. Uterine myomas cause several reproductive problems such as heavy or abnormal uterine bleeding, pelvic pressure, infertility, and several obstetrical complications including miscarriage and preterm labor. Surgery has traditionally been the gold standard for the treatment of uterine leiomyomas and has typically consisted of either hysterectomy or myomectomy. In recent years, a few clinical trials have evaluated the efficacy of orally administered medications for the management of leiomyoma-related symptoms. In the present review, we will discuss these promising medical treatments in further detail.

Chronic administration of tibolone modulates anxiety-like behavior and enhances cognitive performance in ovariectomized rats

Hormone replacement therapy (HRT) may be prescribed to prevent the symptoms of menopause. This therapy may include estrogenic and/or progestin components and may increase the incidence of endometrial and breast cancers. Tibolone (TIB), which is also made up of estrogen and progestin components, is often used to reduce the impact of HRT. However, the effect of TIB on the processes of learning, memory and anxiety has yet to be fully elucidated. The aim of this study was to evaluate the long-term effect on learning, memory processes and anxiety in ovariectomized rats caused by different doses of TIB (0 mg/kg, 0.01 mg/kg, 0.1 mg/kg 1.0 mg/kg and 10 mg/kg, administered daily via the oral route for 18 weeks). Two behavioral animal models, the autoshaping and T maze models were employed. The concentrations of acetyl choline transferase (ChAT) and tryptophan hydroxylase (TPH) in the hippocampus were directly measured by Western blot. No significant changes were observed in the autoshaping model and spontaneous activity test. In the T maze, increased latency was observed with TIB doses of 1 and 10 mg/kg compared to the vehicle. We observed that the ChAT content decreased with increasing doses of TIB, whereas TPH content increased with doses of 1 and 10 mg/kg of TIB. These data indicate that high doses of TIB improved emotional learning, which may be related to the modulation of the cholinergic and serotonergic systems by TIB.

Current and emerging treatments for uterine myoma - an update

Uterine myomas, the most common benign, solid, pelvic tumors in women, occur in 20%–40% of women in their reproductive years and form the most common indication for hysterectomy. Various factors affect the choice of the best treatment modality for a given patient. Asymptomatic myomas may be managed by reassurance and careful follow up. Medical therapy should be tried as a first line of treatment for symptomatic myomas, while surgical treatment should be reserved only for appropriate indications. Hysterectomy has its place in myoma management in its definitiveness. However, myomectomy, rather than hysterectomy, should be performed when subsequent childbearing is a consideration. Preoperative gonadotropin-releasing hormone analog treatment before myomectomy decreases the size and vascularity of the myoma but may render the capsule more fibrous and difficult to resect. Uterine artery embolization is an effective standard alternative for women with large symptomatic myomas who are poor surgical risks or wish to avoid major surgery. Its effects on future fertility need further evaluation in larger studies. Serial follow-up without surgery for growth and/or development of symptoms is advisable for asymptomatic women, particularly those approaching menopause. The present article is incorporated with multiple clear clinical photographs and simplified elaboration of the available management options for these tumors of uterine smooth muscle to facilitate clear understanding.

Effects of neonatal flutamide treatment on hippocampal neurogenesis and synaptogenesis correlate with depression-like behaviors in preadolescent male rats

The prevalence of major depressive disorder (MDD) in adult men is roughly half that of women. Clinical evidence supports a protective effect of androgens against depressive disorders in men. The developing brain is subject to androgen exposure but a potential role for this in depression during adulthood has not been considered. In order to explore this question we treated newborn male rat pups with the androgen receptor antagonist flutamide to block endogenous androgen action and then conducted behavioral tests prior to puberty. Depression-like behaviors were assessed with the Forced Swim Test (FST) and the Sucrose Preference Test (SPT), and anxiety-like behaviors were assessed with the Open Field Test (OFT) and the Novelty-Suppressed Feeding Test (NSFT). Compared to the vehicle-treated controls, neonatal-flutamide treatment caused a significant increase in depression-like behaviors in preadolescent male rats but did not cause any significant difference in anxiety-like behaviors. In separate experiments, male pups with and without flutamide treatment were injected with 5-bromo-2'-deoxyuridine-5'-monophosphate (BrdU) from postnatal day (PND) 1 to 4 to label newly produced cells or the hippocampi were Golgi-Cox imbedded and pyramidal neurons visualized. Three lines of evidence indicate neonatal flutamide treatment inhibits hippocampal neurogenesis and neuronal dendritic spine formation in preadolescent male rats. Compared to vehicle controls, flutamide treatment significantly decreased (1) the number of microtubule-associated protein-2+ (MAP-2) neurons in the CA1 region, (2) the number of MAP-2+ neurons in the dentate gyrus (DG) region of the hippocampus, and (3) the density of dendritic spines of pyramidal neurons in the CA1 region. However, there was no effect of flutamide treatment on the number of glial fibrillary acidic protein (GFAP)+ or GFAP+/BrdU+ cells in the hippocampus. This study suggests that the organizational effect of androgen-induced hippocampal neurogenesis is antidepressant.

Chronic administration of androgens with actions at estrogen receptor beta have anti-anxiety and cognitive-enhancing effects in male rats

Androgen levels decline with aging. Some androgens may exert anti-anxiety and cognitive-enhancing effects; however, determining which androgens have anxiolytic-like and/or mnemonic effects is of interest given the different mechanisms that may underlie some of their effects. For example, the 5 alpha-reduced metabolite of testosterone (T), dihydrotesterone, can be further converted to 5 alpha-androstane,17beta-diol-3 alpha-diol (3 alpha-diol) and 5 alpha-androstane,17beta-diol-3beta-diol (3beta-diol), both of which bind with high affinity to the beta isomer of the intracellular estrogen receptor beta (ER beta). However, androsterone, another metabolite of T, does not bind well to ER beta. To investigate the effects of T metabolites, male rats were subjected to gonadectomy then implanted with silastic capsules of 3 alpha-diol, 3beta-diol, androsterone, or oil control. After recovery, the rats were tested in elevated plus maze (EPM), light/dark transition (LD), and Morris water maze (MWM). 3 alpha-diol both decreased anxiety-like behavior in the EPM and LD, and increased cognition in MWM, while 3beta-diol improved cognition in MWM, but had no effects on anxiety behavior, compared to vehicle or androsterone. These data suggest that the actions of 3 alpha-diol and 3beta-diol at ER beta may be responsible for some of testosterone's anti-anxiety and cognitive-enhancing effects.

Chronic administration of androgens with actions at estrogen receptor beta have anti-anxiety and cognitive-enhancing effects in male rats

Androgen levels decline with aging. Some androgens may exert anti-anxiety and cognitive-enhancing effects; however, determining which androgens have anxiolytic-like and/or mnemonic effects is of interest given the different mechanisms that may underlie some of their effects. For example, the 5 alpha-reduced metabolite of testosterone (T), dihydrotesterone, can be further converted to 5 alpha-androstane,17beta-diol-3 alpha-diol (3 alpha-diol) and 5 alpha-androstane,17beta-diol-3beta-diol (3beta-diol), both of which bind with high affinity to the beta isomer of the intracellular estrogen receptor beta (ER beta). However, androsterone, another metabolite of T, does not bind well to ER beta. To investigate the effects of T metabolites, male rats were subjected to gonadectomy then implanted with silastic capsules of 3 alpha-diol, 3beta-diol, androsterone, or oil control. After recovery, the rats were tested in elevated plus maze (EPM), light/dark transition (LD), and Morris water maze (MWM). 3 alpha-diol both decreased anxiety-like behavior in the EPM and LD, and increased cognition in MWM, while 3beta-diol improved cognition in MWM, but had no effects on anxiety behavior, compared to vehicle or androsterone. These data suggest that the actions of 3 alpha-diol and 3beta-diol at ER beta may be responsible for some of testosterone's anti-anxiety and cognitive-enhancing effects.