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857 result(s) for "Testosterone - antagonists "
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Efficacy and safety of triptorelin 6-month formulation in patients with central precocious puberty
Triptorelin is an established treatment for central precocious puberty (CPP) as 1- and 3-month formulations. The current triptorelin 22.5 mg 6-month formulation is approved for prostate cancer therapy. This is the first study in patients with CPP. The efficacy and safety of the triptorelin 6-month formulation in CPP were investigated. The primary objective was to evaluate the efficacy in achieving luteinizing hormone (LH) suppression to pre-pubertal levels at month 6. This was an international, non-comparative phase III study over 48 weeks. Eighteen medical centers in the US, Chile and Mexico participated. Forty-four treatment naïve patients (39 girls and five boys) aged at treatment start 2–8 years for girls and 2–9 years for boys with an advancement of bone age over chronological age ≥1 year were to be included. Triptorelin was administered im twice at an interval of 24 weeks. LH, follicle stimulating hormone (FSH) (basal and stimulated), estradiol (girls), testosterone (boys), auxological parameters, clinical signs of puberty and safety were assessed. Forty-one patients (93.2%) showed pre-pubertal LH levels (stimulated LH ≤5 IU/L) at month 6 and maintained LH suppression through month 12. The percentage of patients with LH suppression exceeded 93% at each time point and reached 97.7% at month 12. No unexpected drug-related adverse events were reported. The triptorelin 6-month formulation was safe and effective in suppressing the pituitary-gonadal axis in children with CPP. The extended injection interval may improve compliance and increase comfort in the management of CPP.
Can exercise ameliorate treatment toxicity during the initial phase of testosterone deprivation in prostate cancer patients? Is this more effective than delayed rehabilitation?
Background There has been substantial increase in use of androgen deprivation therapy as adjuvant management of prostate cancer. However, this leads to a range of musculoskeletal toxicities including reduced bone mass and increased skeletal fractures compounded with rapid metabolic alterations, including increased body fat, reduced lean mass, insulin resistance and negative lipoprotein profile, increased incidence of cardiovascular and metabolic morbidity, greater distress and reduced quality of life. Numerous research studies have demonstrated certain exercise prescriptions to be effective at preventing or even reversing these treatment toxicities. However, all interventions to date have been of rehabilitative intent being implemented after a minimum of 3 months since initiation of androgen deprivation, by which time considerable physical and psychological health problems have manifested. The pressing question is whether it is more efficacious to commence exercise therapy at the same time as initiating androgen deprivation, so treatment induced adverse effects can be immediately attenuated or indeed prevented. Methods/design We are proposing a multi-site randomized controlled trial with partial crossover to examine the effects of timing of exercise implementation (immediate or delayed) on preserving long-term skeletal health, reversing short- and long-term metabolic and cardiovascular risk factors, and supporting mental health in men receiving androgen deprivation therapy. 124 men who are about to initiate androgen deprivation for prostate cancer will be randomized to immediate or delayed groups. Immediate will commence a 6-month exercise program within 7–10 days of their first dose. Delayed will receive usual care for 6 months and then commence the exercise program for 6 months (partial cross-over). Immediate will be free to adopt the lifestyle of their choosing following the initial 6-month intervention. Measurements for primary and secondary endpoints will take place at baseline, 6 months and 12 months. Discussion This project is unique as it explores a fundamental question of when exercise implementation will be of most benefit and addresses both physical and psychological consequences of androgen deprivation initiation. The final outcome may be adjunct treatment which will reduce if not prevent the toxicities of androgen deprivation, ultimately resulting in reduced morbidity and mortality for men with prostate cancer. Trial registration ACTRN12612000097842
How does hormone transition in transgender women change body composition, muscle strength and haemoglobin? Systematic review with a focus on the implications for sport participation
ObjectivesWe systemically reviewed the literature to assess how long-term testosterone suppressing gender-affirming hormone therapy influenced lean body mass (LBM), muscular area, muscular strength and haemoglobin (Hgb)/haematocrit (HCT).DesignSystematic review.Data sourcesFour databases (BioMed Central, PubMed, Scopus and Web of Science) were searched in April 2020 for papers from 1999 to 2020.Eligibility criteria for selecting studiesEligible studies were those that measured at least one of the variables of interest, included transwomen and were written in English.ResultsTwenty-four studies were identified and reviewed. Transwomen experienced significant decreases in all parameters measured, with different time courses noted. After 4 months of hormone therapy, transwomen have Hgb/HCT levels equivalent to those of cisgender women. After 12 months of hormone therapy, significant decreases in measures of strength, LBM and muscle area are observed. The effects of longer duration therapy (36 months) in eliciting further decrements in these measures are unclear due to paucity of data. Notwithstanding, values for strength, LBM and muscle area in transwomen remain above those of cisgender women, even after 36 months of hormone therapy.ConclusionIn transwomen, hormone therapy rapidly reduces Hgb to levels seen in cisgender women. In contrast, hormone therapy decreases strength, LBM and muscle area, yet values remain above that observed in cisgender women, even after 36 months. These findings suggest that strength may be well preserved in transwomen during the first 3 years of hormone therapy.
Effects of short‐term sex steroid suppression on dietary fat storage patterns in healthy males
Hypogonadism in males is associated with increased body fat and altered postprandial metabolism, but mechanisms remain poorly understood. Using a cross‐over study design, we investigated the effects of short‐term sex hormone suppression with or without testosterone add‐back on postprandial metabolism and the fate of dietary fat. Eleven healthy males (age: 29 ± 4.5 year; BMI: 26.3 ± 2.1 kg/m2) completed two 7‐day study phases during which hormone levels were altered pharmacologically to produce a low sex hormone condition (gonadotropin releasing hormone antagonist, aromatase inhibitor, and placebo gel) or a testosterone add‐back condition (testosterone gel). Following 7 days of therapy, subjects were administered an inpatient test meal containing 50 μCi of [1‐14C] oleic acid. Plasma samples were collected hourly for 5 h to assess postprandial responses. Energy metabolism (indirect calorimetry) and dietary fat oxidation (14CO2 in breath) were assessed at 1, 3, 5, 13.5, and 24 h following the test meal. Abdominal and femoral adipose biopsies were taken 24 h after the test meal to determine uptake of the labeled lipid. Postprandial glucose, insulin, free‐fatty acid, and triglyceride responses were not different between conditions (P > 0.05). Whole‐body energy metabolism was also not different between conditions at any time point (P > 0.05). Dietary fat oxidation trended lower (P = 0.12) and the relative uptake of 14C labeled lipid into femoral adipose tissue was greater (P = 0.03) in the low hormone condition. Short‐term hormone suppression did not affect energy expenditure or postprandial metabolism, but contributed to greater relative storage of dietary fat in the femoral depot. ClinicalTrials.gov Identifier: NCT03289559. Hypogonadism in males is associated with increased adiposity and altered dietary fat metabolism, but the specific role of low testosterone in these age‐related changes is not well understood. Using a pharmacological model of gonadal aging in young men (GnRH antagonist ± testosterone), we found that low testosterone was not associated with altered energy expenditure, fuel utilization, or postprandial metabolism. However, low testosterone did contribute to greater storage of dietary fat in the femoral depot.
Androgen receptor signalling impairs docetaxel efficacy in castration-resistant prostate cancer
Androgen receptor (AR) signalling drives neoplastic growth and therapy resistance in prostate cancer. Recent clinical data show that docetaxel combined with androgen deprivation therapy improves outcome in hormone-sensitive disease. We studied whether testosterone and AR signalling interferes with docetaxel treatment efficacy in castration-resistant prostate cancer (CRPC). We found that testosterone supplementation significantly impaired docetaxel tumour accumulation in a CRPC model, resulting in decreased tubulin stabilisation and antitumour activity. Furthermore, testosterone competed with docetaxel for uptake by the drug transporter OATP1B3. Irrespective of docetaxel-induced tubulin stabilisation, AR signalling by testosterone counteracted docetaxel efficacy. AR-pathway activation could also reverse long-term tumour regression by docetaxel treatment in vivo. These results indicate that to optimise docetaxel efficacy, androgen levels and AR signalling need to be suppressed. This study lends evidence for continued maximum suppression of AR signalling by combining targeted therapeutics with docetaxel in CRPC.
11-Keto-testosterone and Other Androgens of Adrenal Origin
The adrenal glands produce significant amounts of steroid hormones and their metabolites, with various levels of androgenic activities. Until recently, the androgenic potency of these adrenal-derived compounds were not well known, but some recent studies have shown that the production of 11-oxo- and 11β-hydroxy-derived testosterone and dihydrotestosterone evidently have high androgenic activity. This fact has clinical importance, for instance, in various types of congenital adrenal hyperplasia with androgenization or polycystic ovarian syndrome, and laboratory determinations of these substances could help to better evaluate the total androgen pressure in patients with these disorders. Another area of concern is the treatment of prostate cancer with androgen deprivation, which loses effectiveness after a certain time. The concurrent blocking of the secretion of adrenal C19-steroids, whether using corticoids or adrenostatics, could increase the effectiveness of androgen-deprivation therapy.
Neuropsychiatric and Behavioral Involvement in AAS Abusers. A Literature Review
Background and Objectives: Anabolic androgenic steroids (AASs) are a complex group of molecules that include both steroidal androgens and synthetic compounds, derived from testosterone. AASs are commonly used to support pharmacological therapy in cases of primary or secondary hypogonadism, major burns, and neoplastic cachexia. Their prolonged and supra-physiological consumption can provoke several adverse effects on various organs and systems. Among these, the physiopathological mechanisms that induce neuropsychiatric disorders related to AAS abuse are poorly known. For this reason, the proposed review aims to retrace the pathway of action of testosterone to focus on the effects on the central nervous system and specifically highlight the effects of AASs on neuropsychiatric and behavioral functions, as well as on lifestyle. Materials and Methods: This review was conducted using PubMed and Google Scholar databases. On these database websites, we searched for articles from 1 January 1980 to March 2019 using the key terms: “AAS,” “Anabolic Androgenic Steroids,” “brain,” and “neurology.” Results: The use of AASs through self-administration yields circulating androgens levels, inducing neuron apoptosis, which is linked to thinner cortex and, in general, less cortical volume. The same alterations affect the putamen. These differences were more evident when correlated with longer use. From a functional point of view, prolonged AAS consumption seemed to be related to lower connectivity between amygdala and frontal, striatal, limbic, hippocampal and visual cortical areas. On the other hand, AAS use seems to negatively condition the positive effects of the sport exercise, reducing its important anti-apoptotic and pro-proliferative functions on the hippocampus, implicated in anxiolytic control. Conclusion: This review clarifies the major aspects of the side effects related to AAS use/abuse highlighting the complex mechanisms on neuropsychiatric and cognitive pathological alterations and also the emotional and behavioral dysfunctions.
The Footprints of Oxidative Stress and Mitochondrial Impairment in Arsenic Trioxide-Induced Testosterone Release Suppression in Pubertal and Mature F1-Male Balb/c Mice via the Downregulation of 3β-HSD, 17β-HSD, and CYP11a Expression
Exposure to arsenic (AS) causes abnormalities in the reproductive system; however, the precise cellular pathway of AS toxicity on steroidogenesis in developing F1-male mice has not been clearly defined. In this study, paternal mice were treated with arsenic trioxide (As 2 O 3 ; 0, 0.2, 2, and 20 ppm in drinking water) from 5 weeks before mating until weaning and continued for male offspring from weaning until maturity (in vivo). Additionally, Leydig cells (LCs) were isolated from the testes of sacrificed F1-intact mature male mice and incubated with As 2 O 3 (0, 1, 10, and 100 μM) for 48 h (in vitro). Biomarkers of mitochondrial impairment, oxidative stress, and several steroidogenic genes, including the steroidogenic acute regulatory (StAR) protein, cytochrome P450 side-chain cleaving enzyme (P450scc; Cyp11a), 3β-hydroxysteroid dehydrogenase (3β-HSD), and 17β-hydroxysteroid dehydrogenase (17β-HSD), were evaluated. High doses of As 2 O 3 interrupted testosterone (T) biosynthesis and T-related gene expression in these experimental models. Altogether, overconsumption of As 2 O 3 can cause testicular and LC toxicity through mitochondrial-related pathways and oxidative stress indices as well as downregulation of androgenic-related genes in mice and isolated LCs. These results could lead to the development of preventive/therapeutic procedures against As 2 O 3 -induced reproductive toxicity. Graphical Abstract Mohammad Mehdi Ommati and Reza Heidari contributed equally to this study.
Testosterone and oxidative stress: the oxidation handicap hypothesis
Secondary sexual traits (SST) are usually thought to have evolved as honest signals of individual quality during mate choice. Honesty of SST is guaranteed by the cost of producing/maintaining them. In males, the expression of many SST is testosterone-dependent. The immunocompetence handicap hypothesis has been proposed as a possible mechanism ensuring honesty of SST on the basis that testosterone, in addition to its effect on sexual signals, also has an immunosuppressive effect. The immunocompetence handicap hypothesis has received mixed support. However, the cost of testosterone-based signalling is not limited to immunosuppression and might involve other physiological functions such as the antioxidant machinery. Here, we tested the hypothesis that testosterone depresses resistance to oxidative stress in a species with a testosterone-dependent sexual signal, the zebra finch. Male zebra finches received subcutaneous implants filled with flutamide (an anti-androgen) or testosterone, or kept empty (control). In agreement with the prediction, we found that red blood cell resistance to a free radical attack was the highest in males implanted with flutamide and the lowest in males implanted with testosterone. We also found that cell-mediated immune response was depressed in testosterone-treated birds, supporting the immunocompetence handicap hypothesis. The recent finding that red blood cell resistance to free radicals is negatively associated with mortality in this species suggests that benefits of sexual signalling might trade against the costs derived from oxidation.
HMGB1/NF-κB Axis, IL-8, and Cuproptosis Contribute to Cisplatin-Induced Testicular Injury: Protective Potential Effect of Thymol
Background: Cisplatin (CP) use is associated with testicular toxicity. Cuproptosis-related genes are associated with dysfunctional spermatogenesis. Additionally, the HMGB1/NF-κB axis has been involved in cuproptosis-mediated inflammation. The aim of the current study was to investigate the effect of CP toxicity on the HMGB1/NF-κB axis and cuproptosis in the rat testis. The effect of thymol was also explored. Methods: Four groups of male Wistar rats were used: control, thymol (60 mg/kg P.O. daily for 2 weeks), CP (8 mg/kg i.p single injection), and CP+thymol. Results: CP induced a significant decrease in serum testosterone and LH. CP-induced oxidative stress was evident by the modulation of oxidative stress markers. The expressions of IL-8, NF-κB, and HMGB1 were induced by CP treatment, accompanied by increased expression of cuproptosis genes, including SLC31A1, FDX1, and DLAT. On the other hand, thymol antagonized CP testicular injury. Thymol’s effect was associated with reduced expressions of IL-8, NF-κB, HMGB1, and cuproptosis markers. Conclusions: Collectively, this study provides evidence of the possible potential role of the HMGB1/NF-κB axis and cuproptosis in CP-induced testicular injury and illustrates the protective effects of thymol against testicular damage, which are attributed, at least in part, to blunting HMGB1 and cuproptosis-related genes expression.