3,299 research outputs found

    Environmental concentrations of anti-androgenic pharmaceuticals do not impact sexual disruption in fish alone or in combination with steroid oestrogens

    Get PDF
    This article has been made available through the Brunel Open Access Publishing Fund.Sexual disruption in wild fish has been linked to the contamination of river systems with steroid oestrogens, including the pharmaceutical 17α-ethinylestradiol, originating from domestic wastewaters. As analytical chemistry has advanced, more compounds derived from the human usage of pharmaceuticals have been identified in the environment and questions have arisen as to whether these additional pharmaceuticals may also impact sexual disruption in fish. Indeed, pharmaceutical anti-androgens have been shown to induce such effects under laboratory conditions. These are of particular interest since anti-androgenic biological activity has been identified in the aquatic environment and is potentially implicated in sexual disruption alone and in combination with steroid oestrogens. Consequently, predictive modelling was employed to determine the concentrations of two anti-androgenic human pharmaceuticals, bicalutamide and cyproterone acetate, in UK sewage effluents and river catchments and their combined impacts on sexual disruption were then assessed in two fish models. Crucially, fish were also exposed to the anti-androgens in combination with steroid oestrogens to determine whether they had any additional impact on oestrogen induced feminisation. Modelling predicted that the anti-androgenic pharmaceuticals were likely to be widespread in UK river catchments. However, their concentrations were not sufficient to induce significant responses in plasma vitellogenin concentrations, secondary sexual characteristics or gross indices in male fathead minnow or intersex in Japanese medaka alone or in combination with steroid oestrogens. However, environmentally relevant mixtures of oestrone, 17ÎČ-oestradiol and 17α-ethinylestradiol did induce vitellogenin and intersex, supporting their role in sexual disruption in wild fish populations. Unexpectedly, a male dominated sex ratio (100% in controls) was induced in medaka and the potential cause and implications are briefly discussed, highlighting the potential of non-chemical modes of action on this endpoint

    Low estrogen doses normalize testosterone and estradiol levels to the female range in transgender women

    Get PDF
    OBJECTIVE: The ideal dosage of cross-sex hormones remains unknown. The aim of this study was to evaluate the luteinizing hormone, follicle-stimulating hormone, testosterone, estradiol and prolactin levels after low-dose estrogen therapy with or without cyproterone acetate in transgender women. METHODS: The serum hormone and biochemical profiles of 51 transgender women were evaluated before gonadectomy. Hormone therapy consisted of conjugated equine estrogen alone or combined with cyproterone acetate. The daily dose of conjugated equine estrogen was 0.625 mg in 41 subjects and 1.25 mg in 10 subjects, and the daily dose of cyproterone acetate was 50 mg in 42 subjects and 100 mg in one subject. RESULTS: Estrogen-only therapy reduced the testosterone, luteinizing hormone and follicle-stimulating hormone levels from 731.5 to 18 ng/dL, 6.3 to 1.1 U/L and 9.6 to 1.5 U/L, respectively. Estrogen plus cyproterone acetate reduced the testosterone, luteinizing hormone and follicle-stimulating hormone levels from 750 to 21 ng/dL, 6.8 to 0.6 U/L and 10 to 1.0 U/L, respectively. The serum levels of luteinizing hormone, follicle-stimulating hormone, testosterone, estradiol and prolactin in the patients treated with estrogen alone and estrogen plus cyproterone acetate were not significantly different. The group receiving estrogen plus cyproterone acetate had significantly higher levels of gamma-glutamyltransferase than the group receiving estrogen alone. No significant differences in the other biochemical parameters were evident between the patients receiving estrogen alone and estrogen plus cyproterone acetate. CONCLUSION: In our sample of transgender women, lower estrogen doses than those usually prescribed for these subjects were able to adjust the testosterone and estradiol levels to the physiological female range, thus avoiding high estrogen doses and their multiple associated side effects

    Treatment of Girls and Boys with McCune-Albright Syndrome with Precocious Puberty - Update 2017

    Get PDF
    The most common endocrinopathy associated with McCune-Albright Syndrome (MAS) is peripheral precocious puberty (PP) which occurs far more often in girls than in boys. We will discuss the latest advancements in the treatment of precocious puberty in MAS that have been achieved during the past 10 years. However, due to the rarity of the condition and the heterogeneity of the disease, research in this field is limited particularly in regards to treatment in boys. In girls, a period of watchful waiting is recommended prior to initiating therapy due to extreme variability in the clinical course. This article will review in detail current pharmacologic treatment in girls, which typically consists of either inhibiting estrogen production or blocking estrogen action at the level of the end-organ. The two treatments with the most evidence at this time are Tamoxifen (which is an estrogen receptor modulator) and Letrozole (which is a 3rd generation aromatase inhibitor). This article will also review the current treatment strategies in boys which typically include using an androgen receptor blocker and an aromatase inhibitor. Due to the rarity of the condition, large multicenter collaborative studies are needed to further investigate efficacy and safety with the goal of establishing the gold standard for treatment of PP in children with MAS

    Stimulatory effects of antiandrogens on LNCaP human prostate tumor cell growth, EGF-receptor level and acid phosphatase secretion

    Get PDF
    Abstract LNCaP cells (derived from a lymph node carcinoma of the human prostate) show androgen responsive growth. Progestagens, estradiol and antiandrogens competed with androgens for binding to the androgen receptor in the cells to a higher extent than in other androgen-sensitive systems. Optimal growth (3–4 fold increase in DNA content of 6 day cell cultures vs controls) was observed after addition of the synthetic androgen R1881 (0.1 nM). Both steroidal and non-steroidal antiandrogens did not suppress the androgen responsive growth. At a concentration of 10 nM cyproterone acetate or 100 nM RU 23908, growth was even stimulated to an extent comparable to that observed after addition of androgen. Cyproterone acetate and RU 23908 also increased the number of epidermal growth factor receptors expressed at the cell surface to a comparable level as did the androgen. Like androgens, cyproterone acetate, RU 23908 or estradiol stimulated the secretion per cell of prostate specific acid phosphatase in the culture fluid. In conclusion, antiandrogens can exert striking stimulatory effects on the proliferation of LNCaP cells probably due to a defective androgen receptor system. It is discussed that comparable changes in the specificity of the androgen receptor in prostate cancer cells may give these cells an advantage in growth rate and may contribute to development of tumors characterized as hormone independent

    Efficacy Of Cyproterone Acetate And Drosperinone Containing Cocps In Treatment Of Hirsutism In Patients With PCOS

    Get PDF
    Introduction: Hirsutism is a condition characterized by excess hair growth on the face, chest, and/or back in women and it is often caused by an imbalance of hormones, such as androgens. OCPs prove to be effective in reducing hirsutism in patients with PCOS by inhibiting the production of androgens and decreasing the activity of androgen receptors. OCPs may have additional benefits for patients with PCOS, such as regulating menstrual cycles, improving fertility, and reducing the risk of endometrial cancer. However, OCPs may not be suitable for all women with PCOS. Methods: The study was conducted to investigate the effectiveness of these OCPs in reducing hirsutism in PCOS patients. In the study, 80 participants were included, 40 in the intervention group and 40 in the control group. The intervention group received a combination oral contraceptive pill containing cyproterone acetate and drosperinone (COCP) for a period of 6 months, while the control group received a placebo. Hirsutism was assessed at baseline and at the end of the 6-month treatment period using the Ferriman-Gallwey score. The primary outcome measure was the change in Ferriman-Gallwey score from baseline to the end of the treatment period. Results: The study found that OCPs containing cyproterone acetate and drosperinone were more effective in reducing hirsutism in patients with PCOS compared to OCPs containing levonorgestrel. Conclusion: It is important to note that OCPs may not be appropriate for all women with PCOS, therefore it's crucial to explore the risks and advantages with a healthcare professional before beginning therapy

    Deoxyribonucleic acid-binding ability of androgen receptors in whole cells: implications for the actions of androgens and antiandrogens

    Get PDF
    In whole cells, the effects of several androgens and antiandrogens on the in the induction of DNA binding for the human wild-type androgen receptor (AR) and a mutant receptor ARL (LNCaP mutation; codon 868, Thr to Ala) were examined and related to the transcription activation ability of these receptors. To study DNA binding, an AR expression vector was cotransfected in Chinese hamster ovary cells with a promoter interference plasmid cytomegalovirus-(androgen-responsive element)3-luciferase, containing one or more androgen-responsive elements between the TATA box of the cytomegalovirus promoter and the start site of luciferase gene transcription. Expression levels of the AR are up-regulated by some agonists, but receptor expression levels are comparable for all antiandrogens studied. In the presence of androgens, the wild-type AR is able to reduce promoter activity of the cytomegalovirus-(androgen-responsive element)3-luciferase plasmid, indicating androgen-dependent DNA binding of the AR. The full antagonists hydroxyflutamide, ICI 176.334, and RU 23908 block AR binding to DNA. The antagonists cyproterone acetate and RU 38486 induce approximately 50% of the DNA binding found for androgens. In a transcription activation assay, the RU 38646-bound receptor was almost inactive, and the receptor complexed with cyproterone acetate showed partial agonistic activity. Interaction of the antagonists cyproterone acetate, hydroxyflutamide, and RU 23908 with the mutant receptor ARL resulted in both DNA-bound and a transcriptionally active receptor. In conclusion, transformation of the AR to a DNA-binding state in whole cells is blocked by several antiandrogens. Furthermore, studies with the antiandrogens cyproterone acetate and RU 38486 show that DNA binding alone is not sufficient to accomplish full transcriptional activity. Full activity requires additional changes, presumably in the protein structure of the receptor

    Antiandrogens Act as Selective Androgen Receptor Modulators at the Proteome Level in Prostate Cancer Cells*

    Get PDF
    Current therapies for prostate cancer include antiandrogens, inhibitory ligands of the androgen receptor, which repress androgen-stimulated growth. These include the selective androgen receptor modulators cyproterone acetate and hydroxyflutamide and the complete antagonist bicalutamide. Their activity is partly dictated by the presence of androgen receptor mutations, which are commonly detected in patients who relapse while receiving antiandrogens, i.e. in castrate-resistant prostate cancer. To characterize the early proteomic response to these antiandrogens we used the LNCaP prostate cancer cell line, which harbors the androgen receptor mutation most commonly detected in castrate-resistant tumors (T877A), analyzing alterations in the proteome, and comparing these to the effect of these therapeutics upon androgen receptor activity and cell proliferation. The majority are regulated post-transcriptionally, possibly via nongenomic androgen receptor signaling. Differences detected between the exposure groups demonstrate subtle changes in the biological response to each specific ligand, suggesting a spectrum of agonistic and antagonistic effects dependent on the ligand used. Analysis of the crystal structures of the AR in the presence of cyproterone acetate, hydroxyflutamide, and DHT identified important differences in the orientation of key residues located in the AF-2 and BF-3 protein interaction surfaces. This further implies that although there is commonality in the growth responses between androgens and those antiandrogens that stimulate growth in the presence of a mutation, there may also be influential differences in the growth pathways stimulated by the different ligands. This therefore has implications for prostate cancer treatment because tumors may respond differently dependent upon which mutation is present and which ligand is activating growth, also for the design of selective androgen receptor modulators, which aim to elicit differential proteomic responses dependent upon cellular context

    Characterization of atrazine-induced gonadal malformations in African clawed frogs (Xenopus laevis) and comparisons with effects of an androgen antagonist (cyproterone acetate) and exogenous estrogen (17beta-estradiol): Support for the demasculinization/feminization hypothesis.

    Get PDF
    Atrazine is a potent endocrine disruptor that both chemically castrates and feminizes male amphibians. It depletes androgens in adult frogs and reduces androgen-dependent growth of the larynx in developing male larvae. It also disrupts normal gonadal development and feminizes the gonads of developing males. Gonadal malformations induced by atrazine include hermaphrodites and males with multiple testes [single sex polygonadism (SSP)], and effects occur at concentrations as low as 0.1 ppb (microg/L). Here, we describe the frequencies at which these malformations occur and compare them with morphologies induced by the estrogen, 17beta-estradiol (E2) , and the antiandrogen cyproterone acetate, as a first step in testing the hypothesis that the effects of atrazine are a combination of demasculinization and feminization. The various forms of hermaphroditism did not occur in controls. Nonpigmented ovaries, which occurred at relatively high frequencies in atrazine-treated larvae, were found in four individuals out of more than 400 controls examined (1%). Further, we show that several types of gonadal malformations (SSP and three forms of hermaphroditism) are produced by E2 exposure during gonadal differentiation, whereas a final morphology (nonpigmented ovaries) appears to be the result of chemical castration (disruption of androgen synthesis and/or activity) by atrazine. These experimental findings suggest that atrazine-induced gonadal malformations result from the depletion of androgens and production of estrogens, perhaps subsequent to the induction of aromatase by atrazine, a mechanism established in fish, amphibians, reptiles, and mammals (rodents and humans)
    • 

    corecore