Search results for " Androgens"
showing 10 items of 10 documents
Evolution of yolk androgens in birds: development, coloniality and sexual dichromatism
2007
18 pages; International audience; Current theory recognizes the adaptive value of maternal effects in shaping offspring phenotypes in response to selective pressures and vindicates the value of these traits in fostering adaptation and speciation. Yolk androgens in birds are a relatively well-known maternal effect and have been linked to adaptations related to development, coloniality life, and sexual selection. We tested whether interspecific patterns of yolk androgen levels (androstenedione and testosterone) were related to interspecific variation in development, sexual selection, and coloniality. First, we found no relationship between androgen levels and duration of development as reflec…
Effects of Nandrolone Stimulation on Testosterone Biosynthesis in Leydig Cells
2016
Anabolic androgenic steroids (AAS) are among the drugs most used by athletes for improving physical performance, as well as for aesthetic purposes. A number of papers have showed the side effects of AAS in different organs and tissues. For example, AAS are known to suppress gonadotropin‐releasing hormone, luteinizing hormone, and follicle‐stimulating hormone. This study investigates the effects of nandrolone on testosterone biosynthesis in Leydig cells using various methods, including mass spectrometry, western blotting, confocal microscopy and quantitative real‐time PCR. The results obtained show that testosterone levels increase at a 3.9 μM concentration of nandrolone and return to the ba…
Training volume, androgen use and serum creatine kinase activity.
1989
Serum creatine kinase (CK) activities were investigated in elite male strength athletes (n = 20) during normal weight training and bodybuilding training (one training session per day), during high volume strength training (two sessions per day) and during strength training (one session per day) with the use of high dose synthetic androgens (five athletes in each subgroup). The findings demonstrated that the increase in serum CK was highest in the subgroup using androgens. These results suggest that strength training with the use of androgenic steroids leads to higher serum CK activities than normal strength training.
Clinical and endocrine characteristics of the main polycystic ovary syndrome phenotypes
2009
Abstract OBJECTIVE: To evaluate the clinical and endocrine differences between main polycystic ovary syndrome (PCOS) phenotypes. DESIGN: To evaluate clinical and hormone parameters in a large group of consecutive women with PCOS diagnosed according Rotterdam criteria and divided according their phenotype. SETTING: University department of medicine. PATIENT(S): Three hundred eighty-two consecutive women with PCOS and 85 ovulatory controls. INTERVENTION(S): Evaluation of clinical and hormone parameters. MAIN OUTCOME MEASURE(S): Blood levels of gonadotropins, testosterone, sex-hormone-binding globulin, dehydroepiandrosterone sulfate, 17α-hydroxyprogesterone, progesterone, glucose, and insulin,…
A 20-year follow-up of young women with polycystic ovary syndrome.
2012
OBJECTIVE: To determine whether hormonal, metabolic, and anthropomorphic parameters change over 20 years in women with polycystic ovary syndrome (PCOS). METHODS: One hundred ninety-three women with PCOS, aged 20–25 years, were diagnosed according to Rotterdam criteria, divided into four phenotypes (A–D), and followed at 5-year intervals for 20 years. Androgens, gonadotropins, insulin, glucose, body mass index, waist circumference, and ovarian volume were measured. RESULTS: At diagnosis, 57% had classic features (phenotype A), 9% had classic features without ovarian findings (phenotype B), 26% had the ovulatory phenotype (C), and 7% were nonhyperandrogenic (D). After 10 years, androgens decr…
Contrasting parental roles shape sex differences in poison frog space use but not navigational performance
2022
Sex differences in vertebrate spatial abilities are typically interpreted under the adaptive specialization hypothesis, which posits that male reproductive success is linked to larger home ranges and better navigational skills. The androgen spillover hypothesis counters that enhanced male spatial performance may be a byproduct of higher androgen levels. Animal groups that include species where females are expected to outperform males based on life-history traits are key for disentangling these hypotheses. We investigated the association between sex differences in reproductive strategies, spatial behavior, and androgen levels in three species of poison frogs. We tracked individuals in natura…
The waiting time for prostate cancer treatment in Italy: analysis from the PROS-IT CNR Study.
2022
Background Prostate cancer (PCa) is the second most common neoplasm in male patients. To date, there's no certain indication about the maximum waiting time (WT) acceptable for treatment beginning and the impact on oncological and functional outcomes has not been well established. Methods Data from the National Research Council PCa monitoring multicenter project in Italy (Pros-IT CNR) were prospectively collected and analyzed. WT was defined as the time from the bioptical diagnosis of PCa to the first treatment received. Patients were divided in two groups, using a time frame of 90 days. Quality of life was measured through the Italian version of the University of California Los Angeles-Pros…
Serum androsterone conjugates differentiate between acne and hirsutism in hyperandrogenic women
1991
Objective To determine if among hyperandrogenic women acne may be differentiated from hirsutism by markers of peripheral androgen metabolism. Design Prospective outpatient study of 36 hyperandrogenic women and controls divided into groups based on the presence or absence of significant hirsutism and the presence or absence of moderate to severe acne. Serum levels of adrenal and ovarian derived androgens were elevated but similar in all patient groups. Interventions Measurement of serum androgens including metabolites of 5 α -reductase activity: 3 α -androstanediol glucuronide and sulfate and androsterone (A) glucuronide and sulfate. Results 3 α -androstanediol glucuronide and sulfate were e…
Neridronate prevents bone loss in patients receiving androgen deprivation therapy for prostate cancer.
2004
Today, androgen deprivation therapy is a cornerstone of treatment for advanced prostate cancer, although it presents important complications such as osteoporosis. Neridronate, a relatively new bisphosphonate, is able to prevent bone loss in patients with prostate cancer during androgen ablation. Introduction: Androgen-deprivation therapy (ADT) is a cornerstone of treatment for advanced prostate cancer. This therapy has iatrogenic complications, such as osteoporosis. The aim of our study was to evaluate the efficacy of neridronate, a relatively new bisphosphonate, to prevent bone loss during androgen ablation. Materials and Methods: Forty-eight osteoporotic patients with prostate cancer, tre…
Sex steroid hormone receptors, their ligands, and nuclear and non-nuclear pathways
2015
The ability of a cell to respond to a particular hormone depends on the presence of specific receptors for those hormones. Once the hormone has bound to its receptor, and following structural and biochemical modifications to the receptor, it separates from cytoplasmic chaperone proteins, thereby exposing the nuclear localization sequences that result in the activation of the receptor and initiation of the biological actions of the hormone on the target cell. In addition, recent work has demonstrated new pathways of steroid signaling through orphan and cell surface receptors that contribute to more rapid, “non-nuclear” or non-transcriptional effects of steroid hormones, often involving G-pro…