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Endogenous Testosterone

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https://www.readbyqxmd.com/read/27870444/sex-differences-and-estrogen-regulation-of-bdnf-gene-expression-but-not-propeptide-content-in-the-developing-hippocampus
#1
Katherine E Kight, Margaret M McCarthy
Sex differences in adult brain function are frequently determined developmentally through the actions of steroid hormones during sensitive periods of prenatal and early postnatal life. In rodents, various cellular end points of the developing brain are affected by estradiol that is derived from the aromatization of circulating testosterone and/or synthesized within the brain. We have previously described a sex difference in neurogenesis in the hippocampus of neonatal rats that is modulated by estradiol. In this report, we examined a potential downstream regulator of the effects of estradiol on hippocampal cell proliferation by measuring gene expression of brain-derived neurotrophin (BDNF) in male and female neonatal rats in response to estradiol...
January 2, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/27865788/testosterone-and-immune-reproductive-tradeoffs-in-healthy-women
#2
Tierney K Lorenz, Julia R Heiman, Gregory E Demas
Although testosterone (T) has been characterized as universally immunosuppressive across species and sexes, recent ecoimmunology research suggests that T's immunomodulatory effects (enhancing/suppressing) depend on the organism's reproductive context. Very little is known about the immune effects of T in healthy females, and even less about how reproductive effort modulates the immune effects of T in humans. We investigated how the interaction between endogenous T and sexual activity predicted menstrual cycle-related changes in several measures of immunity: inflammation (indexed by interleukin-6, IL-6), adaptive immunity (indexed by immunoglobulin A, IgA), and functional immunity (indexed by bactericidal assay)...
November 17, 2016: Hormones and Behavior
https://www.readbyqxmd.com/read/27861588/endogenous-testosterone-and-exogenous-oxytocin-modulate-attentional-processing-of-infant-faces
#3
Sarah K C Holtfrerich, Katharina A Schwarz, Christian Sprenger, Luise Reimers, Esther K Diekhof
Evidence indicates that hormones modulate the intensity of maternal care. Oxytocin is known for its positive influence on maternal behavior and its important role for childbirth. In contrast, testosterone promotes egocentric choices and reduces empathy. Further, testosterone decreases during parenthood which could be an adaptation to increased parental investment. The present study investigated the interaction between testosterone and oxytocin in attentional control and their influence on attention to baby schema in women...
2016: PloS One
https://www.readbyqxmd.com/read/27852981/no-effect-of-testosterone-on-behavior-in-aged-wistar-rats
#4
Veronika Borbélyová, Emese Domonkos, Janka Bábíčková, Ľubomíra Tóthová, Martin Bosý, Július Hodosy, Peter Celec
In men, aging is accompanied by a gradual decline in androgen secretion. Studies suggest beneficial effects of endogenous and exogenous testosterone on affective behavior and cognitive functions. The aim of this study was to describe behavioral and cognitive sex differences and to analyze the effects of long-term androgen deficiency in aged male rats. Thirty-months old rats divided into three groups (males, females and males gonadectomized as young adults) underwent a battery of behavioral tests assessing locomotor activity, anxiety, memory, anhedonia, sociability and depression-like behavior...
November 12, 2016: Aging
https://www.readbyqxmd.com/read/27836607/molecularly-imprinted-polymers-on-graphene-oxide-surface-for-eis-sensing-of-testosterone
#5
Weilu Liu, Yukai Ma, Guoxiang Sun, Shupiao Wang, Jiayin Deng, Hong Wei
A novel electrochemical biosensor was developed for ultrasensitive determination of testosterone from femtomolar to micromolar levels via electrochemical impedance spectroscopy (EIS) measurements. The sensor features a nanosized molecularly imprinted polymer (MIP) film that was electrochemically grafted on a graphene-oxide sheets modified electrode. The detection mechanism of this senor is explained via the change of the interfacial impedance that derived from the recognition of the target molecule. Due to the nanosheet structure as well as the high surface area of graphene-oxide, the sensitivity of the MIP sensor is enhanced remarkably...
November 5, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27797446/cross-sectional-association-of-endogenous-steroid-hormone-sex-hormone-binding-globulin-and-precursor-steroid-levels-with-hemostatic-factor-levels-in-postmenopausal-women
#6
Laura B Harrington, Brett T Marck, Kerri L Wiggins, Barbara McKnight, Susan R Heckbert, Nancy F Woods, Andrea Z LaCroix, Marc Blondon, Bruce M Psaty, Frits R Rosendaal, Alvin M Matsumoto, Nicholas L Smith
BACKGROUND: Oral use of exogenous estrogen/progestin alters hemostatic factor levels. The influence of endogenous hormones on these levels is incompletely characterized. OBJECTIVES: Our study aimed to test whether, among postmenopausal women, high levels of estradiol (E2), estrone (E1), testosterone (T), dehydroepiandrosterone-sulfate (DHEAS), DHEA, and androstenedione, and low levels of sex hormone-binding globulin (SHBG), are positively associated with measures of thrombin generation (TG), normalized activated protein C sensitivity ratio (nAPCsr), and factor VII activity (FVIIc), and negatively associated with antithrombin activity (ATc) and total protein S antigen (PSAg)...
October 31, 2016: Journal of Thrombosis and Haemostasis: JTH
https://www.readbyqxmd.com/read/27793455/effects-of-long-acting-gnrh-antagonist-degarelix-acetate-on-plasma-insulin-like-peptide-3-testosterone-and-luteinizing-hormone-concentrations-and-scrotal-circumference-in-male-goats
#7
M A Hannan, N Kawate, Y Fukami, W W P N Weerakoon, E E Büllesbach, T Inaba, H Tamada
We recently reported that plasma insulin-like peptide 3 (INSL3) concentrations increased soon after endogenous and exogenous stimulations of LH in male goats and bulls. However, the effects of LH suppression on INSL3 secretion are unknown in domestic animals. Here, we examined the effects of a long-acting GnRH antagonist (degarelix acetate; 4 mg/kg) on the secretions of plasma INSL3 and testosterone in two phases, an immediate and a long-term phase in male goats (n = 6; aged, 13-16 months). During the immediate phase, blood was taken at 15-minute intervals for 8 hours on Days -5, 0, and 3...
January 15, 2017: Theriogenology
https://www.readbyqxmd.com/read/27739243/optimization-of-an-on-line-heart-cutting-multidimensional-gas-chromatography-clean-up-step-for-isotopic-ratio-mass-spectrometry-and-simultaneous-quadrupole-mass-spectrometry-measurements-of-endogenous-anabolic-steroid-in-urine
#8
Alessandro Casilli, Thomas Piper, Fábio Azamor de Oliveira, Monica Costa Padilha, Henrique Marcelo Pereira, Mario Thevis, Francisco Radler de Aquino Neto
Measuring carbon isotope ratios (CIR) of urinary analytes represents a cornerstone of doping control analysis and has been particularly optimized for the detection of the misuse of endogenous steroids. Isotope ratio mass spectrometry (IRMS) of appropriate quality however necessitates adequate purities of the investigated steroids, which requires extensive pre-analytical sample clean-up steps due to both, the natural presence of the target analytes and the high complexity of the matrix. In order to accelerate the sample preparation and increase the automation of the process, the use of multidimensional gas chromatography (MDGC) prior to IRMS experiments, was investigated...
October 14, 2016: Drug Testing and Analysis
https://www.readbyqxmd.com/read/27732769/longitudinal-evaluation-of-the-isotope-ratio-mass-spectrometric-data-towards-the-isotopic-module-of-the-athlete-biological-passport
#9
Daniel Jardines, Francesco Botrè, Cristiana Colamonici, Davide Curcio, Gemma Procida, Xavier de la Torre
The detection of the abuse of pseudo-endogenous steroids (testosterone and/or its precursors) is currently based on the application of the steroid module of the World Anti-Doping Agency (WADA) Athletes' Biological Passport (ABP), implemented through ADAMS. Diagnostic metabolites are monitored for every athlete and statistically evaluated with a predictive Bayesian approach. In the case of suspicious samples, the data of the ABP are confirmed and the isotope ratio mass spectrometry (IRMS) test is activated. We have previously demonstrated that IRMS enables confirmation of the non-endogenous origin of pseudo-endogenous steroids in otherwise non-suspicious samples, after a longitudinal evaluation of the ABP, even after the inclusion of additional long-term diagnostic hydroxylated metabolites, and that the delta values of the parameters obtained during the IRMS confirmation process presented much less variability compared to the parameters of the ABP...
October 12, 2016: Drug Testing and Analysis
https://www.readbyqxmd.com/read/27729576/association-between-endogenous-testosterone-and-cerebrovascular-disease-in-the-aric-study-atherosclerosis-risk-in-communities
#10
Reshmi Srinath, Rebecca F Gottesman, Sherita Hill Golden, Kathryn A Carson, Adrian Dobs
BACKGROUND AND PURPOSE: Epidemiological studies in men suggest a relationship between endogenous testosterone and ischemic vascular events. We hypothesized that low testosterone is independently associated with ischemic stroke and ischemic brain changes. METHODS: In 1558 male participants (mean [SD] age, 63.1 [5.6] years; body mass index, 28.2 [4.3] kg/m(2)) from visit 4 (1996-1998) of the ARIC study (Atherosclerosis Risk in Communities) without cardiovascular disease, stroke, and previous testosterone therapy, we measured plasma total testosterone by liquid chromatography mass spectrometry using morning samples and divided levels into tertiles (median [25th-75th percentile], 377...
November 2016: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/27723957/potential-detection-of-low-dose-transdermal-testosterone-administration-in-blood-urine-and-saliva
#11
M Schönfelder, H Hofmann, T Schulz, T Engl, D Kemper, B Mayr, C Rautenberg, R Oberhoffer, D Thieme
Administration of low amounts of endogenous hormones - so-called micro-dosages - are supposed to represent a major challenge in doping analysis. To model such a situation, we have studied transdermal administrations of 2.4 mg/24 h testosterone patches and examined various steroid concentrations in blood, urine, and saliva of 11 volunteers. Multiple samples were collected at t = 0, 3, 6, 9, 24, 48, and 72 h in four different phases, i.e., all combinations with/without physical exercise and with/without testosterone...
October 10, 2016: Drug Testing and Analysis
https://www.readbyqxmd.com/read/27716536/an-in-vivo-assay-performed-using-multiple-biomarkers-related-to-testosterone-synthesis-and-conversion-for-assessing-the-androgenic-potency-of-refuse-leachate
#12
Yufeng Gong, Hua Tian, Yifei Dong, Xiaona Zhang, Wei Wang, Shaoguo Ru
Refuse leachate is likely an important source of androgens. However, common in vitro bioassays underestimate the potential androgenic activity of leachate, owing to non-receptor-mediated mechanisms that modify the balance of sex hormones and promote the accumulation of endogenous androgens. This study aimed to develop an in vivo assay by using multiple biomarkers related to testosterone synthesis and conversion for assessing the potential androgenic activity of refuse leachate sampled from a municipal solid waste treatment plant in Qingdao, China...
October 4, 2016: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/27702564/testosterone-and-androgen-receptor-gene-polymorphism-are-associated-with-confidence-and-competitiveness-in-men
#13
Christoph Eisenegger, Robert Kumsta, Michael Naef, Jörg Gromoll, Markus Heinrichs
A contribution to a special issue on Hormones and Human Competition Studies in non-human animals and humans have demonstrated the important role of testosterone in competitive interactions. Here, we investigated whether endogenous testosterone levels predict the decision to compete, in a design excluding spite as a motive underlying competitiveness. In a laboratory experiment with real monetary incentives, 181 men solved arithmetic problems, first under a noncompetitive piece rate, followed by a competition incentive scheme...
October 1, 2016: Hormones and Behavior
https://www.readbyqxmd.com/read/27698208/regulation-of-steroidogenesis-in-fetal-bovine-ovaries-differential-effects-of-lh-and-fsh
#14
Jeremy J Allen, Susan L Herrick, Joanne E Fortune
In cattle, primordial follicles form before birth. Fetal ovarian capacity to produce progesterone and estradiol is high before follicle formation begins and decreases around the time follicles first appear (around 90 days of gestation). However, mechanisms that regulate steroid production during this time remain unclear. We hypothesized that LH stimulates progesterone and androgen production and that FSH stimulates aromatization of androgens to estradiol. To test this, we cultured pieces from fetal bovine ovaries for 10 days without or with exogenous hormones and then measured the accumulation of steroids in the culture medium by RIA...
October 3, 2016: Journal of Molecular Endocrinology
https://www.readbyqxmd.com/read/27682404/simultaneous-determination-of-seven-neuroactive-steroids-associated-with-depression-in-rat-plasma-and-brain-by-high-performance-liquid-chromatography-tandem-mass-spectrometry
#15
Youqiong Wang, Lipeng Tang, Wei Yin, Jiesi Chen, Tiandong Leng, Xiaoke Zheng, Wenbo Zhu, Haipeng Zhang, Pengxin Qiu, Xiaoxiao Yang, Guangmei Yan, Haiyan Hu
Sensitive and specific biomarkers are required for the diagnosis and treatment of depression because the existing diagnostic criteria are subjective and could produce false positives or negatives. Some endogenous neuroactive steroids that have shown either antidepressant effects or concentration changes in individuals with depression could provide potential biomarkers. In this study, a simple and specific method was developed to simultaneously determine seven endogenous neuroactive steroids in biological samples: cortisone, cortisol, dehydroepiandrosterone, estradiol, progesterone, pregnenolone, and testosterone...
2016: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/27676129/spatial-localization-and-quantitation-of-androgens-in-mouse-testis-by-mass-spectrometry-imaging
#16
Diego F Cobice, Dawn E W Livingstone, C Logan Mackay, Richard J A Goodwin, Lee B Smith, Brian R Walker, Ruth Andrew
Androgens are essential for male development and reproductive function. They are transported to their site of action as blood-borne endocrine hormones but can also be produced within tissues to act in intracrine and paracrine fashions. Because of this, circulating concentrations may not accurately reflect the androgenic influence within specific tissue microenvironments. Mass spectrometry imaging permits regional analysis of small molecular species directly from tissue surfaces. However, due to poor ionization and localized ion suppression, steroid hormones are difficult to detect...
October 14, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27673553/regulated-and-functional-expression-of-the-corepressor-mta3-in-rodent-testis
#17
Ke He, Hu Qu, Hui Wang, Shun Zhang, Xin-Hong Qian, Wei Li
Metastasis-associated protein 3 (MTA3) is a subunit of the Mi-2/nucleosome remodeling and deacetylase (NuRD) protein complex, with relevant roles in the regulation of cancerous epithelial to mesenchymal transition (ETM) in an estrogen-dependent manner, recently involved in the modulation of different physiological processes. Although these findings connect MTA3 expression with hormonal signaling in various systems, little is known about whether this relationship is conserved in testis where hormonal action is intensive...
September 27, 2016: Endocrinology
https://www.readbyqxmd.com/read/27663363/experimental-elevation-of-wildlife-testosterone-using-silastic-tube-implants
#18
Efrat Koresh, Devorah Matas, Lee Koren
Testosterone (T) is a key androgen that mediates vertebrate molecular, cellular, and behavioral processes. Its manipulation is therefore of interest to a vast number of researchers studying animal behavior and reproduction, among others. Here, the usage of silastic implants across wildlife species is reviewed, and a method to manipulate rock hyrax (Procavia capensis) testosterone levels using silastic implants is presented. Using a series of in-vitro and in-vivo experiments, the secretion patterns of silastic tubes and silastic glue were tested and were surprisingly found to be similar...
October 2016: Research in Veterinary Science
https://www.readbyqxmd.com/read/27662450/effects-of-testosterone-therapy-on-cognitive-function-in-aging-a-systematic-review
#19
Jeremy T Hua, Kerry L Hildreth, Victoria S Pelak
Endogenous testosterone in the aging man has been scrutinized extensively in regard to its effects on performance in many cognitive domains, especially verbal fluency, visuospatial and visuoperceptual abilities, memory, and executive function. Studies of testosterone supplementation have sought to identify potential cognitive improvements in men with and without baseline cognitive impairment, and have had a wide range of results. The variability in outcomes is likely related, in part, to the lack of consensus on methods for testosterone measurement and supplementation and, in part, to the disparate measures of cognitive function used in randomized controlled studies...
September 2016: Cognitive and Behavioral Neurology: Official Journal of the Society for Behavioral and Cognitive Neurology
https://www.readbyqxmd.com/read/27603705/pressure-pain-threshold-and-beta-endorphins-plasma-level-are-higher-in-lean-polycystic-ovary-syndrome-women
#20
Marta Kiałka, Tomasz Milewicz, Sandra Mrozińska, Iwona Rogatko, Krystyna Sztefko, Renata Majewska
BACKGROUND: Despite some evidence that indicates that the evolution of PCOS is related to the activity of the endogenous opioid system, and that concentration of plasma β-endorphin levels can increase pain threshold, there are no studies which evaluate pressure pain threshold in the PCOS women population. METHODS: In 48 lean women with PCOS and 38 lean women without this disorder plasma β-endorphins and PPT were measured. RESULTS: The Beta-endorphins level was higher in the PCOS group compared to the controls (15...
September 7, 2016: Minerva Endocrinologica
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