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Testosterone synthesis

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https://www.readbyqxmd.com/read/27917368/sex-steroid-hormone-single-nucleotide-polymorphisms-pesticide-use-and-the-risk-of-prostate-cancer-a-nested-case-control-study-within-the-agricultural-health-study
#1
Carol H Christensen, Kathryn Hughes Barry, Gabriella Andreotti, Michael C R Alavanja, Michael B Cook, Scott P Kelly, Laurie A Burdett, Meredith Yeager, Laura E Beane Freeman, Sonja I Berndt, Stella Koutros
Experimental and epidemiologic investigations suggest that certain pesticides may alter sex steroid hormone synthesis, metabolism or regulation, and the risk of hormone-related cancers. Here, we evaluated whether single-nucleotide polymorphisms (SNPs) involved in hormone homeostasis alter the effect of pesticide exposure on prostate cancer risk. We evaluated pesticide-SNP interactions between 39 pesticides and SNPs with respect to prostate cancer among 776 cases and 1,444 controls nested in the Agricultural Health Study cohort...
2016: Frontiers in Oncology
https://www.readbyqxmd.com/read/27907900/insulin-resistance-in-polycystic-ovary-syndrome-a-systematic-review-and-meta-analysis-of-euglycaemic-hyperinsulinaemic-clamp-studies
#2
Samantha Cassar, Marie L Misso, William G Hopkins, Christopher S Shaw, Helena J Teede, Nigel K Stepto
STUDY QUESTION: What is the degree of intrinsic insulin resistance (IR) in women with polycystic ovary syndrome (PCOS) and the relative contribution of BMI to overall IR based on meta-analysis of gold standard insulin clamp studies? SUMMARY ANSWER: We report an inherent reduction (-27%) of insulin sensitivity (IS) in PCOS patients, which was independent of BMI. WHAT IS ALREADY KNOWN: PCOS is prevalent, complex and underpinned by IR but controversies surround the degree of intrinsic IR in PCOS, the effect of BMI and the impact of the different diagnostic criteria (NIH versus Rotterdam) in PCOS...
November 2016: Human Reproduction
https://www.readbyqxmd.com/read/27892862/melamine-negatively-affects-testosterone-synthesis-in-mice
#3
Jiarui Sun, Yinan Cao, Xinchen Zhang, Qiling Zhao, Endong Bao, Yingjun Lv
Several studies have found that melamine causes damage to the testes, epididymis and sperm. However, few studies have investigated the effect of melamine on the synthesis of testosterone, which plays an import role in testicular development and spermatogenesis. In present study, mice were orally administrated with 2, 10 or 50mg/kg of melamine for 28days. In these groups, various abnormalities were observed including disruption of the seminiferous tubule structure, an increased necrotic germ cells and sperm abnormalities, and a reduced sperm count...
October 13, 2016: Research in Veterinary Science
https://www.readbyqxmd.com/read/27890531/short-term-effects-of-diabetes-on-neurosteroidogenesis-in-the-rat-hippocampus
#4
Simone Romano, Nico Mitro, Silvia Diviccaro, Roberto Spezzano, Matteo Audano, Luis Miguel Garcia-Segura, Donatella Caruso, Roberto Cosimo Melcangi
Diabetes may induce neurophysiological and structural changes in the central nervous system (i.e., diabetic encephalopathy). We here explored whether the levels of neuroactive steroids (i.e., neuroprotective agents) in the hippocampus may be altered by short-term diabetes (i.e., one month). To this aim, by liquid chromatography-tandem mass spectrometry we observed that in the experimental model of the rat raised diabetic by streptozotocin injection, one month of pathology induced changes in the levels of several neuroactive steroids, such as pregnenolone, progesterone and its metabolites (i...
November 23, 2016: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/27888061/secretory-function-of-ovarian-cells-and-myometrial-contractions-in-cow-are-affected-by-chlorinated-insecticides-chlordane-heptachlor-mirex-in-vitro
#5
Michael Hubert Wrobel, Jaroslaw Mlynarczuk
The aim of the study was to investigate the effect of chlordane, heptachlor and mirex, on hormonal regulation of the force of myometrial contractions. Myometrial, endometrial, granulosa and luteal cells as well as strips of myometrium from non-pregnant cows were incubated with three insecticides at environmentally relevant doses (0.1, 1 or 10ng/ml). None of the insecticides affected the viability of studied cells. Chlordane stimulated, while heptachlor and mirex inhibited, secretion of testosterone and estradiol from granulosa cells as well as secretion of progesterone from luteal cells, respectively...
November 22, 2016: Toxicology and Applied Pharmacology
https://www.readbyqxmd.com/read/27888021/heightened-aggressive-behavior-in-mice-deficient-in-aldo-keto-reductase-1a-akr1a
#6
Takujiro Homma, Ryusuke Akihara, Satoshi Okano, Mototada Shichiri, Yasukazu Yoshida, Ken-Ichi Yamada, Satoshi Miyata, Osamu Nakajima, Junichi Fujii
Aldehyde reductase (Akr1a) is involved in the synthesis of ascorbic acid (AsA) which may play a role in social behavior. In the current study, we performed analyses on Akr1a-deficient (Akr1a(-/-)) mice that synthesize about 10% as much AsA as wild-type mice from the viewpoint of intermale aggression. The use of the resident-intruder test revealed that the Akr1a(-/-) mice exhibited more aggressive phenotypes than wild-type control mice. Unexpectedly, however, the oral administration of additional AsA failed to reduce the aggressive behavior of Akr1a(-/-) mice, suggesting that the heightened aggression was independent of AsA biosynthesis...
November 22, 2016: Behavioural Brain Research
https://www.readbyqxmd.com/read/27872709/the-effect-of-sugar-cane-molasses-on-the-immune-and-male-reproductive-systems-using-in-vitro-and-in-vivo-methods
#7
Farzana Rahiman, Edmund John Pool
OBJECTIVES: Sugar cane molasses is a commonly used ingredient in several food products. Contrasting reports suggest that molasses may have potential adverse or beneficial effects on human health. However, little evidence exists that examines the effects of molasses on the different physiological systems. This study investigated the effects of sugar cane molasses on various physiological systems using in vivo and in vitro methods. MATERIALS AND METHODS: Molasses was administered orally to BALB/c, male mice and animals were randomly assigned into either a treatment or control group...
October 2016: Iranian Journal of Basic Medical Sciences
https://www.readbyqxmd.com/read/27866972/letrozole-regulates-actin-cytoskeleton-polymerization-dynamics-in-a-src-1-dependent-manner-in-the-hippocampus-of-mice
#8
Yangang Zhao, Yanlan Yu, Yuanyuan Zhang, Li He, Linli Qiu, Jikai Zhao, Mengying Liu, Jiqiang Zhang
In the hippocampus, local estrogens (E2) derived from testosterone that is catalyzed by aromatase play important roles in the regulation of hippocampal neural plasticity, but the underlying mechanisms remain unclear. The actin cytoskeleton contributes greatly to hippocampal synaptic plasticity; however, whether it is regulated by local E2 and the related mechanisms remain to be elucidated. In this study, we first examined the postnatal developmental profiles of hippocampal aromatase and specific proteins responsible for actin cytoskeleton dynamics...
November 17, 2016: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/27860310/engineering-mycobacterium-smegmatis-for-testosterone-production
#9
Lorena Fernández-Cabezón, Beatriz Galán, José L García
A new biotechnological process for the production of testosterone (TS) has been developed to turn the model strain Mycobacterium smegmatis suitable for TS production to compete with the current chemical synthesis procedures. We have cloned and overexpressed two genes encoding microbial 17β-hydroxysteroid: NADP 17-oxidoreductase, from the bacterium Comamonas testosteroni and from the fungus Cochliobolus lunatus. The host strains were M. smegmatis wild type and a genetic engineered androst-4-ene-3,17-dione (AD) producing mutant...
November 17, 2016: Microbial Biotechnology
https://www.readbyqxmd.com/read/27853336/seventeen-alpha-hydroxylase-deficiency-associated-with-absent-gonads-and-myelolipoma-a-case-report-and-review-of-literature
#10
Mahmood Soveid, Ghanbar Ali Rais-Jalali
Congenital adrenal hyperplasia comprises a group of disorders resulting from defects in enzymes required for the synthesis of cortisol. The clinical presentation depends on the specific enzyme defect. We report a rare case of congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency. A 26-year-old female patient referred with hypertension and hypokalemia. She also had primary amenorrhea and lack of sexual development. The karyotype was 46, XY. Hormonal evaluation showed low serum levels of all steroid hormones, requiring alpha-hydroxylation, which included cortisol, 17 alpha-hydroxy progesterone, dehydroepiandrosterone sulfate, estradiol, and testosterone...
November 2016: Iranian Journal of Medical Sciences
https://www.readbyqxmd.com/read/27845856/modified-release-and-conventional-glucocorticoids-and-diurnal-androgen-excretion-in-congenital-adrenal-hyperplasia
#11
Christopher M Jones, Ashwini Mallappa, Nicole Reisch, Nikolaos Nikolaou, Nils Krone, Beverly A Hughes, Donna M O'Neil, Martin J Whitaker, Jeremy W Tomlinson, Karl-Heinz Storbeck, Deborah P Merke, Richard J Ross, Wiebke Arlt
CONTEXT: The classic androgen synthesis pathway proceeds via DHEA, androstenedione and testosterone to 5α-dihydrotestosterone (DHT). However, DHT synthesis can also be achieved by an alternative pathway originating from 17α-hydroxyprogesterone (17OHP), which accumulates in congenital adrenal hyperplasia (CAH). Similarly, recent work has highlighted androstenedione-derived 11-oxygenated 19-carbon steroids as active androgens and, in CAH, androstenedione is generated directly from 17OHP...
November 15, 2016: Journal of Clinical Endocrinology and Metabolism
https://www.readbyqxmd.com/read/27832095/increased-muscular-5%C3%AE-dihydrotestosterone-in-response-to-resistance-training-relates-to-skeletal-muscle-mass-and-glucose-metabolism-in-type-2-diabetic-rats
#12
Naoki Horii, Koji Sato, Noboru Mesaki, Motoyuki Iemitsu
Regular resistance exercise induces skeletal muscle hypertrophy and improvement of glycemic control in type 2 diabetes patients. Administration of dehydroepiandrosterone (DHEA), a sex steroid hormone precursor, increases 5α-dihydrotestosterone (DHT) synthesis and is associated with improvements in fasting blood glucose level and skeletal muscle hypertrophy. Therefore, the aim of this study was to investigate whether increase in muscle DHT levels, induced by chronic resistance exercise, can contribute to skeletal muscle hypertrophy and concomitant improvement of muscular glucose metabolism in type 2 diabetic rats...
2016: PloS One
https://www.readbyqxmd.com/read/27805753/dehydroepiandrosterone-dhea-heightens-aggression-and-increases-androgen-receptor-and-aromatase-mrna-expression-in-the-brain-of-a-male-songbird
#13
Douglas W Wacker, Sahar Khalaj, Lindsey J Jones, Tara L Champion, Jason E Davis, Simone L Meddle, John C Wingfield
Dehydroepiandrosterone, DHEA, is a testosterone/estrogen precursor and known modulator of vertebrate aggression. Male song sparrows (Melospiza melodia morphna) show high aggression during breeding and non-breeding life history stages when circulating DHEA levels are high, and low aggression during molt when DHEA levels are low. We previously showed that androgen receptor and aromatase mRNA expression are higher during breeding and/or non-breeding in brain regions associated with reproductive and aggressive behavior, but DHEA's potential role in mediating these seasonal changes remained unclear...
November 2, 2016: Journal of Neuroendocrinology
https://www.readbyqxmd.com/read/27799946/anti-m%C3%A3-llerian-hormone-as-a-marker-of-steroid-and-gonadotropin-action-in-the-testis-of-children-and-adolescents-with-disorders-of-the-gonadal-axis
#14
REVIEW
Nadia Y Edelsztein, Romina P Grinspon, Helena F Schteingart, Rodolfo A Rey
In pediatric patients, basal testosterone and gonadotropin levels may be uninformative in the assessment of testicular function. Measurement of serum anti-Müllerian hormone (AMH) has become increasingly widespread since it provides information about the activity of the male gonad without the need for dynamic tests, and also reflects the action of FSH and androgens within the testis. AMH is secreted in high amounts by Sertoli cells from fetal life until the onset of puberty. Basal AMH expression is not dependent on gonadotropins or sex steroids; however, FSH further increases and testosterone inhibits AMH production...
2016: International Journal of Pediatric Endocrinology
https://www.readbyqxmd.com/read/27797332/-experimental-study-of-the-influence-of-recombinant-human-lactoferrin-on-the-levels-of-androgens-and-basic-parameters-of-lipid-and-protein-metabolism
#15
Yu A Rudnichenko, V S Lukashevich, I V Zalutsky
System administration of human recombinant lactoferrin per os to rats for 2,5 months increased serum and testicular levels of total testosterone. The data correlated with the increase in free testosterone levels. These changes were accompanied by an increase of concentrations of steroidogenesis substrates (cholesterol, progesterone, and 17-OH progesterone) and a decrease of the estradiol content in blood serum. This resulted in the 3.6-3.8-fold increase of the testosterone/estradiol index. Basic parameters of lipid and protein were also studied...
July 2016: Biomedit︠s︡inskai︠a︡ Khimii︠a︡
https://www.readbyqxmd.com/read/27791460/effect-of-testosterone-on-the-proliferation-and-collagen-synthesis-of-cardiac-fibroblasts-induced-by-angiotensin-ii-in-neonatal-rat
#16
Xiaocun Yang, Ying Wang, Shuxun Yan, Lina Sun, Guojie Yang, Yuan Li, Chaonan Yu
The objective is to explore the effect of testosterone on the proliferation and collagen synthesis of neonatal rat cardiac fibroblasts (CF) induced by Angiotensin II (Ang II) and the underlying mechanisms. Derived from neonatal rats, the CFs were divided into 4 groups: the control group, Ang II group, testosterone group, and testosterone + Ang II group in vitro. Cell cycle distribution, collagen counts, and phosphorylated extracellular signal-regulated kinase (ERK1/2) (p - ERK1/2) expression were assessed by flow cytometry, VG staining, and immunocytochemistry, respectively...
October 28, 2016: Bioengineered
https://www.readbyqxmd.com/read/27788452/effects-of-alkylphenols-on-the-biotransformation-of-diuron-and-enzymes-involved-in-the-synthesis-and-clearance-of-sex-steroids-in-juvenile-male-tilapia-oreochromus-mossambica
#17
Andréia A Felício, Jordan Crago, Lindley A Maryoung, Eduardo A Almeida, Daniel Schlenk
Previous studies using in vivo bioassay guided fractionation indicated that the herbicide diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and alkylphenol (AP)-containing surfactants were detected in fractions of extracts that induced the estrogenic biomarker, vitellogenin in fish exposed to surface water extracts from the United States. However, when the compounds were evaluated individually using in vivo estrogenic assays or in vitro estrogen receptor assays, estrogenic activity was not observed. Since APs have been shown to alter activity and content of cytochrome P450s (CYP) which convert diuron to potential estrogenic metabolites, the hepatic biotransformation of diuron was measured with and without a 7day pretreatment of p-Octylphenol (OP) and p-Nonylphenol (NP) at low (OP 13ng/L+NP 91ng/L), and high concentrations (OP 65ng/L+NP 455ng/L) in juvenile male Nile tilapia (Oreochromus niloticus)...
October 22, 2016: Aquatic Toxicology
https://www.readbyqxmd.com/read/27785716/effects-of-increasing-temperature-due-to-aquatic-climate-change-on-the-self-fertility-and-the-sexual-development-of-the-hermaphrodite-fish-kryptolebias-marmoratus
#18
Chang-Beom Park, Young Jun Kim, Kiyoshi Soyano
In order to assess the effects of increasing temperature on the reproductive performance of fish, different thermal conditions (i.e., 25.0, 26.5, 27.5, 28.5, 30.0 °C) were used in this study and the self-fertilizing hermaphrodite fish, Kryptolebias marmoratus, was exposed to these different thermal conditions. During an exposure period of 30 to 150 days, the gonadosomatic index (GSI), gonadal development, the levels of plasma 17β-estradial (E2) and testosterone (T), hepatic vitellogenin (VTG) mRNA abundance, and the number of self-fertilized eggs were analyzed...
October 26, 2016: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/27773742/effects-of-isoliquiritigenin-on-ovarian-antral-follicle-growth-and-steroidogenesis
#19
Sharada Mahalingam, Liying Gao, Jacqueline Eisner, William Helferich, Jodi A Flaws
Isoliquiritigenin is a botanical estrogen used as a dietary supplement. Previous studies show that other botanical estrogens affect ovarian estradiol synthesis, but isoliquiritigenin's effects on the ovary are unknown. Thus, this study tested the hypothesis that isoliquiritigenin inhibits ovarian antral follicle growth and steroidogenesis. Antral follicles from CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or isoliquiritigenin (0.6μM, 6 μM, 36 μM, and 100 μM) for 48-96h. During culture, follicle diameters were measured daily to assess follicle growth...
December 2016: Reproductive Toxicology
https://www.readbyqxmd.com/read/27773737/microcystin-lr-causes-sexual-hormone-disturbance-in-male-rat-by-targeting-gonadotropin-releasing-hormone-neurons
#20
Xueting Wang, Jie Ding, Zou Xiang, Peipei Jiang, Jing Du, Xiaodong Han
Microcystin-LR (MC-LR), which generates strong reproductive toxicity, reduces serum testosterone level without directly damaging Leydig cells. The purpose of this study was to identify the target cells of MC-LR in the rat hypothalamic-pituitary axis and to investigate the underlying mechanisms. We found that the gonadotropin-releasing hormone (GnRH) neurons were the direct target of MC-LR. In vivo results showed that upon exposure to rats, cells around the third ventricle of hypothalamus underwent apoptosis...
October 20, 2016: Toxicon: Official Journal of the International Society on Toxinology
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