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Testosterone and implant

Ahmed Bulldan, Mazen Shihan, Sandra Goericke-Pesch, Georgios Scheiner-Bobis
A gonadotropin-releasing hormone agonist (GnRH-A) implant induces hormonal castration in dogs that is associated with reduced prostate and testes size. We address the molecular events associated with hormonal castration by examining GnRH-A effects on expression and phosphorylation of a number of key signaling proteins. Male beagles were treated for 5 months with a GnRH-A implant, and then surgically castrated at 0, 3, 6, 12, and 24 weeks after implant removal; untreated animals served as controls. GnRH-A treatment led to activation of c-Raf, Erk1/2, and p53 in the testes...
October 20, 2016: Molecular Reproduction and Development
Heather A Molenda-Figueira, Margaret R Bell, Kayla C De Lorme, Cheryl L Sisk
This study examined the effects of pubertal testosterone (T) and social housing manipulations on male sexual behavior in adult rats. Prepubertal rats were castrated at 21 days of age (P21) and implanted with either blank or T-releasing pellets. At the onset of puberty, P28, half the rats in each treatment group were either single- or pair-housed with a male of the same hormone condition through P56, at which time pellets were removed and all rats were single-housed. In adulthood (P84), all rats received T replacement and were tested for sexual behavior...
October 7, 2016: Developmental Psychobiology
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
Pheruza Tarapore, Max Hennessy, Dan Song, Jun Ying, Bin Ouyang, Vinothini Govindarajah, Yuet-Kin Leung, Shuk-Mei Ho
Exposure to xenoestrogens is a probable cause of male infertility in humans. Consumption of high-fat diets and exposure to bisphenol A (BPA) is pervasive in America. Here, we test the hypothesis that gestational exposure to high dietary fats and/or BPA disrupt spermatogenesis in adulthood. Sprague-Dawley rats were fed diets containing 10 kcal% butter fat (AIN), 39 kcal% butter fat (HFB), or 39 kcal% olive oil (HFO), with or without BPA (25μg/kg body weight/day) during pregnancy. One group of male offspring received testosterone (T)- and estradiol-17β (E2)-filled implants or sham-implants from postnatal day (PND)70-210...
September 19, 2016: Reproductive Toxicology
Priya Bhide, Åse Vårtun, Berit Aune, Kari Flo, Purusotam Basnet, Ganesh Acharya
PURPOSE: Severe pre-eclampsia affects maternal health with long-term consequences. It is postulated that during the process of implantation and cell differentiation, embryos resulting from the fertilization of ageing oocytes produce malfunctioning trophoectoderm leading to placental dysfunction. Therefore, severe pre-eclampsia may be associated with a decreased ovarian reserve. The objective of this study was to compare serum markers of ovarian reserve and function between women who had severe pre-eclampsia and those who had normal pregnancies...
September 7, 2016: Archives of Gynecology and Obstetrics
Haolin Chen, Shiying Jin, Shengsong Huang, Janet Folmer, June Liu, Renshan Ge, Barry R Zirkin
In vivo and in vitro studies were conducted to determine whether testosterone-producing Leydig cells are able to develop from cells associated with rat seminiferous tubules, interstitium, or both. Adult rat seminiferous tubules and interstitium were isolated, encapsulated separately in alginate, and implanted subcutaneously into castrated rats. With implanted tubules, serum testosterone increased through two months. Tubules removed from the implanted rats and incubated with LH produced testosterone, and cells on the tubule surfaces expressed steroidogenic enzymes...
November 15, 2016: Molecular and Cellular Endocrinology
Matthias D Hofer, Allen F Morey, Kunj Sheth, Timothy J Tausch, Jordan Siegel, Billy H Cordon, Matthew I Bury, Earl Y Cheng, Arun K Sharma, Chris M Gonzalez, William E Kaplan, Nicholas L Kavoussi, Alexandra Klein, Claus G Roehrborn
OBJECTIVE: To examine the association between decreased serum testosterone levels and AUS cuff erosion. METHODS: We evaluated serum testosterone levels in 53 consecutive patients. Low testosterone was defined as <280 ng/dl and found in 30/53 patients (56.6%). Chi-square and Student's t tests, Kaplan-Meier analysis, binary logistic regression and Cox regression analysis were used to determine statistical significance. RESULTS: Nearly all men with AUS cuff erosions had low serum testosterone (18/20, 90...
July 20, 2016: Urology
Joseph F Lynch, Tyler Vanderhoof, Patrick Winiecki, Maeson S Latsko, David C Riccio, Aaron M Jasnow
Generalization is a common symptom of many anxiety disorders, and females are 60% more likely to suffer from an anxiety disorder than males. We have previously demonstrated that female rats display significantly accelerated rates of contextual fear generalization compared to male rats; a process driven, in part, by activation of ERβ. The current study was designed to determine the impact of estrogens on contextual fear generalization in male rats. For experiment 1, adult male rats were gonadectomized (GDX) and implanted with a capsule containing testosterone proprionate, estradiol, dihydrotestosterone proprionate (DHT), or an empty capsule...
August 2016: Hormones and Behavior
D Herrera-Covarrubias, M B Tecamachaltzi-Silvaran, M Barradas-Moctezuma, J B Rosales-Raya, J Manzo, L I García, G E Aranda-Abreu, N Ismail, G A Coria-Avila, M E Hernández
UNLABELLED: The prostate is an exocrine reproductive gland that participates in ejaculation and it is prone to diseases, including cancer. AIM: In the pre-sent study, we assessed the long-term effects of copulation on the development of precancerous lesions in rats, and compared them with testosterone-induced prostatic lesions. MATERIALS AND METHODS: One group of Wistar males was given 10 copulatory sessions to one ejaculation with ovariectomized, hormone-primed females...
June 2016: Experimental Oncology
Marciana Sanabria, Maira Smaniotto Cucielo, Marina Trevizan Guerra, Cibele Dos Santos Borges, Thais Petrochelli Banzato, Juliana Elaine Perobelli, Gabriel Adan Araújo Leite, Janete Aparecida Anselmo-Franci, Wilma De Grava Kempinas
Exposure to Tetrachlorodibenzo-p-Dioxin (TCDD) in male rats promotes, decreased sperm concentration, alterations in motility and in sperm transit time. We evaluated the effect transgenerational of in utero exposure to low doses TCDD in the sperm quality. Pregnant rats (F0) were exposed to 0.1; 0.5 and 1.0μg of TCDD, on gestational day 15, coincides with the end of most organogenesis in the fetus. Adult male offspring (F1, F2 and F3 generation) were investigated for fertility after artificial insemination in utero...
June 25, 2016: Reproductive Toxicology
Thomas Geninatti, R Lyle Hood, Giacomo Bruno, Priya Jain, Eugenia Nicolov, Arturas Ziemys, Alessandro Grattoni
Implantable devices may provide a superior means for hormone delivery through maintaining serum levels within target therapeutic windows. Zero-order administration has been shown to reach an equilibrium with metabolic clearance, resulting in a constant serum concentration and bioavailability of released hormones. By exploiting surface-to-molecule interaction within nanochannel membranes, it is possible to achieve a long-term, constant diffusive release of agents from implantable reservoirs. In this study, we sought to demonstrate the controlled release of model hormones from a novel nanochannel system...
August 2015: Materials
Muraly Puttabyatappa, Rodolfo C Cardoso, Carol Herkimer, Almudena Veiga-Lopez, Vasantha Padmanabhan
Gestational testosterone (TS) excess, acting via both the androgenic and estrogenic pathways, advances puberty and disrupts the neuroendocrine estradiol (E2) feedback and periovulatory hormonal dynamics in female sheep. These prenatally programmed defects may be subject to postnatal modifications by continued organizational and/or activational effects of steroids. This study investigated (1) the organizational contribution of prenatal estrogen excess and (2) the impact of postnatal exposure to E2 in modulating the effects of prenatal androgen excess (TS and dihydrotestosterone (DHT)) on puberty, neuroendocrine feedback mechanisms, and periovulatory hormonal dynamics in sheep...
August 2016: Reproduction: the Official Journal of the Society for the Study of Fertility
Michelle L Beck, Scott Davies, Ignacio T Moore, Laura A Schoenle, Kaan Kerman, Ben J Vernasco, Kendra B Sewall
Glucocorticoids can play a critical role in modulating life-history trade-offs. However, studying the effects of glucocorticoids on life-history often requires experimentally elevating plasma glucocorticoid concentrations for several weeks within normal physiological limits and without repeated handling of the animal. Recently, implants made of beeswax and testosterone (T) were shown to have release dynamics superior to some currently available T implants, and these beeswax implants dissolved, eliminating the need to recapture the animal...
July 1, 2016: General and Comparative Endocrinology
Masaya Fujiwara, Asano Nitta, Atsuhiko Chiba
Our previous study in male rats demonstrated that bilateral administration of flutamide, an androgen receptor (AR) antagonist, into the posterodorsal medial amygdala (MePD) increased the time sniffing male odors to as high as that sniffing estrous odors, eliminating the preference for estrous odors over male odors. This made us speculate that under blockade of AR in the MePD, testosterone-derived estrogen acting on the same brain region arouses interest in male odors which is otherwise suppressed by concomitant action of androgen...
June 2016: Hormones and Behavior
Hui-Xing Chen, Shi Yang, Ye Ning, Hai-Hao Shao, Meng Ma, Ru-Hui Tian, Yu-Fei Liu, Wei-Qiang Gao, Zheng Li, Wei-Liang Xia
Testicular prostheses have been used to deal with anorchia for nearly 80 years. Here, we evaluated a novel testicular prosthesis that can controllably release hormones to maintain physiological levels of testosterone in vivo for a long time. Silastic testicular prostheses with controlled release of testosterone (STPT) with different dosages of testosterone undecanoate (TU) were prepared and implanted into castrated Sprague-Dawley rats. TU oil was applied by oral administration to a separate group of castrated rats...
May 13, 2016: Asian Journal of Andrology
Marjorie J MacGregor, Cheryl S Asa, Donal C Skinner
Effective and humane management strategies for coyotes (Canis latrans) remain elusive. We hypothesised that exposure to a high dose of a gonadotrophin-releasing hormone (GnRH) agonist would cause prolonged suppression of the reproductive axis. Two groups of male coyotes were administered 47 mg deslorelin in the form of either five 9.4-mg controlled-release Suprelorin (Peptech Animal Health, Macquarie Park NSW, Australia) implants (n = 3) or 10 4.7-mg implants (n = 5). In the first group, deslorelin suppressed plasma LH, testosterone and testes volume in two of three coyotes for three breeding seasons...
May 10, 2016: Reproduction, Fertility, and Development
Ratna Ghosal, Peter W Sorensen
Male-typical reproductive behaviors vary greatly between different species of fishes with androgens playing a variety of roles that appear especially important in the gonochorist cypriniform fishes. The goldfish is an important model for the cypriniformes and while it is clear that male goldfish are fully feminized by prostaglandin F2α(PGF2α), it is not clear whether females will exhibit normal levels of male-typical reproductive behaviors as well as olfactory function when treated with androgens. To answer this question, we exposed sexually-regressed adult female goldfish to several types of androgen and monitored their tendencies to court (inspect females) and mate (spawn, or attempt to release gametes) while monitoring their olfactory sensitivity until changes in these attributes were maximized...
June 1, 2016: General and Comparative Endocrinology
Shai White-Gilbertson, Megan Davis, Christina Voelkel-Johnson, Laura M Kasman
OBJECTIVE: The MB49 syngeneic, murine model of bladder cancer has been widely used for more than 35 years. In humans, bladder cancer is one third as prevalent in women as in men, with a trend toward lower prevalence in parous compared to nulliparous women. Our objective was to determine if the MB49 bladder cancer model reproduces the sex differences observed in humans, and to determine its sensitivity to testosterone and the pregnancy hormone, human chorionic gonadotropin (hCG). METHODS: Male and female C57BL/6 mice were implanted with MB49 murine bladder cancer cells, and observed for tumor growth...
2016: Bladder
Juan Hong, Fang Chen, Xiaoli Wang, Yinyang Bai, Rong Zhou, Yingchun Li, Ling Chen
Previous studies have shown that bisphenol A (BPA) is a potential endocrine disruptor and testicular toxicant. The present study focused on exploring the impact of exposure to low dose of BPA on male reproductive development during the early embryo stage and the underlying mechanisms. BPA (20 μg/kg/day) was orally administered to female mice on days 1-5 of gestation. The male offspring were euthanized at PND10, 20, 24, 35 or PND50. We found that the mice exposed to BPA before implantation (BPA-mice) displayed retardation of testicular development with reduction of testosterone level...
May 15, 2016: Molecular and Cellular Endocrinology
Anne-Marie Saillenfait, Dieynaba Ndiaye, Jean-Philippe Sabaté, Flavien Denis, Guillaume Antoine, Alain Robert, Virginie Rouiller-Fabre, Delphine Moison
Pregnant Sprague-Dawley rats were administered deltamethrin, at doses 0.1, 1, 5 or 10 mg kg(-1)  day(-1) , or di-n-hexyl phthalate (DnHP) (250 mg kg(-1)  day(-1) ), by gavage, from gestational day 13 to 19. Maternal toxicity was observed at 10 mg kg(-1)  day(-1) , as evidenced by transient clinical signs of neurotoxicity and reductions in body weight, body weight gain and corrected weight gain. Deltamethrin had no statistically significant effect on the incidence of post-implantation loss, fetal weight or anogenital distance in the male fetuses...
November 2016: Journal of Applied Toxicology: JAT
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