Testis Mass Research Articles

Sperm competition, sperm numbers and sperm quality in muroid rodents.

Sperm competition favors increases in relative testes mass and production efficiency, and changes in sperm phenotype that result in faster swimming speeds. However, little is known about its effects on traits that contribute to determine the quality of a whole ejaculate (i.e., proportion of motile, viable, morphologically normal and acrosome intact sperm) and that are key determinants of fertilization success. Two competing hypotheses lead to alternative predictions: (a) sperm quantity and quality traits co-evolve under sperm competition because they play complementary roles in determining ejaculate's competitive ability, or (b) energetic constraints force trade-offs between traits depending on their relevance in providing a competitive advantage. We examined relationships between sperm competition levels, sperm quantity, and traits that determine ejaculate quality, in a comparative study of 18 rodent species using phylogenetically controlled analyses. Total sperm numbers were positively correlated to proportions of normal sperm, acrosome integrity and motile sperm; the latter three were also significantly related among themselves, suggesting no trade-offs between traits. In addition, testes mass corrected for body mass (i.e., relative testes mass), showed a strong association with sperm numbers, and positive significant associations with all sperm traits that determine ejaculate quality with the exception of live sperm. An “overall sperm quality” parameter obtained by principal component analysis (which explained 85% of the variance) was more strongly associated with relative testes mass than any individual quality trait. Overall sperm quality was as strongly associated with relative testes mass as sperm numbers. Thus, sperm quality traits improve under sperm competition in an integrated manner suggesting that a combination of all traits is what makes ejaculates more competitive. In evolutionary terms this implies that a complex network of genetic and developmental pathways underlying processes of sperm formation, maturation, transport in the female reproductive tract, and preparation for fertilization must all evolve in concert.

Phenotypic plasticity in sex allocation for a simultaneously hermaphroditic coral reef fish

Phenotypic plasticity can facilitate reproductive strategies that maximize mating success in variable environments and lead to differences in sex allocation among populations. For simultaneous hermaphrodites with sperm competition, including Serranus tortugarum a small coral reef fish, proportional male allocation (testis in total gonad) is often greater where local density or mating group size is higher. We tested whether S. tortugarum reduced male allocation when transplanted from a higher density site to a lower density site. After 4 months, transplants mirrored the sex-allocation patterns of the resident population on their new reef. Transplants had significantly lower male allocation than representatives from their source population, largely as a result of reduced testis mass relative to body size.

Developmental and reproductive characteristics of western mosquitofish ( Gambusia affinis) exposed to paper mill effluent in the Dengcun River, Sihui, South China

The study reported in this paper tested the hypothesis that the developmental and reproductive health of mosquitofish ( Gambusia affinis) exposed to pulp and paper effluent in the Dengcun River would differ from that of mosquitofish living in a reference site. We also studied whether morphological characteristics such as the anal fin and hemal spines of mosquitofish could serve as indicators for evaluating the androgenic effect and mosquitofish population security in the Dengcun River. Male and female mosquitofish were captured at three sites contaminated by pulp and paper effluent in the Dengcun River in Sihui, South China, and at a nearby uncontaminated reference site. Samples were collected from the sampling sites on the same day in August 2009. We compared the populations by total length, wet body and liver mass, gonad mass, and population composition. We also compared the populations according to number of anal fin segments, oocyte and embryo count, anal fin and hemal spine morphology among females, and by sperm count and viability among males, and observed the gonadal and liver histology of both males and females. Female mosquitofish exposed to pulp and paper effluent in the Dengcun River were generally smaller in length and mass, had a greater number of anal fin segments and more embryos, but had significantly fewer oocytes in comparison with those living at the reference site. The higher number of anal fin ray 3 segments and the increased ray 4:6 length ratio observed among fish taken from the Dengcun River sites indicated that they might be subject to the androgenic effect. Furthermore, the significantly different hemal spine morphology of the effluent-affected females also indicated the pulp and paper mills effluents in Dengcun River might contain androgenic substance(s). Male mosquitofish at the sites exposed to effluent had a higher number of anal fin segments and greater testis mass in comparison with those living at the reference site. No evidence of intersex was found in either males or females, although histopathological tests on females revealed histologic abnormalities in the liver and gonads. It can be concluded that pulp and paper effluent contamination in the Dengcun River has affected a number of developmental parameters and reproductive characteristics in mosquitofish, with possible adverse effects on reproduction in this population.

Reproduction in Male Crotalus adamanteus Beauvois (Eastern Diamond-Backed Rattlesnake): Relationship of Plasma Testosterone to Testis and Kidney Dimensions and the Mating Season

The reproductive ecology of male Crotalus adamanteus Beauvois (Eastern Diamond-backed Rattlesnake) from southwestern Georgia (Joseph W. Jones Ecological Research Center, Baker County) was studied from 14 August 2003 to 14 August 2006. Few studies provide information on reproduction of free-living Eastern Diamondbacked Rattlesnakes, and no information is available on the seasonal relationship of plasma sex steroids of males to changes in the reproductive organs (e.g., mass of the testis and kidney) and the mating season. Here, the main goals were to determine whether: (i) males show variation in concentrations of plasma testosterone (T) during the active season (late March through November), (ii) males have elevated (peak) concentrations of plasma T during the single mating season, which has been documented to occur from late summer through early fall in nearby populations, and (iii) there are seasonal changes in length, width, and mass of the testis and kidney during the active season, particularly during the breeding period. There was a significant difference in mean concentrations of plasma T among seasons, with levels in summer significantly greater than those of spring, and levels in spring and fall were not significantly different. Testis mass and width, but not length, varied significantly across seasons. Testis mass paralleled elevated levels of plasma T, with peak mass occurring in the summer. Similarly, testis width was significantly greater in summer than in fall, but there was no significant difference between summer and spring, nor between spring and fall. We found no significant seasonal changes in any of the kidney measurements. Bisexual pairings were coincident or followed the occurrence of elevated levels of plasma T and changes in testis size; however, despite frequent observations, copulations were not observed. Nonetheless, our results support a mating season of late summer/early fall for the present population of Eastern Diamond-backed Rattlesnakes.

PREPARING TO HIBERNATE IN A DEEP FREEZE: ADRENAL ANDROGEN PRODUCTION IN SUMMER LINKED TO ENVIRONMENTAL SEVERITY IN WINTER IN ARCTIC GROUND SQUIRRELS

Event Abstract Back to Event PREPARING TO HIBERNATE IN A DEEP FREEZE: ADRENAL ANDROGEN PRODUCTION IN SUMMER LINKED TO ENVIRONMENTAL SEVERITY IN WINTER IN ARCTIC GROUND SQUIRRELS Rudy Boonstra1*, Adrian Bradley1, 2 and Brendan Delehanty1 1 University of Toronto Scarborough, Biological Sciences, Canada 2 University of Queensland,, School of Biomedical Sciences, Australia At high latitudes, evolutionary adaptations for winter focus on those that maximize survival, with hibernation being a major one used by many smaller mammals. Typically, mammalian hibernators overwinter in sites that are ≥ 0 °C. In the arctic, such sites do not exist. Lipid, the normal fuel of most hibernators, may not provide sufficient glucose needed by certain tissues to permit survival, with muscle breakdown being required. Critical to enhancing muscle stores are high concentrations of anabolic androgens at a time when the gonads are inactive. We compare arctic ground squirrels (AGS) from the Arctic and Columbian ground squirrel (CGS) from Alberta. In males, changes in testes mass over the active season were similar in AGS and CGS, being at a maximum prior to breeding, declining rapidly during the breeding period and, by late summer, being <10% of that at emergence. In contrast, during the breeding and pre-hibernation periods, levels in AGS were 6-10 and 20-25 times, respectively, those of CGS. From the breeding to the pre-hibernation periods, levels declined 41% in AGS, but 86% in CGS. In female AGS, androgen levels were high throughout the active season and, prior to hibernation, were 24 times those in female CGS. Androgen levels in both female and male AGS, decreased >10% in response to dexamethasone and increased >18% in response ACTH. These results implicate the adrenals as the source of the androgens. In male AGS, GnRH had no effect on androgen levels, whereas ACTH stimulated them by > 40%, both before and after gonadectomy. Adrenalectomy caused levels to fall by 80%. Thus, the adrenals, not the testes, are the source of the AGS androgens. We conclude that pre-hibernating AGS have evolved a solution seen in no other known mammal: exploiting the benefits of high adrenal androgen levels in nonbreeding animals to build muscle that is then catabolized overwinter. The unknown is how they have mitigated the costs of these steroids. (supported by NSERC grant to RB, Univ. Queensland grant to AJB, DINA grant to BD) Keywords: adrenal steroids, anabolic steroids, arctic climate, Hibernation, muscle anabolism and catabolism, seasonal reproductive status Conference: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology, Ann Arbor, United States, 13 Jul - 16 Jul, 2011. Presentation Type: Oral Presentation Topic: Environmental endocrinology Citation: Boonstra R, Bradley A and Delehanty B (2011). PREPARING TO HIBERNATE IN A DEEP FREEZE: ADRENAL ANDROGEN PRODUCTION IN SUMMER LINKED TO ENVIRONMENTAL SEVERITY IN WINTER IN ARCTIC GROUND SQUIRRELS. Front. Endocrinol. Conference Abstract: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology. doi: 10.3389/conf.fendo.2011.04.00006 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 11 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Dr. Rudy Boonstra, University of Toronto Scarborough, Biological Sciences, Toronto, Ontario, M1C 1A4, Canada, boonstra@utsc.utoronto.ca Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Rudy Boonstra Adrian Bradley Brendan Delehanty Google Rudy Boonstra Adrian Bradley Brendan Delehanty Google Scholar Rudy Boonstra Adrian Bradley Brendan Delehanty PubMed Rudy Boonstra Adrian Bradley Brendan Delehanty Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Relative testis size and mating systems in anurans: large testis in multiple-male mating in foam-nesting frogs

Abstract Comparative studies of the relative testes size in animals show that promiscuous species have relatively larger testes than monogamous species. Sperm competition favours the evolution of larger ejaculates in many animals – they give bigger testes. In the view, we presented data on relative testis mass for 17 Chinese species including 3 polyandrous species. We analyzed relative testis mass within the Chinese data set and combining those data with published data sets on Japanese and African frogs. We found that polyandrous foam nesting species have relatively large testes, suggesting that sperm competition was an important factor affecting the evolution of relative testes size. For 4 polyandrous species testes mass is positively correlated with intensity (males/mating) but not with risk (frequency of polyandrous matings) of sperm competition.

Is spermiogenesis common or rare in young male European bison aged 2 and 3 years?

The aim of the present study was to determine how often spermiogenesis occurs in young male European bison up to 3 years old. Research was performed on sections of the testes and epididymes collected from 51 male bison aged 2-3 years. The animals were divided into 2 age groups: young males up to 2 years and young males up to 3 years old, with further separation into specimens with or without spermiogenesis. The animals were culled during the autumn-winter seasons in 1994-2008 (after rutting period) in the Bialowieza Primeval Forest. Spermiogenesis in the 2-year-old animals was a rare condition found in 16.7% of cases. However, at the age of 3 years more than half of the individuals examined (53.3%) had spermiogenesis. Young males up to 2 years old with spermiogenesis were characterized by a significantly higher body weight and their right testis also weighed more than the left testis of the animals without spermiogenesis, the difference being on the border of statistical significance. There was no significant differences in the body mass and weight of the left testis between older animals, up to 3 years old, with or without spermiogenesis. However, young males up to 3 years old with spermiogenesis were characterized by a significantly higher weight of the right testis than those without spermiogenesis.

Reproductive biology of the lesser guitarfish Zapteryx brevirostris from the south-western Atlantic Ocean

This study provides the first detailed information on the reproductive biology of the lesser guitarfish Zapteryx brevirostris in the south-western Atlantic Ocean between latitudes 34° and 42° S. A total of 320 males (196-647 mm total length, L(T)) and 336 females (200-640 mm L(T)) were analysed. No significant differences were observed in size at 50% maturity between males (499 mm L(T)) and females (506 mm L(T)). Three seasonal patterns were related to the testes mass, the development of spermatocysts and the presence of spermatozoa in genital ducts. Females showed a 3 year reproductive cycle, with 2 years of ovarian maturation and 1 year of gestation, including a mean annual fecundity of one to two embryos. Synchronicity of both ovulating females and males with sperm in genital ducts indicated that ovulation and hence mating occurs during winter. Birth was assumed to occur during winter, but neither ovulation nor mating is simultaneous with this reproductive event. Despite its low economic value, a decline in abundance in the region, together with a low reproductive efficiency, indicates that the Z. brevirostris population should be monitored closely.

Natural history of dolphins of the genus Sotalia

General biology, including food habits, reproduction, age and health of the dolphins of the genus Sotalia, are reviewed according to current scientific knowledge. At least 25 teleost fish families, 5 cephalopod families and 1 crustacean family are included in the diet of the Guiana dolphin (S. guianensis), while up to 13 fish families were identified in the stomachs of the tucuxi (S. fluviatilis). Among the fish consumed by Sotalia spp., the schooling fish are the most common ones and both dolphin species use similar foraging strategies. However, due to the completely different ecosystems used by them, prey species consumed by these dolphins are also different. The maximum age of incidentally caught Guiana dolphin was 30yr and the maximum age estimated in the tucuxi was 43yr. The maximum total body length and weight reached by S. guianensis was 222cm and 121kg, respectively, and for S. fluviatilis 152cm and 53kg, respectively. Sexual maturity in the Guiana dolphin was estimated to occur at 170-180 cm in males, and 160-169 cm in females, while onset maturity in the tucuxi occurs at around 140cm in males and 132-137 cm in females. Ovulation apparently occurs only in the left ovary of the tucuxi, while both ovaries of the Guiana dolphins are functional. The proportion of testes mass in relation to total body mass in adult males can reach up to 5% in the tucuxi, and 3.3% in the Guiana dolphin, suggesting a promiscuous mating system with sperm competition in both species. Although seasonal birth peaks can occur in Guiana dolphins, they seem to reproduce throughout the year. However, the tucuxi presents defined birth seasonality, with most females giving birth during the low-water season in the Amazon. We suggest maintaining S. fluviatilis in the ‘Data Deficient’ category of the IUCN Red Data Book. Nevertheless, due to the recent recognition of S. guianensis as a species, its conservation status has not been assessed yet. This species, however, deserves special attention as it is strongly subjected to anthropogenic pressures throughout its distribution.

Unresolved abdominal mass in an adult cryptorchid testis: a case report

This case study aims to report an unresolved abdominal mass in an adult with cryptorchid testis and provide a review of related literature. We investigated a 54-year-old man who had cryptorchidism with a history of left orchiectomy 18 years prior. He was diagnosed with an intra-abdominal testicular mass after referring to the emergency ward with pelvic pain. The incidence of testicular cancer in undescended testicles is 40 times greater in the general population. In developed countries, the existence of undescended testicles in adult population is rare, which could be due to systematic practice of elective orchidopexy before the second year of life as well as orchiectomy in post-adolescent patients with undescended testicles. Despite these preventive measures, there are still some isolated cases of intra-abdominal testicular tumors in adults.

Larger testes are associated with a higher level of polyandry, but a smaller ejaculate volume, across bushcricket species (Tettigoniidae)

While early models of ejaculate allocation predicted that both relative testes and ejaculate size should increase with sperm competition intensity across species, recent models predict that ejaculate size may actually decrease as testes size and sperm competition intensity increase, owing to the confounding effect of potential male mating rate. A recent study demonstrated that ejaculate volume decreased in relation to increased polyandry across bushcricket species, but testes mass was not measured. Here, we recorded testis mass for 21 bushcricket species, while ejaculate (ampulla) mass, nuptial gift mass, sperm number and polyandry data were largely obtained from the literature. Using phylogenetic-comparative analyses, we found that testis mass increased with the degree of polyandry, but decreased with increasing ejaculate mass. We found no significant relationship between testis mass and either sperm number or nuptial gift mass. While these results are consistent with recent models of ejaculate allocation, they could alternatively be driven by substances in the ejaculate that affect the degree of polyandry and/or by a trade-off between resources spent on testes mass versus non-sperm components of the ejaculate.

Negative effect of the arthropod parasite, Sarcoptes scabiei, on testes mass in Iberian ibex, Capra pyrenaica

Testes mass is a key factor in male reproductive success and is potentially exposed to so-called ‘parasitic castration’. This is the result of the direct destruction or alteration of reproductive cell lineages (parasitic castration sensu stricto), or the indirect detrimental effects – for example, via body condition – on the ability of progenitors to produce or rear offspring (parasitic castration sensu lato). There are enormous gaps in our knowledge on the effects of parasites on the testes of wild mammals and in an attempt to rectify this dearth of data we examined the relationship between the skin parasite Sarcoptes scabiei and testes mass in Iberian ibex Capra pyrenaica. We considered data from 222 males that were culled in the population from the Sierra Nevada in Spain. Our results provide evidence that sarcoptic mange is associated with reduced size-corrected testes mass in Iberian ibex which supports the hypothesis that parasitism is a determining factor in gonad plasticity in male mammals. We discuss several hypothetical causes of this relationship and highlight the need to deepen the sub-lethal effects of pathogens if we are to accurately understand their modulator effects on host population dynamics.

Seasonal flexibility in organ size in the Andean lizard Liolaemus moradoensis

The understanding of animal functioning in fluctuating environments is a major goal of physiological and evolutionary ecology. In temperate terrestrial habitats, one of the most pervasive changes in environmental conditions is that associated with the seasonal change along the year. In this study, we describe the pattern of seasonal variation in the size of nine internal organs in the lizard Liolaemus moradoensis from the Andes Mountains of Central Chile. We observed that the size of digestive organs was greater during summer in comparison to other seasons. Dry masses of liver and fat bodies reached maximum values during summer and minimum during spring. We suspect that lowest spring values are related with build-up costs of energetically expensive organs (e.g., digestive, muscle mass) at the end of the hibernation period. Dry mass of the heart and lungs did not show a clear pattern of variation, suggesting that cardiac and pulmonary performance were maintained throughout the year. The dry mass of kidneys was greater during winter than during summer, a result observed in other hibernating lizards but for which there is no clear explanation. Finally, the dry mass of testes showed a maximum value during autumn and a progressive reduction toward summer, indicating that reproduction occurs during autumn. When represented in a bivariate space, acquisition (digestive), distribution (heart, lungs and kidneys), storage (liver and fat bodies), and expenditure (testes) organs generate four clusters. In general terms, observed seasonal pattern of change in organ size is in agreement with those reported for other lizard species that inhabit highly fluctuating environments.

Reproduction ofPtychoglossus bicolor(Squamata: Gymnophthalmidae) in an Andean Coffee Shade Plantation in Colombia

ABSTRACT. The pattern of annual reproductive activity and other reproductive characteristics were studied in a population of the gymnophthalmid lizard Ptychoglossus bicolor that inhabits the leaf-litter of an organic coffee shade plantation located on the Cordillera Oriental of the Colombian Andes. Males and females reached sexual maturity at a similar body size (approximately 45 mm snout vent length); however, adult males were significantly larger than females in body size, body mass, and head size. All adult males showed convoluted epididymides, enlarged testes with continuous spermatogenesis and spermiogenesis throughout the year. However, testis mass varied significantly among months and between seasons and was positively correlated with the amount of rainfall. Females were reproductively active (vitellogenic, ovigerous, and vitellogenic and ovigerous simultaneously) during all months of the year, and clutch size was always two. Abdominal fat bodies did not vary over time, neither in males nor in fema...

Reproductive Biology of Male Brown Treesnakes (Boiga irregularis) on Guam

Reproductive biology of males in the Guam population of the Brown Treesnake, Boiga irregularis, was investigated through monthly examinations of the urogenital system organs and plasma testosterone levels. All males examined during the 12 consecutive months of the study were spermatogenic and had sperm in the ductus epididymis and ductus deferens. No evidence of testicular recrudescence or regression was observed. Testis mass did not vary among months. Epithelial height of the kidney sexual segment was the only feature examined that varied significantly among months, with lowest heights observed in May through July. Despite this variation, the sexual segment in all males was hypertrophied and contained secretory granules. Plasma testosterone levels did not vary significantly among months, were relatively low compared to those of most other snake species, and were extremely variable among individuals. There were individuals with near-zero levels in most months. Overall, the reproductive biology of males on Guam is aseasonal. In light of this finding, the claim of seasonality in the putative source population is reassessed. Testosterone levels were independent of coelomic fat body mass, which was extremely variable among males and, in many cases, quite low. Observations on morphological features suggest that individual reproductive capacity increases disproportionately with increasing body size. The possibility of facultative aseasonal/seasonal reproduction in the species is discussed. The observed capacity for continuous spermatogenesis and its relative independence from body condition may facilitate the invasive capabilities of this ecologically damaging species.

Assessing the shape and topology of allometric relationships with body mass: a case study using testes mass allometry

Summary 1. Investigating allometric relationships is interesting in its own right as well as being important when controlling for the effects of body mass on specific structures in other areas of research. Here, I explore a number of basic assumptions behind the study of allometry and demonstrate that they are incorrect in theory and in practice for one commonly-studied allometric relationship, that between body mass and testes mass. 2. First, allometric relationships need not be linear. As a result, I recommend that the potential for nonlinearity should be considered and additive modelling (AM) or generalized additive modelling (GAM) used to explore this possibility before linear statistics are applied. In this respect, assessing and comparing the shape and the topology of allometric relationships are an important first step in any study which investigates or uses allometric relationships. This is particularly important when, as ecologists, we wish to control for the effects of allometry, where assuming linearity when it is not the case can lead to systematic, size-based biases in the results. 3. An extension of relaxing the assumption that allometric relationships must necessarily be linear is that the existence of nonlinear relationships means that allometric relationships for a given body mass range examined need not necessarily pass through the origin. This is because a nonzero intercept could indicate nonlinearity between the lowest body mass examined and a theoretical body mass of zero. 4. Finally, I show that allometric relationships identified using ratio data as the dependent variable are not necessarily biased. In particular, for testes mass allometry, when ratio data are log-transformed, the relationship obtained is topologically homologous to allometric relationships identified using log testes mass as the dependent variable. That is, both produce the same fitted values for testes mass from a given body mass. In addition, the same residual value for each data point is obtained in both cases. 5. A lack of awareness of these assumptions means that allometric relationships may be misunderstood, leading to a failure to account correctly for the effects of body mass in studies where this allometry needs to be controlled for.

Effects of season, age and body condition on allocation to testes mass in Iberian ibex

Sperm competition is a powerful evolutionary force, and understanding the factors that regulate testes characteristics may lead to a better understanding of the variability in male reproductive success. We explored the effects of age, body condition and season on relative testes mass in the Iberian ibex Capra pyrenaica. We analysed the variability of testes mass from 175 individuals, using a model selection approach based on Akaike's information criterion corrected for a small sample size. The results suggest that season, age and body condition influenced relative testes mass. Allocation to testes mass was greatest in the rutting season (autumn) and at ages that are associated with a subordinate status and a coursing, rather than mate-guarding, reproductive strategy. In addition, males in good condition had relatively heavier testes than those in poor condition. Thus, testes mass in Iberian ibex is governed by multiple factors, and this study leads to a better understanding of gonad plasticity in this polygamous ungulate. The effect of age matches the predictions from theoretical studies on sperm competition, which suggests greater allocation to testes in disadvantaged males.

Altered GABAAReceptor-Mediated Synaptic Transmission Disrupts the Firing of Gonadotropin-Releasing Hormone Neurons in Male Mice under Conditions That Mimic Steroid Abuse

Gonadotropin-releasing hormone (GnRH) neurons are the central regulators of reproduction. GABAergic transmission plays a critical role in pubertal activation of pulsatile GnRH secretion. Self-administration of excessive doses of anabolic androgenic steroids (AAS) disrupts reproductive function and may have critical repercussions for pubertal onset in adolescent users. Here, we demonstrate that chronic treatment of adolescent male mice with the AAS 17alpha-methyltestosterone significantly decreased action potential frequency in GnRH neurons, reduced the serum gonadotropin levels, and decreased testes mass. AAS treatment did not induce significant changes in GABAA receptor subunit mRNA levels or alter the amplitude or decay kinetics of GABAA receptor-mediated spontaneous postsynaptic currents (sPSCs) or tonic currents in GnRH neurons. However, AAS treatment significantly increased action potential frequency in neighboring medial preoptic area (mPOA) neurons and GABAA receptor-mediated sPSC frequency in GnRH neurons. In addition, physical isolation of the more lateral aspects of the mPOA from the medially localized GnRH neurons abrogated the AAS-induced increase in GABAA receptor-mediated sPSC frequency and the decrease in action potential firing in the GnRH cells. Our results indicate that AAS act predominantly on steroid-sensitive presynaptic neurons within the mPOA to impart significant increases in GABAA receptor-mediated inhibitory tone onto downstream GnRH neurons, resulting in diminished activity of these pivotal mediators of reproductive function. These AAS-induced changes in central GABAergic circuits of the forebrain may significantly contribute to the disruptive actions of these drugs on pubertal maturation and the development of reproductive competence in male steroid abusers.

Hip Injury - Football

HISTORY - A 21 year old college football player presents with increasing lower abdominal, right groin, and scrotal pain for 1 ½ years duration. He notes no initial trauma or sentinel event for the pain. Over the course of the next several months, the pain steadily increases and became more localized to his right hip/groin area. Patient noticed that the pain was exacerbated by running and sexual activity and radiated all over his pelvis and lower abdomen. PHYSICAL EXAMINATION: Examination revealed a soft, non-tender and non-distended abdomen without visible hernias, palpable masses, or hepatosplenomegaly. The musculoskeletal exam revealed no asymmetry and full flexion and extension of hips. However, decreased adduction and external rotation of the right hip with a negative Patricks test noted. Pt also had pain to palpation over pubic symphysis. Genital exam revealed normal genitalia, without hernia, testicular mass, lesion, or discharge. DIFFERENTIAL DIAGNOSIS Sports Hernia Varicocele/Hydrocele of Testis Sexually Transmitted Infection with Prostatitis/Epididymitis Labral tear of the hip Osteitis Pubis TEST AND RESULTS -U/S of groin/testes - revealed no visible hernias, nephrolithiasis, testicular or appendiceal torsion, varicocele, hydrocele, or mass of testis; however did show right spermatic cord swelling. -MRI Pelvis with and without contrast - 22mm right paralabral cyst and right superior labral tear. No hernia noted. -STI testing performed for Gonorrhea, Chlamydia, Syphilis, HIV, and Hepatitis panel negative on two separate occasions spaced out by 8 months in duration. FINAL/WORKING DIAGNOSIS - Right Labral cyst and Right acetabular labral tear. - Spermatic Cord Swelling. TREATMENT AND OUTCOMES -A series of steroid injections into the right hip using CT guidance to bridge to future hip arthroscopy for labral tear/cyst removal after football season has been completed. -Continue to be followed by athletic trainer for muscle strengthening exercises and stretches. -Scrotal support for spermatic cord swelling. -Returned to full workout routine and collegiate football within 4 weeks of steroid injection, muscle strengthening and stretching with full, painless range of motion, and able to meet the demands of his sport.

Immunocontraception in male feral swine treated with a recombinant gonadotropin-releasing hormone vaccine

Objective: To determine if a recombinant gonadotropin-releasing hormone (GnRH) vaccine is a potential immunocontraceptive agent for juvenile male feral swine. Materials and methods: At the beginning of the trial (Day 0) we treated animals in Treatment One with a single injection of a sham vaccine containing 1 mL of a buffer-adjuvant emulsion (adjuvant: AdjuVac; National Wildlife Research Center, Fort Collins, Colorado). Treatment Two received 1000 μg of a recombinant GnRH (rGnRH) vaccine (IMX294; Imaxio, Lyon, France). Treatment Three received 500 μg of a rGnRH vaccine. Treatment Four received 1000 μg of a GnRH vaccine (GonaCon; National Wildlife Research Center, Fort Collins, Colorado). On Day 90, Treatment Three received an additional 500-μg boost treatment. All vaccines were emulsified with AdjuVac and injected intramuscularly into the rump. On Day 180, we performed necropsies on swine and compared mass of testes, percent normal seminiferous tubules, numbers of spermatogonia, spermatocytes, and spermatids, serum testosterone levels, and anti-GnRH antibody titers among treatments. Results: As expected, a single dose of GonaCon vaccine reduced testes mass, serum testosterone, and percent normal tubules, and restricted sperm development at each stage. These reductions in reproductive development were associated with elevated GnRH antibodies. The single injection of rGnRH was not as effective in reducing these reproductive parameters; however, the two-dose injection of rGnRH was as effective as the single injection of GonaCon. Implication: Further research and development is needed into oral immunocontraceptive vaccines and oral delivery systems.