Testosterone Production In Males Research Articles

Testosterone and estradiol modify the expression of adhesins and biofilm formation in Actinobacillus seminis.

Actinobacillus seminis is the causal agent of epididymitis and has other effects on the reproductive tracts of small ruminants and bovines. This bacterium causes infection when luteinizing (LH) or follicle-stimulating hormones increase, and hosts reach sexual maturity. LH induces female ovulation and male testosterone production, suggesting that these hormones affect A. seminis pathogenicity. In the present study, we evaluated the effect of testosterone (1-5ng/ml) or estradiol (5-25 pg/ml) added to culture medium on the in vitro growth, biofilm production, and adhesin expression of A. seminis. Estradiol does not promote the growth of this bacterium, whereas testosterone increased A. seminis planktonic growth 2-fold. Both hormones induced the expression of the elongation factor thermo unstable (EF-Tu) and phosphoglycerate mutase (PGM), proteins that A. seminis uses as adhesins. Estradiol (5 or 10 pg/ml) decreased biofilm formation by 32%, whereas testosterone, even at 5ng/ml, showed no effect. Both hormones modified the concentrations of carbohydrates and eDNA in biofilms by 50%. Amyloid proteins are characterized by their capacity to bind Congo red (CR) dye. Actinobacillus seminis binds CR dye, and this binding increases in the presence of 5-20 pg/ml estradiol or 4ng/ml testosterone. The A. seminis EF-Tu protein was identified as amyloid-like protein (ALP). The effect of sexual hormones on the growth and expression of virulence factors of A. seminis seems to be relevant for its colonization and permanence in the host.

Medicinal Properties of Zingiber officinale

Zingiber officinale stands in the family Zingiberaceae. Ginger has rich phytochemistry plays a very pivotal role in health promotion. This research is aimed to review the current evidence on the various medicinal properties of ginger. Ginger is known to exert a wide range of pharmacological as well as physiological activities. Since time immemorable, it has been in use for the medicaments of various illnesses, like colds, headache, sore throat, migraines, hypertension, arthritis. Owing to this, this plant's pharmacological and medicinal properties have been a popular topic of review and research. This herb shows several puissant preventive and therapeutic actions and finds its extensive usage for ages to the present day for numerous ailments. Ginger exhibits potent anti-inflammatory and analgesic effects, which help decrease swelling, pain, and inflammation. One of the known and the most frequent usage of ginger has been to relieve the patients of nausea and vomiting. Ginger works as an antiemetic and is recommended to prevent sea sickness and motion sickness. It relieves motion sickness more effectively than specific drugs. Zingiber officinale has been identified to reduce pain. Ginger powder plays an influential role in mitigating the symptoms of primary dysmenorrhea. Experimental studies have confirmed ginger’s role in reducing blood glucose levels improvement of hyperlipidemia. Ginger extract has been instrumental in reducing the structural abnormalities of heart in diabetic and helps improve the levels of serum apo, cathepsin G, leptin, Hcy and with anti oxidative effects of extract from ginger. Ginger supplementation enhances testosterone production in males, particularly in oxidative stress conditions.

The AP-1 family of transcription factors are important regulators of gene expression within Leydig cells.

Members of the AP-1 family of transcription factors are immediate early genes being modulated by different extracellular signals. The aim of this review is to highlight the important roles of AP-1 members in transcriptional regulation of genes important for testicular Leydig cell function and male testosterone production. A search of the relevant literature was performed in Google Scholar and NCBI Pubmed for AP-1 members and Leydig cells. Additional information was accessed from references of relevant articles. Only primary data from original peer-reviewed articles was considered for this review. Different signaling pathways important for Leydig cells' functions are involved in the regulation of the activity of AP-1 members. These transcription factors participate in the regulation of genes related to different biological processes important for Leydig cells. We conclude that members of the AP-1 family of transcription factors play critical roles in the regulation of Leydig cell proliferation, steroidogenesis, and cell-to-cell communication.

The Impact of Transforming Growth Factor-b1 on the men infertility

The influence of cytokines in the reproductive system is becoming increasingly important. The major cytokines involved in the proliferative system are TGFβ-1 that performs many cellular functions, including controlling cell growth, cell proliferation, cell differentiation and apoptosis. Current information indicates a close interrelationship between immune and reproductive functions resulting from the participation of certain cytokines and their receptors. Cytokine-converting growth factor-b (TGF-b) is initially purified from human platelets, a rich source of this protein. In addition to platelets, TGF-b1 is also generated in other blood elements from these elements plasma (semen plasma) and circulating white blood cells. However, more than many years after the initial isolation of TGF-b1, there is no consensus on the amount of TGF-b1 present in normal human plasma. TGFb1 is considered as a critical regulator of reproductive tissue development and characteristic cyclic modification. The physiological significance of TGFb1 in reproductive biology and productivity has been extensively examined in Tgfb1 null mutant mice. Genetic deficiency of TGFb1 disrupts the functioning of the hypothalamic-pituitary-gonadal axis, inhibiting luteinizing hormone (LH) synthesis and leading to subsequent effects on testosterone production in males. These studies demonstrate the profound importance of TGFb1 in males and provide a basis for exploring the importance of this cytokine in Human infertility and sexual dysfunction.

PD30-09 WHAT IS A NORMAL TESTOSTERONE FOR MEN <45 YEARS OLD? RETHINKING THE 300NG/DL CUTOFF FOR HYPOGONADISM

You have accessJournal of UrologySexual Function/Dysfunction: Evaluation II (PD30)1 Sep 2021PD30-09 WHAT IS A NORMAL TESTOSTERONE FOR MEN <45 YEARS OLD? RETHINKING THE 300NG/DL CUTOFF FOR HYPOGONADISM Alexander Zhu, Juan Andino, Stephanie Daignault-Newton, Zoey Chopra, Aruna Sarma, and James M. Dupree Alexander ZhuAlexander Zhu More articles by this author , Juan AndinoJuan Andino More articles by this author , Stephanie Daignault-NewtonStephanie Daignault-Newton More articles by this author , Zoey ChopraZoey Chopra More articles by this author , Aruna SarmaAruna Sarma More articles by this author , and James M. DupreeJames M. Dupree More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002031.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: There is an age-related decline in male testosterone production. It is therefore surprising that younger men are evaluated for hypogonadism with the same cutoff of 300ng/dl that was originally developed from samples of older men. Our aim is to describe normal testosterone levels in 20-44 year old men from a national survey. METHODS: We analyzed data from the 2011−2016 National Health and Nutrition Examination Surveys (NHANES) from the Centers for Disease Control, which surveys a nationally representative sample of US residents. Men between 20 to 44 years old were included. Men on hormonal medications, those with a history of testicular cancer, and men with afternoon or evening blood draws were excluded. We separated men into five-year age intervals (20-24, 25-29, 30-34, 35-39 and 40-44 years old) and categorized testosterone levels for men of each age group (mean, 2.5th, 5th, 10th, 25th, 50th 75th and 90th percentile). We determined the proportion of men in each age group that fell below the 300ng/dL cutoff for hypogonadism and would typically meet the threshold for having low testosterone. We further characterized the relationship of testosterone levels in young men to BMI, diabetes, and smoking. RESULTS: 1,486 men 20 to 44 years old had morning testosterone levels available for review. Morning testosterone distributions are described in Tables 1 and 2. Men with BMI <25 had testosterone levels 241ng/dL higher than those with BMI >40+ (p<0.0001). Men with diabetes had lower testosterone levels by 72.7ng/dL (p<0.0001). Daily smokers had testosterone levels that were 56ng/dL higher than nonsmokers (p<0.0001). CONCLUSIONS: This is the first study to evaluate testosterone levels for men younger than 45 years of age. We provide age-adjusted “normal” testosterone values for clinicians to use in counseling younger men presenting with hypogonadism. Specifically, younger hypogonadal men will now have a framework with which to compare their testosterone levels to age-matched peers. Source of Funding: N/A © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e535-e536 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alexander Zhu More articles by this author Juan Andino More articles by this author Stephanie Daignault-Newton More articles by this author Zoey Chopra More articles by this author Aruna Sarma More articles by this author James M. Dupree More articles by this author Expand All Advertisement Loading ...

Ablation of the canonical testosterone production pathway via knockout of the steroidogenic enzyme HSD17B3, reveals a novel mechanism of testicular testosterone production.

Male development, fertility, and lifelong health are all androgen‐dependent. Approximately 95% of circulating testosterone is synthesized by the testis and the final step in this canonical pathway is controlled by the activity of the hydroxysteroid‐dehydrogenase‐17‐beta‐3 (HSD17B3). To determine the role of HSD17B3 in testosterone production and androgenization during male development and function we have characterized a mouse model lacking HSD17B3. The data reveal that developmental masculinization and fertility are normal in mutant males. Ablation of HSD17B3 inhibits hyperstimulation of testosterone production by hCG, although basal testosterone levels are maintained despite the absence of HSD17B3. Reintroduction of HSD17B3 via gene‐delivery to Sertoli cells in adulthood partially rescues the adult phenotype, showing that, as in development, different cell‐types in the testis are able to work together to produce testosterone. Together, these data show that HS17B3 acts as a rate‐limiting‐step for the maximum level of testosterone production by the testis but does not control basal testosterone production. Measurement of other enzymes able to convert androstenedione to testosterone identifies HSD17B12 as a candidate enzyme capable of driving basal testosterone production in the testis. Together, these findings expand our understanding of testosterone production in males.

SUN-040 Hormone Replacement Therapy in Transgender Unmasks Testicular Tumor

Introduction In transwomen, hormonal replacement therapy typically usually consists of anti-androgen and/or estrogens. Per Endocrine Society 2017 guidelines, patients should be evaluated every 3 months in the first year for appropriate signs of feminization and adverse reactions. This includes measuring serum testosterone every 3 months initially and the testosterone level should be < 50 ng/dL. We describe a case of a transwoman patient diagnosed with testicular seminoma during surveillance of hormonal replacement therapy (HRT). Case presentation A 31-year-old male-to-female transgender presents to the endocrine clinic for HRT. She previously had seen another provider for HRT and was started on estradiol valerate 5 mg weekly and leuprolide 3.75 mg every month. After 5 months of therapy, she reported that her testosterone level remained elevated, so spironolactone 100 mg BID was subsequently added. Despite adherence, she was dismayed at how little physical changes she achieved after 1.5 years of HRT. She denies taking exogenous substances or OTC mediation containing androgens. Her examination reveals a male habitus and musculature with male voice, male diamond pubic hair pattern, adult penis size and scrotum measuring 20 cc’s bilaterally. Initial labs revealed total testosterone 131 ng/dl, free testosterone 30.8 ng/dl, bioavailable testosterone 64.6 ng/dl, SHBG 12 nmol/L, LH < 0.07 IU/L, FSH < 0.1 IU/L, and estradiol 146 pg/ml. Due to non-suppressed testosterone level despite undetectable gonadotropins, adrenal androgen labs were obtained which was normal. However, her HCG-beta tumor marker was elevated, 12 IU/L (0-3). This prompted a scrotal ultrasound which revealed 3.2 cm right testis mass. Follow-up PET/CT revealed increased activity localized to the right testis without findings of metastasis. Patient underwent right orchiectomy with pathology revealing seminoma stage 1A pT1bMx. At 2 months postop, her total testosterone is now 8 ng/dl, and she reports that her breast tissue has increased and skin softened. Conclusion Hyperandrogenism can be easily diagnosed in females given more obvious clinical features; however, except for precocious puberty, there are typically no obvious features of exogenous testosterone production in males. Thus, typically no workup is undertaken in males to look for underlying cause, including testicular cancer. While presence of scrotal mass is the most common initial presentation, patients can be asymptomatic until tumor burden is high and there is metastasis. Transwomen should be monitored by obtaining estradiol and testosterone levels following the Endocrine Society guidelines. If patient is on GnRH agonist, her testosterone level should be almost completely suppressed (T <50). A testosterone level > 50 ng/dL while on GnRH therapy should warrant workup for exogenous sources, including testicular cancer and adrenal abnormalities.

Osteocalcin as a Biomarker for Estimation of Infertility for Iraqi Patients

Objective: The evaluation of serum osteocalcin (OSN) for Iraqi infertile patients to see the effect of osteocalcin insufficiency, which may lead to a decreased level of testosterone production in males that may cause infertility. Methods: Forty two newly diagnosed infertile males age range (24–47) years and thirty two apparently healthy males as controls age range (25–58) years. Serum levels of testosterone (TEST), stimulating follicle hormone (FSH) and luteinizing hormone (LH), prolactin (PROL), osteocalcin OSN, and fasting blood sugar (FBS) were performed in both patients and controls. Estimation of serum OSN by Immulite1000 auto-analyzer, TEST, FSH, LH, PROL, and FBS by Immulite2000 auto-analyzer. Results: Infertile patients show significantly elevated serum levels for follicle-stimulating hormone (FSH), LH, and PROL as compared with controls according to p-value ( 0.000), (0.044), and (0.000), respectively. On the other hand, the infertile patients have lowered serum levels for OSN and TEST as compared with controls according to p-value (0.000) and (0.000), respectively. Fasting blood sugar (FBS) is evaluated within the normal levels for both patients and control groups. Conclusion: Osteocalcin, act as a regulator of male fertility via its role in the biosynthesis of testosterone, so it serves as a biomarker for evaluation of male infertility. Therefore, osteocalcin could be used as a therapeutic for the treatment of disorders related to male reproduction, including male infertility and low testosterone levels.

Sex differences in infant body composition emerge in the first 5 months of life.

Background Sex differences in body composition are appreciated throughout the lifespan with probable contributions from sex steroids: testosterone and estrogen. The purpose of this longitudinal observational study was to determine if sex differences in body composition emerge during the first months of life in healthy infants, corresponding to the age at which male infants produce endogenous testosterone. Methods Linear growth and body composition parameters using air displacement plethysmography were obtained from 602 healthy infants after birth and again at 5 months of age. Rate of change in body composition parameters were compared between sexes. Results Sex differences in length, total mass, fat free mass (FFM), and percent fat mass (%FM) were present both at birth and at 5 months (p < 0.001 for all), with males having greater total mass and FFM but lower %FM. Gain in %FM over the first 5 months was significantly lower in males (p = 0.0004). This difference was secondary to a gain of 17 g/week more in FFM in males compared to females. Conclusions Sex differences in body composition emerge in the first months of life, with lower adiposity accumulation in males. Endogenous testosterone production in males ~1-4 months of age may account for findings and may have lifelong implications for sex differences in body composition.

Effect of Coenzyme Q10 Supplementation on Testosterone.

Enhancing testosterone production in males is a continuous research direction for many scientists in the field, due to its role as a principal sex hormone and as a crucial modulator of well-being and general health in humans. Since 1978, there have been more than 30 studies that have connected coenzyme Q10 and testosterone. Such a link is attributable to the vigorous biological role of coenzyme Q10 as a crucial member in the energy production route in humans and animals, which is thought to have a positive influence on testosterone production, and hence on infertility, particularly male infertility. However, this connection has not yet been deliberated. The present work systematically reviews and summarizes the influence of coenzyme Q10 supplementation on testosterone. To accomplish this purpose, the Scopus, PubMed, and Web of Science databases were searched using the keywords “coenzyme Q10” versus “testosterone” for English language papers from November 1978 through October 2018. Relevant articles were also discussed and included to address an integral discussion. In summary, to date the studies conducted on human males reveal insignificant effects of coenzyme Q10 supplementation on testosterone. Similarly, rather than the reproductive toxicity studies, the studies conducted on animals did not show any positive influence of coenzyme Q10 on testosterone. However, coenzyme Q10 supplementation was found to ameliorate the reduction in testosterone induced by chemical reproductive toxicants, mainly by neutralizing the damaging effect of the generated free radicals. However, collectively these findings require further confirmation by additional research studies.

Ginger and Testosterone.

Enhancing and protecting testosterone production is one target for many scientists because of its crucial role as a primary sex hormone in males. Several in vivo trials have utilized different dietary supplements and medicinal plants to enhance testosterone production in males. Since 1991, various in-vivo, as well as basic research studies, have discovered a link between ginger (Zingiber officinale) and testosterone. However, such a link has not yet been collectively reviewed. This review systematically discusses and summarizes the effect of ginger and ginger extracts on testosterone. To achieve this contribution, we searched the PubMed, Scopus, and Web of Science databases for English language articles (full texts or abstracts) from November 1991 through August 2018 using the keywords “ginger” and “Zingiber officinale” versus “testosterone”. Additionally, the references from related published articles were also reviewed, only if relevant. In conclusion, the mainstream of research that links ginger to testosterone demonstrated that ginger supplementation, particularly in oxidative stress conditions, enhances testosterone production in males. The mechanisms by which this occurs mainly by enhancing luteinizing hormone (LH) production, increasing the level of cholesterol in the testes, reducing oxidative stress and lipid peroxidation in the testes, enhancing the activity of the antioxidant enzymes, normalizing blood glucose, increasing blood flow in the testes, increasing testicular weight, and recycling testosterone receptors. However, the effect of ginger on testosterone is not yet confirmed in humans. Therefore, clinical studies in this context of research are imperative.

Serum chemerin levels are negatively associated with male fertility and reproductive hormones.

Are chemerin levels different in subfertile men compared to men from the general population, and how does chemerin relate to reproductive hormonal status? Chemerin is negatively associated to LH, SHBG and estradiol and lower levels of chemerin are detected among subfertile men compared to controls. Adipokines have pleiotropic effects on tissue homeostasis and have been shown to affect both sex steroid production and action. Among adipokines the newly characterized chemokine chemerin is suggested to influence testosterone production in males, but whether serum levels associate with testosterone or male subfertility has not yet been reported. Case control study comprising a consecutive group of men from infertile couples referred to Reproductive Medicine Centre at Skane University Hospital from 2006 through 2012, and age-matched controls. Participants were enrolled in years 2011-2013. Males from infertile couples (n = 180) aged 18-50 years with sperm concentration <20 × 106/ml and age-matched controls (n = 139) from the general population were enrolled. Serum concentrations of total testosterone (TT), calculated free testosterone (cFT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2) and sex-hormone binding globuline (SHBG) as well as the adipokines chemerin, adiponectin and leptin were measured. Anthropometrics and biochemical parameters of glucose and lipid metabolism were assessed. Chemerin levels were lower in subfertile men compared to controls (mean diff. 7.1 ng/ml; 95% CI, 3.7; 11 ng/ml; P < 0.001) even after adjustment for BMI. After adjustment for age, BMI, smoking, leptin and adiponectin, chemerin associated negatively with LH (ß = -4.2; P = 0.02), E2 (ß = -10; P = 0.004) and SHBG (ß = -7.4, P = 0.003). Men with elevated LH levels had lower chemerin levels compared to those with LH levels within the normal range (mean diff. 4.8 ng/ml; 95% CI, 0.16; 9.4 ng/ml; P = 0.04). Single sample blood test with immunoassays for determination of hormone levels. Heterogeneous group of subfertile subjects. Even though chemerin has been positively associated with BMI, inverse association with subfertility suggests that it is independently linked to reproductive function, a hypothesis that warrants further assessment. This work was supported by grants from EU Interreg V (ReproUnion) program as well as Swedish Governmental Fund for Clinical Research. The authors have no conflicts of interest.

Effects of different dietary DHA:EPA ratios on gonadal steroidogenesis in the marine teleost, tongue sole (Cynoglossus semilaevis).

The present study was conducted to investigate the effects of dietary DHA and EPA on gonadal steroidogenesis in mature females and males, with a feeding trial on tongue sole, a typical marine teleost with sexual dimorphism. Three experimental diets differing basically in DHA:EPA ratio, that is, 0·68 (diet D:E-0·68), 1·09 (D:E-1·09) and 2·05 (D:E-2·05), were randomly assigned to nine tanks of 3-year-old tongue sole (ten females and fifteen males in each tank). The feeding trail lasted for 90 d before and during the spawning season. Fish were reared in a flowing seawater system and fed to apparent satiation twice daily. Compared with diet D:E-0·68, diet D:E-1·09 significantly enhanced the oestradiol production in females, whereas diet D:E-2·05 significantly enhanced the testosterone production in males. In ovaries, diet D:E-1·09 induced highest mRNA expression of follicle-stimulating hormone receptor (FSHR), steroidogenic acute regulatory protein, 17α-hydroxylase (P450c17) and 3β-hydroxysteroid dehydrogenase (3β-HSD). In testes, diet 2·05 resulted in highest mRNA expression of FSHR, cholesterol side-chain cleavage enzyme, P450c17 and 3β-HSD. Fatty acid profiles in fish tissues reflected closely those of diets. Female fish had more gonadal EPA content but less DHA content than male fish, whereas there was a reverse observation in liver. In conclusion, the dietary DHA:EPA ratio, possibly combined with the dietary EPA:arachidonic acid ratio, differentially regulated sex steroid hormone synthesis in mature female and male tongue soles. Females seemed to require more EPA but less DHA for the gonadal steroidogenesis than males. The results are beneficial to sex-specific nutritive strategies in domestic teleost.

Sex differences and sex hormones in anxiety-like behavior of aging rats

Sex differences in the prevalence of affective disorders might be attributable to different sex hormone milieu. The effects of short-term sex hormone deficiency on behavior, especially on anxiety have been studied in numerous animal experiments, mainly on young adult rats and mice. However, sex differences in aged animals and the effects of long-term hypogonadism are understudied. The aim of our study was to analyze sex differences in anxiety-like behavior in aged rats and to prove whether they can be attributed to endogenous sex hormone production in males. A battery of tests was performed to assess anxiety-like behavior in aged female, male and gonadectomized male rats castrated before puberty. In addition, the aged gonadectomized male rats were treated with a single injection of estradiol or testosterone or supplemented with estradiol for two-weeks. Female rats displayed a less anxious behavior than male rats in most of the conducted behavioral tests except the light-dark box. Long-term androgen deficiency decreased the sex difference in anxiety either partially (open field, PhenoTyper cage) or completely (elevated plus maze). Neither single injection of sex hormones, nor two-week supplementation of estradiol in gonadectomized aged male rats significantly affected their anxiety-like behavior in the elevated plus maze. In conclusion, our results confirm sex differences in anxiety in aged rats likely mediated by endogenous testosterone production in males. Whether long-term supplementation with exogenous sex hormones could affect anxiety-like behavior in elderly individuals remains to be elucidated.

Dietary arachidonic acid differentially regulates the gonadal steroidogenesis in the marine teleost, tongue sole (Cynoglossus semilaevis), depending on fish gender and maturation stage

A 3-month feeding trial with tongue sole Cynoglossus semilaevis broodstock was conducted before and during the spawning season to investigate the effects of dietary arachidonic acid (ARA) on the production of sex steroid hormones and gonadal gene expression of key proteins in steroidogenesis. Three isonitrogenous and isolipidic experimental diets were formulated to contain different ARA levels: the control diet without ARA supplementation (C, 0.58% ARA of total fatty acids (TFA)) and two diets with low (5.14% of TFA, ARA-L) or high ARA (15.44% of TFA, ARA-H) supplementation. The diets were randomly assigned to 9 tanks of 3-year-old tongue sole (10 females and 15 males in each tank). Fish were reared in a flowing seawater system and fed to apparent satiation twice daily. At the end of the feeding trial, tissue samples from mature females (MF, with spontaneous ovulation), immature females (IMF, early vitellogenesis), and mature males (MM, expressing milt) were collected to assay the production of sex steroid hormones, gonadal gene expression of sex steroid-synthesizing proteins, as well as the fatty acid profiles of gonad, liver and muscle lipids. Results showed that ARA supplementation significantly reduced the estradiol production in females, but stimulated the testosterone production in males. ARA supplementation significantly reduced the mRNA expression of aromatase in ovaries but significantly increased the gene expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) in testes. In mature ovaries, diet ARA-L significantly reduced the gene expression of follicle stimulating hormone receptor (FSHR), 3β-HSD, and 17β-HSD; however, in immature ovaries, it significantly increased the gene expression of FSHR, steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450ssc), 3β-HSD, and 17β-HSD. In all gonads, 17α-hydroxylase (P450c17) responded to dietary ARA differently from other sex steroid-synthesizing proteins. ARA was preferentially accumulated in tongue sole gonad lipids. ARA concentrations were highest in gonad, liver and muscle lipids of MM fish and lowest in MF fish. Compared to female tongue sole, males had higher DHA concentrations in gonad lipids, but lower concentrations in liver lipids. In conclusion, results suggest dietary ARA regulates sex steroid hormone synthesis in tongue sole broodstock, and accumulates in gonad lipids, depending on both fish gender and maturation stage. Dietary ARA supplementation appears more important for male fish than for female fish, and more important for immature females than for mature females. Statement of relevanceThis study is beneficial to the broodstock diet formulation.

Effect of Vincristine on Steroidogenic Pathway of Male Wistar Rat

Vincristine is major player in front line combination chemotherapy for treatment of cancer and shows decrease in testosterone after treatment contributing to reproductive toxicity. Hence, the present research was aimed to study the effect of vincristine on steroidogenic pathway which is responsible for testosterone production in males. Vincristine was intraperitoneally injected to adult male Wistar rats of proven fertility with a dose of 40μg/kg/day dissolved in 0.5 ml of physiological saline for 30 days. Animals were sacrificed at the end of treatment period; their testes were removed and used for further studies. No significant changes were observed in body weight, testis weight and mean relative testis weight. Expression studies of enzymes involved in steroidogenic pathway showed that there was decrease in expression of Steroidogenic acute regulatory (StAR) protein which might be responsible for altered testosterone production.

Novel insights in the regulation and mechanism of androgen action on bone

This review provides an update on the associations of testosterone, estrogens, sex hormone binding globulin, GH-IGF-I, osteocalcin and mechanical loading with relevance to skeletal health. The simple concept of a dual model of action of androgens, i.e. either directly via the androgen receptor or indirectly by estrogens, is proving more complicated because of novel interactions of these hormones and their receptors with other hormonal as well as mechanical signals. Testosterone - in contrast with estrogen - is not uniformly associated with fracture risk in men. However, androgen receptor mediated action is clearly important for trabecular bone maintenance in male mice whereas both estrogens and androgens regulate cortical bone growth. The osteoblast and osteocyte appear to be involved in such androgen receptor mediated action on bone in male mice. Studies in mice also showed an unexpected interaction between osteocalcin and testosterone production in males and, vice versa, between ovarian production of follicle-stimulating hormone with testosterone and potentially bone formation.

Tissue-specific expression of squirrel monkey chorionic gonadotropin

Pituitary gonadotropins LH and FSH play central roles in reproductive function. In Old World primates, LH stimulates ovulation in females and testosterone production in males. Recent studies have found that squirrel monkeys and other New World primates lack expression of LH in the pituitary. Instead, chorionic gonadotropin (CG), which is normally only expressed in the placenta of Old World primates, is the active luteotropic pituitary hormone in these animals. The goal of this study was to investigate the tissue-specific regulation of squirrel monkey CG. We isolated the squirrel monkey CGβ gene and promoter from genomic DNA from squirrel monkey B-lymphoblasts and compared the promoter sequence to that of the common marmoset, another New World primate, and human and rhesus macaque CGβ and LHβ. Using reporter gene assays, we found that a squirrel monkey CGβ promoter fragment (−1898/+9) is active in both mouse pituitary LβT2 and human placenta JEG3 cells, but not in rat adrenal PC12 cells. Furthermore, within this construct separate cis-elements are responsible for pituitary- and placenta-specific expression. Pituitary-specific expression is governed by Egr-1 binding sites in the proximal 250bp of the promoter, whereas placenta-specific expression is controlled by AP-2 sites further upstream. Thus, selective expression of the squirrel monkey CGβ promoter in pituitary and placental cells is governed by distinct cis-elements that exhibit homology with human LHβ and marmoset CGβ promoters, respectively.

Inhibition of 3β- and 17β-hydroxysteroid dehydrogenase activities in rat Leydig cells by perfluorooctane acid

Perfluorooctane acid (PFOA) is classified as a persistent organic pollutant and as an endocrine disruptor. The mechanism by which PFOA causes reduced testosterone production in males is not known. We tested our hypothesis that PFOA interferes with Leydig cell steroidogenic enzymes by measuring its effect on 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) activities in rat testis microsomes and Leydig cells. The IC 50s of PFOA and mode of inhibition were assayed. PFOA inhibited microsomal 3β-HSD with an IC 50 of 53.2 ± 25.9 μM and 17β-HSD3 with an IC 50 17.7 ± 6.8 μM. PFOA inhibited intact Leydig cell 3β-HSD with an IC 50 of 146.1 ± 0.9 μM and 17β-HSD3 with an IC 50 of 194.8 ± 1.0 μM. The inhibitions of 3β-HSD and 17β-HSD3 by PFOA were competitive for the substrates. In conclusion, PFOA inhibits 3β-HSD and 17β-HSD3 in rat Leydig cells.

Longitudinal monitoring of fecal testosterone in male Malayan Sun bears (U. malayanus)

Fecal steroid monitoring was applied as a non-invasive method to investigate testicular cycles and seasonality in the Malayan Sun bear (Ursus malayanus), an endangered ursid from South East Asia. Fecal testosterone was analyzed by radioimmunoassay in samples collected from male Sun bears (n=8) housed in zoological parks in North America and New Zealand, over periods of 0.05). All bears did, however, share a common pattern of annual excretion that suggests a potential role for non-photoperiodic seasonal influences on testicular cycles. Levels were generally lower early in the year with regular increases occurring at 3–4-month intervals. Grouped data suggest an association between cycles of testosterone production in males and months of peak reproductive activity in captivity. Zoo Biol 0:1–15, 2005. © 2005 Wiley-Liss, Inc.