Increase In Serum Testosterone Concentrations Research Articles

Bezafibrate alleviates diabetes-induced spermatogenesis dysfunction by inhibiting inflammation and oxidative stress

The metabolic disorders caused by diabetes can lead to various complications, including male spermatogenesis dysfunction. Exploring effective therapeutics that attenuate diabetes mellitus (DM)-induced male subfertility is of great importance. Pharmaceuticals targeting PPARα activation such as bezafibrate have been regarded as an important strategy for patients with diabetes. In this study, we use streptozocin (STZ) injection to establish a type 1 DM mice model and use bezafibrate to treat DM mice and evaluate the effects of bezafibrate on the spermatogenic function of the DM male mice. Bezafibrate treatment exhibited protective effects on DM-induced spermatogenesis deficiency, as reflected by increased testis weight, improved histological morphology of testis, elevated sperm parameters, increased serum testosterone concentration as well as increased mRNA levels of steroidogenesis enzymes. Meanwhile, testicular cell apoptosis, inflammation accumulation and oxidative stress status were also shown to be alleviated by bezafibrate compared with the DM group. In vivo and in vitro studies, PPARα specific inhibitor and PPARα knockout mice were further used to investigate the role of PPARα in the protective effects of bezafibrate on DM-induced spermatogenesis dysfunction. Our results indicated that the protection of bezafibrate on DM-induced spermatogenesis deficiency was abrogated by PPARα inhibition or deletion. Our study suggested that bezafibrate administration could ameliorate DM-induced spermatogenesis dysfunction and may represent a novel practical strategy for male infertility.

The Effect of Melissa officinalis Hydro Alcoholic Extract on Liver Enzymes, Markers of Kidney Function and Testosterone in Lead Poisoned Rats

Background: Lead, one of the most important environmental pollutants, can induce a broad range of physiological dysfunction. The aim of this study was to investigate the protective effect of the Melissa officinalis plant extract on biomarkers of liver and kidney function as well as serum testosterone concentration in lead-exposed male rats. Methods: We used 40 Wistar rats and divided them into 5 groups. The control group received saline (1 mL/kg) by gastric gavage and 30 minutes later received saline (1 mL/kg) through i.p injection. The lead group received saline (1 mL/kg) by gastric gavage and 30 minutes later received i.p injection of lead acetate (20 mg/kg). The treatment groups received different doses of M. officinalis alcoholic extract (20, 100, and 500 mg/kg, respectively) by gastric gavage and 30 min later received i.p injection of lead acetate (20 mg/kg). The rats were treated for 5 days and then twenty -four hours after the last injection, blood samples were collected for the measurement of urea, creatinine, uric acid, alanine transaminase (ALT), alkaline phosphatase (ALP), aspartate transaminase (AST) and testosterone. Data analysis was performed through SPSS (version 16). Results: Melissa extract (100 mg/kg) significantly reduced liver enzymes and kidney function markers when compared to the lead group. Treatment with Melissa extract (100 mg/kg and 500 mg/kg) significantly increased serum testosterone concentration compared to the lead group. Conclusion: The biochemical results of this study showed that M. officinalis may be beneficial in lead-induced liver and kidney dysfunction.

High-fidelity reprogramming into Leydig-like cells by CRISPR activation and paracrine factors.

Androgen deficiency is a common medical conditions that affects males of all ages. Transplantation of testosterone-producing cells is a promising treatment for male hypogonadism. However, getting a cell source with the characteristics of Leydig cells (LCs) is still a challenge. Here, a high-efficiency reprogramming of skin-derived fibroblasts into functional Leydig-like cells (LLCs) based on epigenetic mechanism was described. By performing an integrated analysis of genome-wide DNA methylation and transcriptome profiling in LCs and fibroblasts, the potentially epigenetic-regulating steroidogenic genes and signaling pathways were identified. Then by using CRISPR/dCas9 activation system and signaling pathway regulators, the male- or female-derived fibroblasts were reprogrammed into LLCs with main LC-specific traits. Transcriptomic analysis further indicated that the correlation coefficients of global genes and transcription factors between LLCs and LCs were higher than 0.81 and 0.96, respectively. After transplantation in the testes of hypogonadal rodent models, LLCs increased serum testosterone concentration significantly. In type 2 diabetic rats model, LLCs which were transplanted in armpit, have the capability to restore the serum testosterone level and improve the hyperglycemia status. In conclusion, our approach enables skin-derived fibroblasts reprogramming into LLCs with high fidelity, providing a potential cell source for the therapeutics of male hypogonadism and metabolic-related comorbidities.

A Bayesian Modeling Approach to Examine the Role of Testosterone Administration on the Endowment Effect and Risk-Taking

Financial risk-taking and loss aversion are multifaceted phenomena that are the focus of neuroscience, psychology, and economics research. A growing number of studies highlighted the role of hormones (particularly of testosterone) on socio-economic decision-making. However, the effects of testosterone on risk-taking under framing and consumer-based choices and preferences are inconclusive. We investigated the effects of 100 mg testosterone administration on aspects of decision-making within the Prospect Theory framework which is the most used descriptive model of decision-making under risk. We assessed risk-taking under framing and the endowment effect (effect of possession) using Bayesian modeling. Forty men participated in this double-blind placebo-controlled fully-randomized cross-over experiment and performed two tasks. One was a risk-taking task with binary choices under positive and negative framing associated with different probabilities. In the second task participants had to bid money for hedonic and utilitarian items. We observed a significant increase in serum testosterone concentrations after transdermal application. Compared to placebo, testosterone administration increased risk-taking under the positive framing (very large effect size) and decreased under the negative framing (moderate to small). The sensitivity to gain was positive in each framing. Our model showed that decision-making is jointly influenced by testosterone and the trade-off between gains and losses. However, while the endowment effect was more pronounced for hedonic than for utilitarian items, the effect was independent of testosterone. The findings provide novel information on the complex modulatory role of testosterone on risk-taking within the framework of prospect theory and shed light on mechanisms of behavioral economic biases. The proposed models of effects of individual differences in testosterone on risk-taking could be used as predictive models for reference-depended behavior under positive and negative framing with low and high probabilities.

Testicular antioxidants and testosterone enhancing effects of the hydro-ethanolic extract of Rauvolfia vomitoria (Apocynacaea) in male Wistar rats

Abstract Background: Natural products such as extracts of plants have been seen as a possible alternative to conventional therapies in the treatment and management of male infertility. This study aimed at investigating the testicular antioxidant and testosterone enhancing ability of the hydro-alcoholic extract of Rauvolfia vomitoria in male rats. Methods: Twenty-four male rats were divided into four groups of 6 rats each, treated daily with either vehicle (distilled water; 5 mL/kg) or hydro-ethanolic extract of R. vomitoria (20 mg/kg, 40 mg/kg, and 100mg/kg) for 60 days, and body weights recorded once every three days. At the end of the treatment, each animal was sacrificed, and reproductive organs were dissected out and weighed. Serum from capillary blood was used for testosterone quantification, while testicular homogenates were used for the estimation of antioxidant biomarkers. Results: Treatment with R. vomitoria extract did not alter the animal’s body weight. Instead, the extract at the dose of 40 mg/kg significantly increased (P< 0.05) the weights of all reproductive organs investigated. The plant extract also increased serum testosterone concentrations significantly (P< 0.05), with the highest effect observed in the animals treated with a dose of 40 mg/kg. Testicular antioxidant markers, thiobarbituric acid substances, glutathione, and catalase were equally improved (P< 0.05) by treatment with the plant extract at the dose of 40 mg/kg. Conclusion: Hydro-ethanolic extract of R. vomitoria portrayed beneficial pharmacological properties on reproductive organs, testicular antioxidants, and testosterone concentrations in male rats. These pharmacological activities support the traditional use of the plant in the management of male fertility disorders.

Perfluoroalkyl and polyfluoroalkyl substance exposure and association with sex hormone concentrations: results from the NHANES 2015\u20132016

BackgroundThere is increasing global concern regarding the health impacts of perfluoroalkyl and polyfluoroalkyl substances (PFAS), which are emerging environmental endocrine disruptors. Results from previous epidemiological studies on the associations between PFAS exposure and sex hormone levels are inconsistent.ObjectiveWe examined the associations between serum PFAS compounds (PFDeA, PFHxS, PFNA, PFOA, PFOS) and sex hormones, including total testosterone (TT), free testosterone (FT), estradiol (E), and serum hormone binding globulin (SHBG).ResultsAfter adjusting for potential confounders, PFDeA, PFOS, and PFHxS exposures were significantly associated with increased serum testosterone concentrations in males. PFDeA, PFOA, and PFOS exposures were positively correlated with FT levels in 20–49-year-old women, while PFOS exposure was negatively associated with TT levels in 12–19-year-old girls. PFAS exposure was negatively associated with estradiol levels including: PFDeA in all females, PFHxS, PFNA, PFOS, and PFOA in 12–19-year-old girls, PFNA in women above 50 years, and PFOA in 12–19-year-old boys, while PFDeA and PFOS exposures were positively associated with estradiol levels in these boys. n-PFOS exposure was positively associated with SHBG levels in men older than 20 and in all females.ConclusionsUsing a large cohort of males and females aged from 12 to 80, we found that PFAS exposure appears to disrupt sex hormones in a sex-, age-, and compound-specific manner. Future work is warranted to clarify the causality and mechanisms involved.

High-fructose diet during puberty alters the sperm parameters, testosterone concentration, and histopathology of testes and epididymis in adult Wistar rats.

The consumption of fructose has increased in children and adolescents and is partially responsible for the high incidence of metabolic diseases. The lifestyle during postnatal development can result in altered metabolic programming, thereby impairing the reproductive system and fertility during adulthood. Therefore, the aim of this study was to evaluate the effect of a high-fructose diet in the male reproductive system of pubertal and adult rats. Male Wistar rats (30 d old) were assigned to four different groups: Fr30, which received fructose (20%) in water for 30 d and were euthanized at postnatal day (PND) 60; Re-Fr30, which received fructose (20%) for 30 d and were euthanized at PND 120; and two control groups C30 and Re-C30, which received water ad libitum and were euthanized at PND 60 and 120, respectively. Fructose induced an increase in abnormal seminiferous tubules with epithelial vacuoles, degeneration, and immature cells in the lumen. Moreover, Fr30 rats showed altered spermatogenesis and daily sperm production (DSP), as well as increased serum testosterone concentrations. After discontinuing high-fructose consumption, DSP and sperm number decreased significantly. We observed tissue remodeling in the epididymis, with a reduction in stromal and epithelial compartments that might have influenced sperm motility. Therefore, we concluded that fructose intake in peripubertal rats led to changes in the reproductive system observed both during puberty and adulthood.

Various Factors May Modulate the Effect of Exercise on Testosterone Levels in Men.

Exercise has been proposed to increase serum testosterone concentrations. The analysis of existing literature demonstrates a large degree of variability in hormonal changes during exercise. In our manuscript, we summarized and reviewed the literature, and concluded that this variability can be explained by the effect of numerous factors, such as (a) the use of different types of exercise (e.g., endurance vs. resistance); (b) training intensity and/or duration of resting periods; (c) study populations (e.g., young vs. elderly; lean vs. obese; sedentary vs. athletes); and (d) the time point when serum testosterone was measured (e.g., during or immediately after vs. several minutes or hours after the exercise). Although exercise increases plasma testosterone concentrations, this effect depends on many factors, including the aforementioned ones. Future studies should focus on clarifying the metabolic and molecular mechanisms whereby exercise may affect serum testosterone concentrations in the short and long-terms, and furthermore, how this affects downstream mechanisms.

Productive and Physiological Response of Male Rabbits to Dietary Supplementation with Thyme Essential Oil.

Simple SummaryThe present study was carried out to compare the potential effects of the levels of thyme essential oil on the productive performance and serum metabolic profile of male rabbits. Rabbits were assigned to five dietary treatments including a basal diet as a negative control, a basal diet supplemented with an antibiotic as a positive control, and a basal diet supplemented with 60, 120, or 180 mg/kg of thyme essential oil. The main results showed that the levels of thyme essential oil contributed to the improvement of productive and the physiological response compared with the negative and positive control of male rabbits.The present study aimed at assessing the efficiency of thyme essential oil (TEO) as an alternative to antibiotics for improving the productive performance and serum metabolic profile of male rabbits. A total of one hundred and fifty 70-day-old male Californian rabbits were assigned to five dietary treatments, including a basal diet as a negative control (NC), a basal diet supplemented with an antibiotic as a positive control (PC), and a basal diet supplemented with 60, 120, or 180 mg/kg of TEO. The experiment period lasted for 60 days. Supplementation of TEO levels significantly (P < 0.01) increased daily body weight gain and improved feed conversion ratio of male Californian rabbits compared to NC and PC groups. Similarly, the TEO remarkably enhanced the semen characteristics of rabbits compared to NC and PC groups. Supplementation of TEO significantly decreased aspartate transaminase, alanine transaminase, urea, and creatinine compared with NC and PC groups. Supplementation with TEO increased serum testosterone concentration compared to NC and PC treatments. Our data demonstrate that TEO levels up to 180 mg/kg can play a major role as an alternative to dietary antibiotics, in improving the productive performance, semen quality, testosterone levels, and the kidney and liver functions in California male rabbits.

Male Obesity Associated Gonadal Dysfunction and the Role of Bariatric Surgery.

Obesity is an ever growing pandemic and a prevalent problem among men of reproductive age that can both cause and exacerbate male-factor infertility by means of endocrine abnormalities, associated comorbidities, and direct effects on the precision and throughput of spermatogenesis. Robust epidemiologic, clinical, genetic, epigenetic, and preclinical data support these findings. Clinical studies on the impact of medically induced weight loss on serum testosterone concentrations and spermatogenesis is promising but may show differential and unsustainable results. In contrast, literature has demonstrated that weight loss after bariatric surgery is correlated with an increase in serum testosterone concentrations that is superior than that obtained with only lifestyle modifications, supporting a further metabolic benefit from surgery that may be specific to the male reproductive system. The data on sperm and semen parameters is controversial to date. Emerging evidence in the burgeoning field of genetics and epigenetics has demonstrated that paternal obesity can affect offspring metabolic and reproductive phenotypes by means of epigenetic reprogramming of spermatogonial stem cells. Understanding the impact of this reprogramming is critical to a comprehensive view of the impact of obesity on subsequent generations. Furthermore, conveying the potential impact of these lifestyle changes on future progeny can serve as a powerful tool for obese men to modify their behavior. Healthcare professionals treating male infertility and obesity need to adapt their practice to assimilate these new findings to better counsel men about the importance of paternal preconception health and the impact of novel non-medical therapeutic interventions. Herein, we summarize the pathophysiology of obesity on the male reproductive system and emerging evidence regarding the potential role of bariatric surgery as treatment of male obesity-associated gonadal dysfunction.

Oxidative Stress and Endoplasmic Reticulum Stress Are Involved in the Protective Effect of Alpha Lipoic Acid Against Heat Damage in Chicken Testes.

Simple SummaryIn male animals, heat stress causes injury to the testes, resulting in an increase in the number of deformed sperm, a reduction in testosterone production, and consequently, reduced reproductive performance. As an important antioxidant, alpha lipoic acid (ALA) has been reported to have a protective effect against testicular injury caused by various pathological factors. However, few studies have focused on the role of ALA in heat-induced testicular lesions. In this study, the effects of ALA on histopathological parameters, the activity of key antioxidant enzymes involved in oxidative stress, biomarkers of endoplasmic reticulum stress signaling in the testicular tissue, and testosterone levels in serum were evaluated in heat-stressed chickens. The results showed that ALA significantly alleviated heat stress-induced adverse effects by affecting the activities of antioxidant enzymes, the expression of endoplasmic reticulum stress-related apoptotic modulators, and the protein levels of steroidogenic genes in the testes of chickens exposed to heat stress. These results suggest that in chickens, ALA may be beneficial for ameliorating decreased reproductive performance caused by heat stress and this study provides the basis for the design of novel therapies for heat-induced testicular damage.Heat stress (HS) causes testicular injury, resulting in decreased fertility. Alpha-lipoic acid (ALA) is a well-known antioxidant. The aim of this study was to investigate the protective effects of ALA on HS-induced testicular damage in chickens. Histological changes; biomarkers of oxidative stress, including glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA); markers of endoplasmic reticulum (ER) stress, including glucose-regulated protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP); apoptosis-related modulators, including Bax, Bcl-2, and caspase 3, in testicular tissue and serum testosterone levels were evaluated in chickens under heat stress. Heat stress induces spermatogenic cell abnormalities in chicken testes. Compared to the HS group, the histomorphological abnormalities in testicular tissue were visibly ameliorated, with significant increases in the enzyme activities of GPx, SOD, and CAT, increased serum testosterone concentration, and decreased MDA levels in the ALA + HS group. Consistent with these results, compared with the HS group, the protein levels of GRP78, CHOP, caspase 3, and Bax were significantly decreased, whereas Bcl-2, StAR, and 3β-HSD protein levels were increased in the ALA + HS group. Collectively, these findings suggest that ALA significantly ameliorates the heat-induced histomorphological abnormalities in the testes and decreased testosterone production by potentiating the activities of anti-oxidative enzymes (GPx, SOD, and CAT), inhibiting ER stress-related apoptotic pathways (Bax, Bcl-2, and caspase 3), and increasing steroidogenic gene (StAR and 3β-HSD) expression in chickens.

Effects of &lt;i&gt;Anthocleista Djalonensis&lt;/i&gt; (Chev.) methanol root bark extract on some fertility parameters in male rats

Background: Anthocleista djalonensis is a West African plant with several ethnomedicinal uses.Objectives: This study evaluated the effect of Anthocleista djalonensis methanol root bark extract on fertility parameters in male rats.Material and Methods: The rats were randomly allotted to four groups (n=5). Group A (control) received distilled water (10 ml/kg), groups B, C, D received oral doses of 100, 200 and 400 mg/kg/day of the extract respectively for 28 days. The mean body, testicular, and epididymal weights; sperm indices; and serum testosterone level were assessed.Results: There were no significant changes on the body weights of the treated rats but their testicular and epididymal weights increased significantly (P˂0.05) at the dose of 400 mg/kg in comparison with the control group. Sperm indices such as sperm count, motility, morphology and viability increased significantly (P˂0.05) at the doses of 200 and 400 mg/kg/day when compared to the control. There was also a significant (P˂0.05) increase in serum testosterone concentration at the dose of 400 mg/kg/day of the extract.Conclusion: The results suggest that the methanol root bark extract of A. djalonensis improves fertility parameters in male rats thereby justifying its use in ethnomedicine.Keywords: Sperm count, testosterone level, spermatogenesis, oxidative stress

The Effect of Zinc, Selenium, and Their Combined Supplementation on Androgen Receptor Protein Expression in the Prostate Lobes and Serum Steroid Hormone Concentrations of Wistar Rats.

Background: Zinc (Zn) and selenium (Se) play a well-documented role in cancer prevention (e.g., for prostate cancer), and their combined supplementation is often given as a recommended prophylactic agent. The aim of the study was to determine the influence of Zn and/or Se supplementation on the androgen receptor (AR) in the prostate lobes and the serum selected hormone concentrations; a hitherto unresearched topic. Methods: Male rats (n = 84) were administered with Zn and/or Se intragastrically for up to 90 days. The effects of administration on the tested parameters were checked after 30 and 90 days of administration and additionally, 90 days after the end of 90 day administration. Results: Zn alone leads to an increase in serum testosterone concentrations, while the protein expression of AR in both parts of the prostate increases. Combined administration of Zn and Se eliminates the effect of Zn, which may suggest that these two elements act antagonistically. Se supplementation alone results in the same level of AR protein expression in administration and 90 days after administration periods. Conclusion: This paper presents the first report of the influence of Zn and/or Se supplementation on the protein expression of AR in the prostate. Our findings seem to indicate that simultaneous supplementation of both elements may be ineffective.

Acute effects of very low-volume high-intensity interval training on muscular fatigue and serum testosterone level vary according to age and training status.

To compare the acute physiological responses of three different very low-volume cycling sessions (6 × 5s, 3 × 30s, and 3 × 60s) and their dependence on age and training status. Subjects were untrained young men (mean ± SD; age 22.3 ± 4.6years, VO2peak 42.4 ± 5.5ml/kg/min, n = 10), older untrained men (69.9 ± 6.3years, 26.5 ± 7.6ml/kg/min, n = 11), and endurance-trained cyclists (26.4 ± 9.4years, 55.4 ± 6.6ml/kg/min, n = 10). Maximal voluntary contraction (MVC) and electrically stimulated knee extension torque, and low-frequency fatigue, as ratio of stimulation torques at 20-100Hz (P20/100), were measured only 24h after exercise. Serum testosterone (Te) and blood lactate concentrations were measured only 1h after exercise. All protocols increased the blood lactate concentration and decreased MVC and P20/100 in young men, but especially young untrained men. In old untrained men, 6 × 5s decreased P20/100 but not MVC. Te increased after 3 × 30s and 3 × 60s in young untrained men and after 3 × 60s in older untrained men. The increase in Te correlated with responses of blood lactate concentration, MVC, and P20/100 only in old untrained men. As little as 6 × 5s all-out cycling induced fatigue in young and old untrained and endurance-trained cyclists. Slightly higher-volume sessions with longer intervals, however, suppressed contractile function more markedly and also transiently increased serum testosterone concentration in untrained men.

Smad ubiquitylation regulatory factor 1 promotes LIM-homeobox gene 9 degradation and represses testosterone production in Leydig cells.

Testosterone is essential for spermatogenesis and the maintenance of secondary sexual characteristics in males. An important transcription factor, LIM-homeobox gene 9 (Lhx9) is indispensable for testis development and testosterone production; however, post-translational modifications of Lhx9 are largely unknown. Here, for the first time to our knowledge, we demonstrate that the level of Lhx9 protein increases in human chorionic gonadotropin-exposed Leydig cells and can be polyubiquitylated. We found that Smad ubiquitylation regulatory factor 1 (Smurf1), an E3 ubiquitin ligase, targets Lhx9 for ubiquitin-mediated proteasome degradation, thereby negatively modulating its function. Increasing Smurf1 decreases the level of Lhx9 and inhibits the Lhx9 transactivation capacity of steroidogenic factor 1 [nuclear receptor subfamily 5, group A, member 1 (NR5A1)]. In contrast, the depletion of Smurf1 leads to increased expression of Lhx9 protein and enhances testosterone biosynthesis-related gene transcripts [NR5A1, steroidogenic acute regulatory protein, CYP17A1, hydroxy-δ-5-steroid dehydrogenase, hydroxy-δ-5-steroid dehydrogenase isomerase 6, and hydroxysteroid (17-β) dehydrogenase 3] and testosterone production in Leydig cells. Furthermore, we found that Smurf1 knockout mice exhibit higher levels of Lhx9 protein and steroidogenesis, which leads to increased serum testosterone concentration. These findings reveal that Smurf1 promotes Lhx9 ubiquitylation and is involved in testosterone production in Leydig cells directly. Our results provide new insights into the molecular events that play a role in the homeostasis of testosterone levels and may provide a new target for testosterone regulation.-Hu, F., Zhu, Q., Sun, B., Cui, C., Li, C., Zhang, L. Smad ubiquitylation regulatory factor 1 promotes LIM-homeobox gene 9 degradation and represses testosterone production in Leydig cells.

Effects of HRV-Guided vs. Predetermined Block Training on Performance, HRV and Serum Hormones.

The aim of this study was to compare heart rate variability -guided (HRVG) and predetermined (PD) block periodization of high intensity aerobic training (HIT). Endurance performance, neuromuscular performance, heart rate variability (HRV) and serum hormone concentrations were measured before, in the middle and after the 8-week training period in 24 endurance trained males. Both groups improved significantly maximal treadmill velocity (Vmax) (p<0.001) and 3000 m running performance (HRVG; p<0.001 and PD; p=0.001). The relative changes in Vmax and countermovement jump were significantly greater in HRVG (p<0.05). Nocturnal heart rate decreased in both groups (p<0.01), but HRV (RMSSD, LF and TP) increased significantly only in HRVG (p<0.05). The significant increase in serum testosterone concentration was observed from mid to post in HRVG (p<0.05). Significant correlations were found between individual Vmax changes and absolute serum testosterone levels. Individual baseline level of HF correlated significantly with Vmax changes in PD. Block periodization of HIT seems to be an effective way to improve endurance and running performance in already endurance trained males. Based on training induced increases in endurance and neuromuscular performance combined with significant changes in HRV and serum testosterone levels observed in HRVG, individually HRV -guided block training may be more optimal compared to predetermined training.

Body and testicular development and serum testosterone concentrations in Brahman males

The present study had the objective of evaluating the physical and testicular development, and the serum testosterone concentration of 8 to 18 months old male Brahman cattle on grazing weight gaining performance tests. Bovine cattle (n=40), aged 259.76 ± 26.15 days and weighing 239.71 ± 33,94kg had the following characteristics evaluated every 56 days, corresponding to 8, 10, 12, 14, 16, and 18 months of age (six different data collections): body weight (BW), scrotal circumference (SC), girth (G), height at the withers (WH), body length (BL), body mass index (BMI), right and left testicular length (RTL and LTL, respectively), right and left testicular height (RTH and LTH, respectively), average daily weight gain (ADG), testicular volume (TV), and serum testosterone (ST).Analysis of variance and Tukey's test at 5% probability were used. Correlations between variables were assessed using Pearson's method at 5% confidence. There was significant difference (P &lt; 0.05) from 12 months of age onwards for ADG and ST. There were differences (P &lt; 0.05) for: BW, SC, G, WH, BL, BMI, RTL, LTL, RTH,and TV from 14 months of age. There was a positive correlation between: ST x G (r=0.38; P &lt; 0.01); ST x WH (r=0.38; P &lt; 0.01); ST xRTH (r=0.23; P &lt; 0.05); ST x LTH (r=0.21; P &lt; 0.01); ST x TV (r=0.22; P &lt; 0.008); TV x weight (r=0.70; P &lt; 0.01); TV x SC (r=0.90; P &lt; 0.01); and TV x BMI (r=0.93; P &lt; 0.01). A rapid increase in serum testosterone concentration occurred between 12 and 14 months of age, followed by rapid body and testicular growth. An elevation in testosterone levels is an indirect indicator that an acceleration inphysical and testicular growth is approaching. It is recommended to calculate both BMI and TV to follow cattle growth due to the high correlation between these variables.

Body and testicular development and serum testosterone concentrations in Brahman males

The present study had the objective of evaluating the physical and testicular development, and the serum testosterone concentration of 8 to 18 months old male Brahman cattle on grazing weight gaining performance tests. Bovine cattle (n=40), aged 259.76 ± 26.15 days and weighing 239.71 ± 33,94kg had the following characteristics evaluated every 56 days, corresponding to 8, 10, 12, 14, 16, and 18 months of age (six different data collections): body weight (BW), scrotal circumference (SC), girth (G), height at the withers (WH), body length (BL), body mass index (BMI), right and left testicular length (RTL and LTL, respectively), right and left testicular height (RTH and LTH, respectively), average daily weight gain (ADG), testicular volume (TV), and serum testosterone (ST).Analysis of variance and Tukey's test at 5% probability were used. Correlations between variables were assessed using Pearson's method at 5% confidence. There was significant difference (P &lt; 0.05) from 12 months of age onwards for ADG and ST. There were differences (P &lt; 0.05) for: BW, SC, G, WH, BL, BMI, RTL, LTL, RTH,and TV from 14 months of age. There was a positive correlation between: ST x G (r=0.38; P &lt; 0.01); ST x WH (r=0.38; P &lt; 0.01); ST xRTH (r=0.23; P &lt; 0.05); ST x LTH (r=0.21; P &lt; 0.01); ST x TV (r=0.22; P &lt; 0.008); TV x weight (r=0.70; P &lt; 0.01); TV x SC (r=0.90; P &lt; 0.01); and TV x BMI (r=0.93; P &lt; 0.01). A rapid increase in serum testosterone concentration occurred between 12 and 14 months of age, followed by rapid body and testicular growth. An elevation in testosterone levels is an indirect indicator that an acceleration inphysical and testicular growth is approaching. It is recommended to calculate both BMI and TV to follow cattle growth due to the high correlation between these variables.

Serum and follicular fluid testosterone concentrations do not correlate, questioning the impact of androgen supplementation on the follicular endocrine milieu

Basic research into a possible link between serum and follicular fluid androgen concentrations to detemine whether androgen supplementation in low responders affects follicular endocrine milieu is still lacking. Ninety-seven women (aged 28–43 years) undergoing one natural IVF cycle without any hormone stimulation were analysed. Serum and follicular fluid were collected at the time of follicle aspiration, and the concentrations of LH, total testosterone, oestradiol, dehydroepiandrosterone and anti-Mullerian hormone (AMH) were determined. Serum LH (P = 0.003) and AMH (P = 0.026) concentrations, and follicular fluid AMH (P = 0.015) decreased with increasing age. Within follicular fluid, total testosterone was correlated with oestradiol (P < 0.001) and AMH (P = 0.010); LH correlated with AMH (P = 0.005). Correlation analysis of serum and follicular fluid hormone concentrations revealed that LH, oestradiol and AMH correlated (P < 0.001), whereas testosterone did not. Testosterone serum concentrations did not correlate with other follicular fluid hormones, such as dehydroepiandrosterone, oestradiol and AMH, whereas serum LH correlated with follicular flulid AMH (P < 0.008). Follicular fluid hormone concentrations seem to be independent from serum testosterone. Therefore, it is questionable whether an increase in serum testosterone concentration by androgen supplementation could improve the follicular endocrine milieu.

Chronic stress effects and their reversibility on the Fallopian tubes and uterus in rats.

The durational effects of chronic stress on the Fallopian tubes and uterus were studied by exposing rats to stressors in the form of restraint (1h) and forced swimming (15min) daily for 4, 8 or 12 weeks. One group of stressed rats from each time period was then maintained without exposure to stressors for a further 4 weeks to assess their ability to recover from stress. All time periods of stress exposure resulted in decreased weight of the body and Fallopian tubes; however, the relative weight of the uterus and serum concentrations of oestradiol and insulin increased significantly. The antioxidant potential was decreased with increased malondialdehyde concentrations in the Fallopian tubes following all durations of exposure and after 4 and 8 weeks of stress exposure in the uterus. Interestingly, rats stressed for 12 weeks showed an increase in serum testosterone concentration and antioxidant enzyme activities with a decrease in malondialdehyde concentration in the uterus. The antioxidant enzyme activities and malondialdehyde concentration in the Fallopian tubes of all recovery group rats were similar to stressed rats. However, in the uterus these parameters were similar to controls in recovery group rats after 4 weeks or 8 weeks of exposure, but after 12 weeks of stress exposure these parameters did not return to control levels following the recovery period. These results reveal, for the first time, that chronic stress elicits an irreversible decrease in antioxidant defence in the Fallopian tubes irrespective of exposure duration, whereas the uterus develops reversible oxidative stress under short-term exposure but increased antioxidant potential with endometrial proliferation following long-term exposure.