Influence Of Testosterone Research Articles

Evaluation of androgen receptor markers in erectile dysfunction.

Steroid hormones, such as testosterone, play a crucial role in modulating the development of male internal and external genitalia as well as secondary sex characteristics by binding to the androgen receptor. Once bound, androgen receptor operates as an inducible transcription factor, interacting with a multitude of co-regulators to initiate various downstream signaling pathways. The androgen saturation hypothesis posits that beyond a specific threshold, androgen receptor binding and functionality remain unaltered despite an increase in serum testosterone levels. The objective of this study was to explore the expression of these proteins in penile tissue samples from men with severe erectile dysfunction to enhance our understanding of the influence of serum testosterone on androgen receptor function. Patients undergoing surgical management for high-grade ED at our institution were invited to participate in the study. During inflatable penile prosthesis surgery, corpus cavernosum biopsy was obtained. Protein was extracted from each sample for western blot analysis which was probed with androgen receptor, heme oxygenase, inducible nitric oxide synthase, and phosphodiesterase type 5 antibodies with GAPDH for protein normalization. 12 men agreed to participate in this study. Serum testosterone levels were obtained from all participants on the morning of their surgery. The median testosterone level was 300.15 ng/dL. Our findings revealed a decrease in androgen receptor and inducible nitric oxide synthase expression at serum testosterone levels below 300 ng/dL (p = 0.022, 0.03). Similarly, hemeoxygenase and phosphodiesterase type 5 expression levels were significantly lower at serum T concentrations below 200 ng/dL (p = 0.017, 0.014). These data showed a significant decrease in the expression of proteins downstream of the androgen receptor at lower serum T levels. This suggests a potential correlation between serum T concentration and androgen receptor signaling and supports a potential saturation value between 200 and 300 ng/dL.

Arrhythmogenic substrate elimination for safe testosterone therapy in symptomatic Brugada syndrome patients.

Brugada Syndrome (BrS) is a cardiogenetic disease known for its association with sudden cardiac death (SCD) in individuals with structurally normal hearts. The prevalence of BrS is higher in males, who also face a greater risk of SCD. Its higher prevalence and worse outcome in male subjects may be due to testosterone effects on ion channels expression and function. The influence of testosterone on cardiac action potentials, both genomically and non-genomically, underscores its potential role in unmasking the syndrome and triggering life-threatening arrhythmias. Notably, testosterone replacement therapy (TRT), used for hypogonadism and gender reassignment, has been linked to BrS unmasking. The role of epicardial ablation in symptomatic BrS patients where hormonal therapy cannot be discontinued is unknown. In this study we describe the first two cases of substrate mapping and ablation in BrS patients experiencing arrhythmic events while on TRT. In both cases, high-density epicardial mapping revealed abnormal areas of prolonged and fragmented electrograms in the right ventricular (RV) outflow tract and anterior wall. These abnormalities were completely abolished by radiofrequency ablation (RFA). After ablation, both patients showed a persistent normalization of the ECG and were free from ventricular arrhythmias at follow-up, despite ongoing TRT. RFA can be considered as a therapeutic option in symptomatic BrS patients with a high-risk profile who cannot discontinue TRT, being essential for restoring their normal physiology or preserving their sexual identity. As testosterone use is increasing, further studies are warranted to define a standardized diagnostic and therapeutic strategy in this specific subset of BrS patients.

Influence of Testosterone in Neglected Tropical Diseases: Clinical Aspects in Leprosy and In Vitro Experiments in Leishmaniasis.

Neglected tropical diseases encompass a group of chronic and debilitating infectious diseases that primarily affect marginalized populations. Among these diseases, leprosy and leishmaniasis are endemic in numerous countries and can result in severe and disfiguring manifestations. Although there have been reports indicating a higher incidence of leprosy and leishmaniasis in males, the underlying factors contributing to this observation remain unclear. Therefore, the objective of this study was to examine both clinical and experimental evidence regarding the role of testosterone in leprosy and leishmaniasis. A prospective clinical study was conducted to compare the clinical forms of leprosy and assess circulating testosterone levels. Additionally, the impact of testosterone on Leishmania amazonensis-infected macrophages was evaluated in vitro. The findings demonstrated that serum testosterone levels were higher in women with leprosy than in the control group, irrespective of the multi- or pauci-bacillary form of the disease. However, no differences in testosterone levels were observed in men when comparing leprosy patients and controls. Interestingly, increasing doses of testosterone in macrophages infected with L. amazonensis resulted in a higher proportion of infected cells, decreased CD40 expression on the cell surface, elevated expression of SOCS1, and decreased expression of IRF5. These findings provide biological evidence to support the influence of testosterone on intracellular infections, though the interpretation of clinical evidence remains limited.

The Beneficial Influence of Testosterone in Hepatic Ischemia/Reperfusion Injury and Its Possible Mechanisms

The Beneficial Influence of Testosterone in Hepatic Ischemia/Reperfusion Injury and Its Possible Mechanisms

Altered cardiac repolarization associated with cellular electrophysiological remodeling following chronic testosterone undecanoate administration in a canine model

Abstract Funding Acknowledgements Type of funding sources: None. Background The influence of testosterone on ventricular ion channels is widely investigated. Despite the legally stipulated availability of different androgen anabolic steroids (AAS), these agents are very popular among young adults, however, the direct effects of supra-physiological testosterone level are still unclear. Supposedly, the chronic use of AASs may result in structural and functional remodeling of the heart. Purpose The aim of our study was to investigate the potential electrophysiological effects of chronic administration of testosterone-undecanoate in a canine model in in vivo and in vitro studies. Methods Eight male beagle dogs were randomized into control (’Cont’) and treated (’Tr’) groups (n = 4; n = 4). The latter group received 15 mg/kg of long-lasting testosterone-undecanoate intramuscular injections weekly for 3 months. Blood samples were taken for monitoring testosterone levels. To investigate the altered repolarization in conscious dogs electrocardiography studies were performed. Ventricular myocytes were enzymatically dissociated via retrograde perfusion. The transmembrane ionic currents were recorded using the whole-cell configuration of the patch-clamp technique and the action potential duration (APD) was measured by the perforated patch-clamp technique. Results Testosterone level was significantly higher in the ‘Tr’ group compared to the ‘Cont’ group (47.02 nm/L vs. 15.23 nm/L; p=0.0002). The chronic treatment did not affect the heart rate between the examined groups (93.7±23.5 vs.108.8±21.4 beats/min), however, it resulted in significantly shortened QT (226±49 vs. 244.9±26.6 ms; p<0.05) and QTc (26.06±2.5 vs. 29.6±3.01 ms, p<0.05) intervals. ECG recordings also presented prolonged PQ (112.1±15.5 vs. 61.65±12.7ms; p<0.05), QRS (72.37±15.4 vs. 61.65±12.7 ms; p<0.05), and Tp-Te (32.95±7.45 vs. 53.46±16.6 ms; p<0.05) intervals in the ‘Tr’ group. Additionally, the APD of isolated left ventricular myocytes significantly shortened in the ‘Tr’ group compared to the ‘Con’ group (235.2±26.7 vs. 283.6±28.5 ms; p<0.05). Patch-clamp experiments revealed increased magnitude of transient outward potassium current (Ito), the inward rectifier potassium current (Ik1), and the slowed delayed rectifier potassium current (Iks) in the ‘Tr’ group. Conclusion The repolarization of the canine ventricular myocardium was significantly modified by constantly high level of testosterone. Many beneficial effects are attributed to physiological testosterone levels; however, the supra-physiological testosterone level may lead to potentially harmful alternations in the cardiac repolarization that may promote arrhythmogenesis, especially in the presence of various heart diseases. Presumably, the constantly high testosterone level induced electrophysiological changes may contribute to the development of life-threatening arrhythmias under certain circumstances.

The cardiovascular subtleties of testosterone on gender-affirming hormone therapy.

The growing number of people who identify themselves as transgender has gained increased attention in recent years and will certainly impact personalized clinical practices and healthcare worldwide. Transgender and gender-nonconforming individuals frequently undergo gender-affirming hormone therapy (GAHT), i.e., they use sex hormones to align their gender identity with their biological characteristics. Testosterone is the main compound used in GAHT by transmasculine people, leading to the development of male secondary sexual characteristics in these individuals. However, sex hormones, testosterone included, also influence hemodynamic homeostasis, blood pressure, and cardiovascular performance by direct effects in the heart and blood vessels, and by modulating several mechanisms that control cardiovascular function. In pathological conditions and when used in supraphysiological concentrations, testosterone is associated with harmful cardiovascular effects, requiring close attention in its clinical use. The present review summarizes current knowledge on the cardiovascular impact of testosterone in biological females, focusing on aspects of testosterone use by transmasculine people (clinical goals, pharmaceutical formulations, and impact on the cardiovascular system). Potential mechanisms whereby testosterone may increase cardiovascular risk in these individuals are discussed, and the influence of testosterone on the main mechanisms that control blood pressure and that potentially lead to hypertension development and target-organ damage are also reviewed. In addition, current experimental models, which are key to reveal testosterone mechanistic aspects and potential markers of cardiovascular injury, are reviewed. Finally, research limitations and the lack of data on cardiovascular health of transmasculine individuals are considered, and future directions for more appropriate clinical practices are highlighted.

Testosterone administration enhances the expectation and perception of painful and non-painful somatosensory stimuli

The influence of testosterone on pain perception remains inconsistent in the literature. This randomized, placebo-controlled, double-blind, crossover study investigated the effect of testosterone administration on perception and expectation of electrocutaneous stimulus. Thirty healthy male participants received a single dose of testosterone in one session and a placebo in the other session. For each session, they completed a pain-rating task in which a predictability cue was inserted before a painful or non-painful electocutaneous stimulus delivery, while neural activity was simultaneously recorded by a 64-channel electroencephalographic (EEG) system. Expected and perceived pain ratings, as well as event-related potentials (ERPs) to electocutaneous stimuli and prestimulus EEG oscillatory activities while expecting upcoming electocutaneous stimuli were comprehensively compared between testosterone and placebo sessions. Compared with the placebo session, participants in the testosterone session reported greater pain rating and exhibited greater amplitude of N1 component on ERPs when perceiving both painful and non-painful electrocutaneous stimuli. Mediation analysis revealed that testosterone enhanced the pain-intensity ratings via the N1 response to the electrocutaneous stimulus. Upon viewing the predictability cues after testosterone administration, expected pain intensity increased and spontaneous low-frequency α-oscillation power in the frontal region decreased. These results provide evidence that testosterone enhanced perception and expectation of somatosensory events, and that this was a general effect rather than pain-specific. A plausible explanation for these findings is that testosterone acts to increase vigilance and sustained attention levels, as evidenced by the decreased α-oscillation power. Thus, our findings support a causal role for testosterone in heightening the biological salience of incoming somatosensory information.

Variasi Pola Trauma pada Kasus Kematian Akibat Tindak Kekerasan Berdasarkan Data Autopsi di Instalasi Forensik RSUD Dr. Doris Sylvanus Tahun 2016 – 2020

Based on BPS data, the crime rate in Indonesia from 2015 – 2019 tends to decrease, But Central Kalimantan province, which is one of the provinces with the lowest population, has a high crime rate that causes death, which is 12th nationally. The aim of this research is to describe the age, gender, any type of trauma, and the location of the most common injuries on the bodies that were carried out for forensic autopsies at RSUD dr. Doris Sylvanus in 2016 – 2020. This research was a descriptive observational study with approach cross sectional (cross-sectional). From a population of 150 corpse data, 68 corpse data were obtained that met the inclusion criteria. The majority of the victims were male 53 data (81.54%). The majority of victims are adults with 66 (97.06%) bodies. Sharp trauma was the most common with 33 (48.53%) bodies followed by blunt trauma as many as 29 (42.65%) bodies. The head is the most traumatized body part, namely 27 (39.71%) bodies. Most of the sharp and blunt traumas are because the tools used are easy to get and close to everyday life. Men are involved in many murder cases because the men themselves are often involved in violence due to the influence of the hormone testosterone. Adults are mostly involved with violence because at that age they are filled with various problems such as emotional tension, increased responsibility, and so on.

The influence of testosterone on the risk of cardiovascular events after percutaneous coronary intervention.

Between 2015 and 2018, 580 men undergoing PCI at a tertiary referral hospital were divided into low (<3.25 ng/mL) and normal (≥3.25 ng/mL) testosterone groups. Major adverse cardiovascular event (MACE) was defined as the composite outcome of CV death, myocardial infarction, and target lesion revascularization/target vessel revascularization (TLR/TVR) during up to 48 months follow-up after PCI. There were 111 and 469 patients in the low and normal testosterone groups, respectively, with the overall MACE rate of the former being higher than the latter (26.13% vs. 13.01%, p = 0.0006). Moreover, the overall TLR/TVR (20.72% vs. 11.73%, p = 0.0125) and myocardial infarction (3.6% vs. 0.85%, p = 0.0255) rates were significantly higher in those with low serum testosterone who also had a shorter average event-free survival analysis of MACE (25.22 ± 0.88 months) than those with normal testosterone levels (35.09 ± 0.47 months, log-rank p = 0.0004). Multiple logistic regression demonstrated an association between low serum testosterone (<3.25 ng/mL) and a higher MACE rate [odds ratio: 2.06, 95% confidence interval (CI) 1.21-3.51, p = 0.0081]. After adjusting for variables in a Cox regression model, hazard ratios (HRs) for MACE (HR: 1.88, 95% CI: 1.20-2.95, p = 0.0058) and TLR/TVR (HR: 1.73, 95% CI: 1.06-2.83, p = 0.0290) rates were higher in the low testosterone group than those in the normal testosterone group. Low serum testosterone concentrations were associated with a higher risk of MACE and TLR/TVR after PCI than those with normal testosterone levels.

The effect of testosterone on Сa&lt;sup&gt;2+&lt;/sup&gt; release stimulated by somatotropin and theophylline from intracellular stores of &lt;i&gt;Sus Scrofa Domesticus&lt;/i&gt; oocytes

Purpose. Studying the influence of testosterone on stimulated by somatotropin and theophylline liberation of Ca2+ from intracellular depot of oocytes of pigs.Materials and methods. The material for the studies was oocytes secreted from antral follicles (with a diameter of 3-6 mm) of the ovarian Sus Scrofa domesticus. Oocyte complexes were aspirated from the ovaries at the stage of follicular growth, without signs of visible pathology. The dedicated oocytes were incubated in the modified incubation environment Dulbekko without CaCl2, containing 36 mg/l of Piruvat NA and 1 g/l glucose. Caicium in the intracellular depot of oocytes of pigs was measured with the help of a chlortetracycline (CTC) fluorescent probe. Oocytes were loaded with a probe for 5 minutes at 370C in an environment containing 40 microns of CTC. Then the cells were washed three times in an incubation environment and transferred to a special quartz glass with cells of 0.05 ml. Dependent on Ca2+ fluorescence of the CTC was recorded in oocytes in the environment of Dulbekko. The intensity of the fluorescence of the CTC probe was measured on a fluorimetric installation consisting of a fluorescent microscope, equipped with the necessary light filters and a photometric nozzle of the FMEL-1A. The CTC-Ca2+complex-the membrane excited 380-400 nm light, fluorescence was recorded in the area of 530 nm. The intensity of fluorescence was measured in the conc. units. The duration of ultraviolet radiation on oocytes during measurements did not exceed 5 seconds. In all experiments, an EGT was added to the incubation environment at a concentration of 0.5 mm.Results. It was shown that in the absence of testosterone in oocytes, the addition of somatotropin (bST) or theophylline stimulated the release of Ca2+ from intracellular depot, while their joint action did not lead to an additional exit of Ca2+ from intracellular depot. Inhibition of proteinkinase and did not affect the liberation of Ca2+, stimulated separately by bST or Theophylline, as well as their joint action. Against the background of the use of testosterone, the addition of bST or theophylline separately did not lead to the release of Ca2+ from intracellular depot. With the joint action of bST and Theophylline in the presence of testosterone, the liberation of Ca2+ from intracellular depot was noted, and the value of this indicator was higher than with the joint action of bST and Theophylline in the absence of testosterone. In stimulated by the joint action of bST and theophylline, the release of Ca2+ from the intracellular depot of oocytes in the presence of testosterone is participated in proteinquinase A and microfilaments, since when exposed to proteinquine A and polymerization of cytochalazine microfilaments release of Ca2+ from intracellular depots was not recorded.

A comprehensive review on the role of testosterone on the neurobehavioral systems implicated in the reinforcement sensitivity theory of personality

ObjectivesThe Reinforcement Sensitivity Theory (RST) is a neuropsychological theory of personality emphasizing approach and avoidance as the two core behavioral aspects. Approach is represented by the behavioral approach system (BAS). Avoidance is represented by the behavioral inhibition system (BIS) and the fight-flight-freeze system (FFFS). Although the influence of testosterone on human behavior has been demonstrated, few studies have investigated the relation between testosterone and the RST. The aim of this narrative review was to decipher the possible role of testosterone on the biological systems involved in the RST in humans. MethodsGoogle scholar, PubMed, PsycARTICLES, PsycINFO, Scopus and Cochrane library databases were interrogated using keywords such as testosterone, BIS, BAS, FFFS, personality, reinforcement sensitivity theory. ResultsSeven original articles, published between 2009 and 2022, assessing the relation between testosterone and the systems implicated in the RST, were included. The results of these studies suggested the presence of a possible positive relation between testosterone and the BAS. However, the impact of testosterone on the BIS and/or FFFS seems to be less clear. DiscussionThe consistency in the results supporting the presence of a positive relation between testosterone and the BAS might lead to the consideration of testosterone as a potential correlate in the clinical assessment of several psychopathologies. The inconsistency in the conclusions regarding the impact of testosterone on the BIS and/or the FFFS might be attributed to the different questionnaires used as measurement tools. Additional research remains needed.

The causal effect of testosterone on men's competitive behavior is moderated by basal cortisol and cues to an opponent's status: Evidence for a context-dependent dual-hormone hypothesis.

Testosterone has been theorized to direct status-seeking behaviors, including competitive behavior. However, most human studies to date have adopted correlational designs, and findings across studies are inconsistent. This experiment (n = 115) pharmacologically manipulated men's testosterone levels prior to a mixed-gender math competition and examined basal cortisol (a hormone implicated in stress and social avoidance) and context cues related to an opponent's perceived status (an opponent's gender or a win/loss in a prior competition) as factors that may moderate testosterone's impact on competitive behavior. We test and find support for the hypothesis that testosterone given to low-cortisol men evokes status-seeking behavior, whereas testosterone given to high-cortisol men evokes status-loss avoidance. In the initial rounds of competition, testosterone's influence on competitive decisions depended on basal cortisol and opponent gender. After providing opponent-specific win-lose feedback, testosterone's influence on decisions to reenter competitions depended on basal cortisol and this objective cue to status, not gender. Compared to placebo, men given exogenous testosterone who were low in basal cortisol showed an increased tendency to compete against male and high-status opponents relative to female and low-status opponents (status-seeking). Men given exogenous testosterone who were high in basal cortisol showed the opposite pattern-an increased tendency to compete against female and low-status opponents relative to male and high-status opponents (status-loss avoidance). These results provide support for a context-dependent dual-hormone hypothesis: Testosterone flexibly directs men's competitive behavior contingent on basal cortisol levels and cues that signal an opponent's status. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Testosterone Influence on Microtubule-Associated Proteins and Spine Density in Hippocampus: Implications on Learning and Memory

The thorny protrusions or spines increase the neuronal surface area, facilitate synaptic interconnections among neurons, and play an essential role in the hippocampus. Increasing evidence suggests that testosterone, the gonadal hormone, plays an important role in neurogenesis and synaptic plasticity. The role of testosterone on microtubule-associated proteins on dendritic neurite stability in the hippocampus and its impact on learning disability is not elucidated. Adult male Wistar albino rats were randomly selected for the control, castrated, castrated + testosterone, and control + testosterone groups. Bilateral orchidectomy was done, and the testosterone propionate was administered during the entire trial period, i.e., 14 days. The learning assessments were done using working/reference memory versions of the 8-arm radial maze and hippocampal tissues processed for histological and protein expressions. There were reduced expressions of microtubule-associated protein 2 (MAP2), postsynaptic density protein 95 (PSD95), and androgen receptor (AR) and increased expression of pTau in the castrated group. Conversely, the expression of MAP2, PSD95, and AR was increased, and the pTau expression was reduced in the hippocampus of the castrated rat administrated with testosterone. Androgen-depleted rats showed impaired synaptic plasticity in the hippocampus associated with contracted microtubule dynamics. Along with learning disability, there was an increased number of reference memory errors and working memory errors in castrated rats. Observations suggest that androgen regulates expression of neural tissue-specific MAPs and plays a vital role in hippocampus synaptic plasticity and that a similar mechanism may underlie neurological disorders in aging and hypogonadal men.

Abstract P084: Sex Differences In Testosterone On Interleukin-6 At Baseline And In Response To Mental Stress

Introduction: Young and middle-aged women with ischemic heart disease are a high-risk group for morbidity and mortality particularly after a myocardial infarction (MI). This group exhibits higher concentrations of the inflammatory cytokine interleukin-6 (IL-6) at baseline and in response to mental stress compared to men. The reasons for these differences are unknown; however, sex hormones may play a role. While testosterone has been shown to have anti-inflammatory effects among men; the role of testosterone on inflammatory cytokines among women has been understudied, and no research has examined the influence of testosterone on IL-6 response to stress. Hypothesis: Among young and middle-aged patients with a recent MI, higher concentrations of testosterone have anti-inflammatory effects among men at baseline and in response to mental stress; but are associated with greater inflammation among women. Methods: We studied 269 patients 61 years old or younger who were hospitalized for a MI in the previous 8 months. We measured plasma IL-6 (pg/mL) before and 90 minutes after mental stress (speech task). Inflammatory response was defined as the difference between IL-6 levels 90-minutes post mental stress and resting values. Serum free testosterone (pg/mL) was measured before mental stress. Differences across sex and time were examined with mixed models for repeated measures after natural log-transformation of IL-6. Results: The mean age was 51 years (range: 26-61); 48% were women and 64% African American. Mean values of free testosterone among men and women were 12.6 pg/mL (range: 0.9-29.0) and 1.8 pg/mL (range: 0.3-15.6), respectively. After adjusting for demographic factors (age, race, income), lifestyle and medical history (BMI, hypertension, diabetes, depression) and medication use, the association of testosterone with the IL-6 response to stress differed by sex (p for testosterone-by-sex-by-time interaction = 0.06). Among men, higher levels of testosterone were associated with lower concentrations of IL-6 at rest (β = -0.04; p = &lt;.0001), but was attenuated after stress (β = -0.001; p = 0.93). This change in slopes across time or inflammatory response for men was significant (p = &lt;.0001). In contrast, among women, higher levels of testosterone tended to be associated with higher IL-6 at rest (β = 0.04; p = 0.07) and after stress (β = 0.04; p = 0.14), indicating no change between time points or inflammatory response to stress (p=0.75). Conclusions: Among young and middle-aged survivors of a recent MI, higher concentrations of free testosterone are associated with lower inflammation among men, but with an opposite trend of higher inflammation among women.

Relationship of serum testosterone with coronary artery disease in young adult males of Bangladesh

The incidence rate and mortality of coronary artery disease is obviously higher in men than in women, which may be related to the influence of serum testosterone. This cross-sectional study was conducted at Department of Laboratory Medicine in collaboration with Department of Cardiology, BSMMU and National Institute of Cardiovascular Diseases (NICVD), Dhaka from March 2020 to February 2021 to investigate the association of serum testosterone with coronary artery disease in young adult males in Bangladesh. Total 110 subjects from inpatient Department of Cardiology were enrolled, 60 were CAD patients and 50 were Normal Coronaries according to coronary angiography report. In this study, 60 patients with coronary artery disease were compared with 50 normal coronary subjects. Mean age in CAD group and normal coronaries was 37.72±2.73 and 37.48±2.54 years respectively. Hypertension, diabetes mellitus and dyslipidemia were significantly higher in CAD group. Total testosterone levels of CAD were significantly lower than those of normal coronaries (2.11±0.81ng/ml vs 2.94±0.78ng/ml). Among 60 CAD patients, 10 patients had single vessel disease, 17 patients had double vessel disease and 33 patients had triple vessel disease. There was significant association between the level of total testosterone and the number of affected vessels within CAD group (p=0.1). This study also showed that total testosterone level was negatively correlated with Gensini score. Serum total testosterone was significantly lower in patients with CAD compared to normal coronaries. Patients with lower total testosterone levels had higher Gensini score. Low level of total testosterone may be related to the develop- ment of coronary artery disease. BSMMU J 2021; 14(3): 67-73

Help or punishment: acute stress moderates basal testosterone's association with prosocial behavior

The gonadal hormone testosterone is well-recognized to facilitate various behaviors for obtaining social status. A good reputation (i.e. competitive, generous, and trustworthy) is of crucial importance for acquiring high social status. It is unclear which type of reputation is preferred by individuals under the influence of testosterone. Given that the recent dual-hormone hypothesis emphasizes the modulating effect of stress (cortisol) on the influence of testosterone, it would be intriguing to test the role of stress-induced cortisol in testosterone-related reputation seeking. To test this hypothesis, we induced acute stress in 93 participants with cold pressor test (CPT) paradigm (vs. control condition), and then they were instructed to play a third-party intervention game, in which they made decisions as an uninvolved, outside the third party to punish a violator, help a victim, or do nothing. Salivary samples were obtained to assess participants’ testosterone and cortisol levels. We split the testosterone concentration by median to low endogenous testosterone (LT) and high endogenous testosterone (HT). We found that HT individuals’ prosocial preferences did not affect by acute stress. They were more likely to choose punishment than helping under both stress and control conditions. In contrast, individuals with low testosterone were more inclined to help than punish under control conditions. Interestingly, acute stress brought behavior patterns of LT individuals closer to those of HT individuals, that is, they reduced their helping behavior and increased the intensity of punishments. In this preliminary study on the preference inducement of testosterone for different types of prosocial behaviors, we discuss the physiological mechanism of the relationship between testosterone and reputation and the implications of these results for the dual-hormone hypothesis. HIGHLIGHTS Low testosterone (LT) individuals were more inclined to help than punish. High testosterone (HT) individuals were more inclined to punish than help. The HT individuals' preferences for prosocial types were not affected by acute stress. Acute stress brought the behavior patterns of LT individuals closer to those of HT individuals.

Associations of Serum Testosterone and Sex Hormone-Binding Globulin With Incident Cardiovascular Events in Middle-Aged to Older Men.

The influence of testosterone on risk for cardiovascular events in men is uncertain. Previous observational studies of sex hormones and incident cardiovascular disease in men have reported inconsistent findings, limited by cohort sizes and different selection criteria. To analyze associations of serum total testosterone and sex hormone-binding globulin (SHBG) with incident cardiovascular events in men. Cohort study. UK Biobank prospective cohort. Community-dwelling men aged 40 to 69 years. Testosterone and SHBG were assayed, and free testosterone was calculated. Cox proportional hazards regression was done, with outcomes of incident myocardial infarction (MI), hemorrhagic stroke (HS), ischemic stroke (IS), heart failure (HF), and major adverse cardiovascular events (MACE), adjusted for sociodemographic, lifestyle, and medical factors. Of 210700 men followed for 9 years, 8790 (4.2%) had an incident cardiovascular event. After adjustment for key variables, lower total testosterone concentrations (quintile 1 vs. quintile 5) were not associated with incident MI (fully adjusted hazard ratio [HR], 0.89 [95% CI, 0.80 to 1.00]), HS (HR, 0.94 [CI, 0.70 to 1.26]), IS (HR, 0.95 [CI, 0.82 to 1.10]), HF (HR, 1.15 [CI, 0.91 to 1.45]), or MACE (HR, 0.92 [CI, 0.84 to 1.00]). Men with lower calculated free testosterone values had a lower incidence of MACE (HR, 0.90 [CI, 0.84 to 0.97]). Lower SHBG concentrations were associated with higher incidence of MI (HR, 1.23 [CI, 1.09 to 1.38]) and lower incidence of IS (HR, 0.79 [CI, 0.67 to 0.94]) and HF (HR, 0.69 [CI, 0.54 to 0.89]), but not with HS (HR, 0.81 [CI, 0.57 to 1.14]) or MACE (HR, 1.01 [CI, 0.92 to 1.11]). Observational study; single baseline measurement of testosterone and SHBG. Men with lower total testosterone concentrations were not at increased risk for MI, stroke, HF, or MACE. Calculated free testosterone may be associated with risk for MACE. Men with lower SHBG concentrations have higher risk for MI but lower risk for IS and HF, with causality to be determined. Western Australian Health Translation Network, Medical Research Future Fund, and Lawley Pharmaceuticals.

Influence of Training-induced Testosterone and Cortisol Changes on Skeletal Muscle and Performance in Elite Junior Athletes

This study aimed to investigate the influence of testosterone (T) and cortisol (C) on Skeletal Muscle Markers (SMM) at each phase of a track and field macrocycle. On a secondary basis, we also sought to determine whether C or T moderates the relationship between SMM and performance. Twenty-eighth (28) elite junior sprint athletes (15.48 ±1.89 years), and 13 non-athletic (16.15 ±1.51 years), age and gender-matched controls participated in this study. Isometric muscle strength (MS) and muscle thickness (MTH) were considered SMM. Salivary C and T levels, MS and MTH were collected between 2:30 and 3:00 p.m. before training sessions, twice during the preparatory phase [baseline (T1) and midway into the specific preparation period (T2)] and twice in competition phase [midway point of pre-competition (T3) and midway of the major competition period (T4)]. Performance data were collected during the competition phase only. No significant improvements in SMM were observed. T and T/C ratio significantly increased (p<0.05) across the season, while C levels increased relative to baseline only. While T levels did not significantly predict SMM at any phase, C levels significantly explained (p<0.05) a 60% and 74% variance in MTH and performance respectively. However, neither C nor T significantly moderated the relationship between SMM and performance. These findings suggest that raising T levels across a season may be more indicative of a response to training load, rather than a reflection of skeletal muscle adaptation. While training-induced C, which was demonstrated to have a greater influence on SMM is more sensitive to muscle function changes and performance compared to testosterone.

Structural covariance of amygdala subregions is associated with trait aggression and endogenous testosterone in healthy individuals

Many studies point toward volume reductions in the amygdala as a potential neurostructural marker for trait aggression. However, most of these findings stem from clinical samples, rendering unclear whether the findings generalize to non-clinical populations. Furthermore, the notion of neural networks suggests that interregional correlations in gray matter volume (i.e., structural covariance) can explain individual differences in aggressive behavior beyond local univariate associations. Here, we tested whether structural covariance between amygdala subregions and the rest of the brain is associated with self-reported aggression in a large sample of healthy young students (n = 263; 49% women). Salivary testosterone concentrations were measured for a subset of n = 40 male and n = 36 female subjects, allowing us to investigate the influence of endogenous testosterone on structural covariance. Aggressive individuals showed enhanced covariance between left superficial amygdala (SFA) and left dorsal anterior insula (dAI), but lower covariance between right laterobasal amygdala (LBA) and right dorsolateral prefrontal cortex (dlPFC). These structural patterns overlap with functional networks involved in the genesis and regulation of aggressive behavior, respectively. With increasing endogenous testosterone, we observed stronger structural covariance between right centromedial amygdala (CMA) and right medial prefrontal cortex in men and between left CMA and bilateral orbitofrontal cortex in women. These results speak for structural covariance of amygdala subregions as a robust correlate of trait aggression in healthy individuals. Moreover, regions that showed structural covariance with the amygdala modulated by either testosterone or aggression did not overlap, suggesting a complex role of testosterone in human social behavior beyond facilitating aggressiveness.

Influence of Testosterone on Different Aspects of Bird Behavior and Physiology

Influence of Testosterone on Different Aspects of Bird Behavior and Physiology