Basal Testosterone Concentrations Research Articles

The influence of body composition on the response to dynamic stimulation of the endocrine pituitary-testis axis

BackgroundTestosterone treatment is generally not recommended in men with obesity induced low serum testosterone. However, distinguishing this condition from overt testosterone deficiency in men with obesity where treatment should be initiated is a diagnostic challenge and tools to differentiate these conditions are scarce but could be of important clinical relevance.ObjectivesTo investigate the association between body composition and dynamic responses of the pituitary-testis axis in men.MethodsSingle-center cross-sectional study including 112 healthy men. Participants went through a full biochemical assessment of the pituitary-testis axis, and dynamic stimulatory tests of luteinizing hormone (LH) secretion (gonadotropin-releasing hormone (GnRH)-test) and testosterone secretion (choriogonadotropin (hCG)-test). A subset (N = 78) further had a DXA-scan performed.ResultsA higher body mass index (BMI) was associated with lower basal serum LH (BU = −0.44, 95% CI: −0.88–−0.01, p = 0.04). The GnRH-stimulated LH increase was not significantly associated with BMI (BU = −0.10, 95% CI: −0.72–0.51, p = 0.74). Furthermore, a high BMI was associated with low basal testosterone (BU −0.02, 95% CI: −0.03–−0.02, p < 0.001), and free testosterone (BU −15.0, 95% CI: −19.9–−10.0, p < 0.001) and men with overweight and obesity had significantly lower testosterone (9%, p = 0.003 and 24%, p < 0.001) and free testosterone (25%, p = 0.006 and 50%, p < 0.001) concentrations compared to men with normal weight. The HCG-stimulated testosterone increase was significantly less dependent on BMI compared to the influence of BMI on basal testosterone concentrations (p = 0.04 for the interaction).ConclusionsDynamic sex hormone responses following pituitary-testis axis stimulation were less dependent on BMI, compared to the influence of BMI on basal hormone concentrations and could potentially assist clinical decision making in patients with obesity suspected of testosterone deficiency.

Age-related decrease in serum dihydrotestosterone concentration is accompanied by impaired vascular status

IntroductionThe effect of androgens on the cardiovascular system in humans is ambiguous. Moreover, still little is known about the effects of the most potent androgen, dihydrotestosterone, on arterial stiffness and endothelial function. The aim of this study was to evaluate whether age-dependent alterations in serum concentration of dihydrotestosterone and its circulating metabolite are accompanied by changes in endothelial function and arterial stiffness. MethodsIn 12 young and 11 older men, basal serum concentrations of testosterone, dehydroepiandrosterone sulfate (DHAE-S), androstenedione (AE), dihydrotestosterone (DHT) and androstanediol glucuronide (ADG) were analyzed in relation to vascular status including cIMT — carotid intima media thickness, cAI — central augmentation index, crPWV — carotid radial pulse wave velocity, SI — stiffness index, endothelial and inflammatory markers. ResultsAlthough concentration of testosterone was not different between young and older group, it was demonstrated that DHT, DHEA-S, AE and ADG were significantly lower in older men in comparison to young men (p < 0.01). Interestingly the most surprising difference was found for DHT concentration, that was as much as 61 % lower in aged men that displayed significantly higher values of cIMT, AI, crPWV and SI (p < 10−4), suggestive of arterial stiffness. Furthermore, DHT was negatively correlated to all arterial wall parameters (cAI, crPWV, SI and cIMT), c-reactive protein (CRP) and hyaluronic acid (HA) concentration, as well as positively correlated to markers of endothelial function (MNA and 6-keto-PGF1α) in all studied individuals (n = 23). ConclusionsWe have shown that ageing leads to a significant decrease in DHT concentration that is accompanied by impaired arterial wall characteristics and worsened endothelial function. Therefore more attention should be paid to the DHT, DHEA-S and ADG concentrations as a biomarkers for vascular dysfunction in ageing men.

Does endoplasmic reticulum stress stimulate the apoptosis of granulosa cells in polycystic ovary syndrome?

The aim of this study was to determine whether endoplasmic reticulum (ER) stress is involved in the apoptosis of granulosa cells in patients with polycystic ovary syndrome (PCOS). A total of 116 patients undergoing in vitro fertilization/intracytoplasmic sperm injection cycles at the Binzhou Medical University Hospital IVF Center between September 2019 and January 2020 were enrolled in the study. Apoptosis of the granulosa cells in each patient was analyzed using flow cytometry, and progesterone and estrogen levels in the cell-culture fluid were measured by enzyme-linked immunosorbent assay. The expressions of X-box-binding protein 1 (XBP1(s)), activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), B-cell CLL/lymphoma 2 protein (Bcl-2), and Bcl-2 associated X protein (Bax) at the gene or protein level were analyzed using quantitative real-time polymerase chain reaction and Western blotting, respectively. In patients with PCOS, body mass index and basal serum concentrations of luteinizing hormone, testosterone (T), and anti-Mullerian hormone significantly increased (P < 0.05). The number of oocytes retrieed and the rate of clinical pregnancy after the first frozen embryo transfer also significantly increased (P < 0.05). Although apoptosis rate in the granulosa cells significantly increased in patients with PCOS, progesterone (P) and estrogen (E2) levels in the cell-culture fluid significantly decreased (P < 0.05). The apoptosis of granulosa cells was also found to affect blastocyst formation. Furthermore, the messenger ribonucleic acid (mRNA) expressions of XBP1(s), ATF6, CHOP, and Bax significantly increased in patients with PCOS, while that of Bcl-2 significantly decreased (P < 0.05). The protein expressions of CHOP and Bax significantly increased in patients with PCOS, while that of Bcl-2 significantly decreased (P < 0.05). After treatment of the granulosa cells with tauroursodeoxycholic acid, apoptosis rate and mRNA or protein expressions of XBP1(s), CHOP, and Bax significantly decreased, while the expression of Bcl-2 and levels of progesterone and estrogen significantly increased (P < 0.05). We conclude that ER stress could induce the apoptosis of granulosa cells in patients with PCOS. Cell apoptosis may decrease the number of blastocysts formed.

Low basal serum testosterone level is detrimental to the embryo implantation in the patients with severe endometriosis.

Androgens have been reported to be associated with female fertility. The mean serum testosterone concentration in the patients with endometriosis was reported to be significantly lower than that without endometriosis. Our study was designed to investigate the influence of basal serum testosterone levels on the clinical outcome of in vitro fertilization (IVF) in the patients with III-IV stage endometriosis. This retrospective cohort study included 407 patients with III-IV stage endometriosis diagnosed by laparoscopic surgery. We studied the association of the basal serum testosterone level and the reproductive outcome of IVF. The basal serum testosterone concentration was significantly higher in the pregnant group of patients with III-IV stage endometriosis. The further analyses demonstrated that the implantation rate of the basal serum testosterone concentration < 0.305 ng/mL group was significantly lower than the testosterone ≥ 0.305 ng/mL group (24.1% vs. 32.7%, p=0.007). The clinical pregnancy and live birth rate of the basal serum testosterone < 0.305 ng/mL group were also lower than that of the testosterone ≥ 0.305 ng/mL group. Both initial and total dose of gonadotropins in the testosterone <0.305 ng/mL group are significantly higher than that of the testosterone ≥0.305 ng/mL group. Our study demonstrated, for the first time, that the basal serum testosterone <0.305 ng/mL had an adverse impact on pregnancy outcomes of IVF-embryo transfer in the patients with III-IV stage endometriosis. Besides, the basal serum testosterone is also helpful in making individual stimulation protocol for the patients with advanced endometriosis before entering IVF cycles.

Basal Levels and hCG Responses of Serum Testosterone and Estrogen in Male Alpacas.

Steroid response to human Chorionic Gonadotropin (hCG) administration has been used in various species to study testicular function and for diagnostic purposes. In this study, two experiments were conducted to determine serum testosterone concentration response to administration of hCG and its correlation with testicular weight. In the second experiment the relationship between age, testosterone and estrogen response to hCG, and testicular histometry was in pre-pubertal and post-pubertal male alpacas. For experiment 1, males in two age groups (2 to 3 years, n = 9) and (4 to 7 years; n = 15) received 3,000 IU hCG IV, 36 to 48 h before castration. Serum testosterone concentration was determined before (T0), 1 h (T1), 2 h (T2), 8 h (T8), and 24 h (T24) after administration of hCG. Basal concentrations of serum testosterone was significantly different (P < 0.01) between age groups. Serum testosterone concentrations increased over time and doubled 2 h after treatment. The highest change (250 to 300% increase from T0) was observed at 8 h (3.5 ± 0.3 ng/ml). A significant correlation (P < 0.01; r = 0.64) was found between serum testosterone concentration and total testicular weight. For experiment 2, 60 males ranging in age from 6 to 60 months were used. Serum testosterone and estrogen was determined in samples taken just prior to and 2 h after administration of 3,000 IU hCG. Basal serum testosterone concentrations were very low (≤0.1 ng/mL) until 9 months of age then increased steadily with age. There was a significant variation amongst males within the same age group. Serum testosterone concentration increased by 2- to 4-fold 2 h after hCG injection (P ≤ 0.05). Males in the 13 to 14 months of age group had the highest rise. Estrogen concentration increased in response to hCG administration and was detected only in males with high testosterone. We conclude that administration of 3,000 IU of hCG IV can be used reliably to detect testicular tissue and study its steroidogenic activity. The response is correlated with testicular weight and Leydig cell number. Testicular growth and sensitivity to LH stimulation increases between the ages of 13 and 14 months. The aromatizing ability of Leydig cells increased significantly in post-pubertal male alpacas.

An Intramuscular Injection of Mixed Testosterone Esters Does Not Acutely Enhance Strength and Power in Recreationally Active Young Men

Purpose: Limited data are available on the acute performance-enhancing effects of single-dose administration of testosterone in healthy humans. Studies of testosterone administrations to healthy humans are rare due to the difficult nature and necessity of close clinical monitoring. However, our unique physiological experimental facilities combined with close endocrinological collaboration have allowed us to safely complete such a study. We tested the hypothesis that an intramuscular injection of 250 mg mixed testosterone esters (TEs) enhances physical performance in strength and power exercises acutely, measured 24 h after injection. Additionally, we investigated whether the basal serum testosterone concentration influences the performance in countermovement jump (CMJ), 30-s all out cycle sprint, and one-arm isometric elbow flexion.Methods: In a randomized, double-blind, placebo-controlled design, 19 eugonadal men received either a TE (n = 9, 23 ± 1 years, 183 ± 7 cm, 83 ± 10 kg) or a PLA (n = 10, 25 ± 2 years, 186 ± 6 cm, 82 ± 14 kg) injection. Hormonal levels and the performance in CMJ, 30-s all out cycle sprint, and one-arm isometric elbow flexion were measured before and 24 h after injection.Results: Firstly, an intramuscular injection of 250 mg mixed TEs did not enhance the vertical jump height in a CMJ test, peak power, mean power, and fatigue index in a 30-s all-out cycle sprint or rate of force development and maximal voluntary contraction in a one-arm isometric elbow flexion 24 h post-injection. Secondly, baseline testosterone levels appeared not to influence performance in strength and power exercises to a large extent in healthy, recreationally active young men.Conclusion: A single intramuscular injection of 250 mg mixed TEs has no acute ergogenic effects on strength and power performance in recreationally active, young men. This novel information has implication for basic physiological understanding. Whether the same applies to an elite athlete population remains to be determined. If so, this would have implications for anti-doping efforts aiming to determine the most cost-efficient testing programs.

Hormonal Changes in High-Level Aerobic Male Athletes during a Sports Season.

The aim of this study was to determine the possible changes in plasma of several hormones such as Luteinizing Hormone, Testosterone, Cortisol and Insulin in endurance runners during the sports season. Twenty-one high-level male endurance runners (22 ± 3.2 years, 1.77 ± 0.05 m) participated in the study. Basal plasma hormones were measured at four moments during the season (initial, 3, 6 and 9 months), and were analyzed using ELISA (enzyme-linked immunosorbent assay). Testosterone and Luteinizing Hormone (LH) suffered very significant decreases (p < 0.01) at 3 months compared with the beginning and an increase (p < 0.05) at 6 and 9 months compared with 3 months. Insulin level was significantly lower (p < 0.05) at 3, 6 and 9 months compared with the initial test. Insulin and cortisol were associated inversely (r = 0.363; β = −0.577; p = 0.017) and positively (r = 0.202; β = 0.310; p = 0.043), respectively, with the amount of km per week performed by the runners. There was a significant association between km covered at a higher intensity than the anaerobic threshold and I (r = 0.580; β = −0.442; p = 0.000). Our findings indicate that testosterone, LH and insulin were more sensitive to changes in training volume and intensity than cortisol in high-level endurance runners. Basal testosterone and LH concentrations decrease in athletes who perform a high volume of aerobic km in situations of low energy availability.

Depressive symptoms are not associated with long-term integrated testosterone concentrations in hair

Objectives The association between depressive symptomatology and endogenous testosterone levels is inconclusive. Large inter- and intra-individual testosterone differences suggest point measurements from saliva or serum to be inadequate to map basal testosterone concentrations highlighting the potential for long-term integrated testosterone levels from hair. Methods Using data from a prospective cohort study, a total of 578 participants (74% female) provided complete data on depressive symptomatology, clinical features, and hair samples for quantification of testosterone concentrations at baseline. Available data of three annual follow-up examinations were used for longitudinal analyses. Results Correlation analysis showed in both, men and women, hair testosterone across all the four time points not to be significantly related to depressive symptoms. Examined clinical features were not associated with testosterone levels, except for having a current diagnosis of a psychological disorder, which was associated with reduced testosterone levels in men, but not in women. Acceptable model fit for an autoregressive cross-lagged panel analysis emerged only for the female subsample suggesting inverse cross-relations for the prediction of testosterone by depressive symptomatology and vice versa. Conclusions Findings from this study add to the literature by showing no association between long-term integrated testosterone in hair and depressive symptomatology in men and women.

Role of Basal Hormones on Sweat Rate and Sweat Na+ Loss in Elite Women Soccer Players.

We aimed to determine whether basal concentrations of testosterone, cortisol or the ratio testosterone/cortisol were related to sweat Na+ loss, sweat Na+ concentration ([Na+]) and sweat rate during exercise. Twenty-two female elite soccer players participated in the study. Testosterone and cortisol were measured in blood samples before exercise. Sweat samples were collected during a training session (~20°C, ~30% RH, and ~0.55 m/s of wind speed) to measure sweat [Na+]. Sweat rate was determined by considering the difference between post-and pre-body weight, along with the amount of liquid consumed. During exercise, sweat Na+ loss (0.33[0.19] g/h) and sweat rate (0.49[0.20] L/h) were related to basal testosterone concentration (1.4[0.4] pg/mL) (r=0.54; r=0.55, respectively; p<0.05), but not with basal cortisol concentration (119.2[24.2] ng/mL) nor testosterone/cortisol ratio (0.012[0.003]) (p>0.05). However, when Na+ loss was adjusted to sweat rate, no association was found between Na+ loss and testosterone (p>0.05). In addition, no differences were found between players with high vs. low Na+ loss adjusted to sweat loss in menstrual phase or intensity during exercise (p>0.05). In conclusion, these results suggest that in these specific environmental conditions, basal levels of testosterone might increase sweat rate and therefore, the amount of Na+ lost during exercise in elite women soccer players.

Up-regulated FHL2 inhibits ovulation through interacting with androgen receptor and ERK1/2 in polycystic ovary syndrome.

BackgroundThe ovulatory dysfunction mechanisms underlying polycystic ovary syndrome (PCOS) are not completely understood. There is no effective therapy for PCOS so far.MethodsWe measured the expression of four and a half LIM domain 2 (FHL2) and other related-genes in human granulosa cells (hGCs) from patients with and without PCOS. To minimise the heterogeneity of patients with PCOS, we only included PCOS patients meeting all three criteria according to the revised Rotterdam consensus. The in vitro effects of FHL2 on ovulatory genes and the underlying mechanisms were examined in KGN cells. The role of FHL2 in ovulation was investigated in vivo by overexpressing FHL2 in rat ovaries via intrabursal lentivirus injection.FindingsIncreased FHL2 and androgen receptor (AR) expression and decreased CCAAT/enhancer-binding protein β (C/EBPβ) expression were observed in hGCs from patients with PCOS. FHL2 inhibited the expression of ovulation-related genes, including phosphorylated ERK1/2, C/EBPβ, COX2 and HAS2 in KGN cells. It was partially by interacting with AR to act as its co-regulator to inhibit C/EBPβ expression and by binding to ERK1/2 to inhibit its phosphorylation. Moreover, FHL2 abundance in hGCs was positively correlated with the basal serum testosterone concentration of patients with PCOS, and dihydrotestosterone (DHT)-induced FHL2 upregulation was mediated by AR signalling in KGN cells. Additionally, lentiviral-mediated functional FHL2 overexpression in rat ovaries for 1 week contributed to an impaired superovulatory response, displaying decreased numbers of retrieved oocytes and a lower MII oocyte rate. 3-week FHL2 overexpression rat models without superovulation led to acyclicity and polycystic ovary morphology.InterpretationOur findings provide novel insights into the mechanisms underlying the pathogenesis of PCOS, suggesting that FHL2 could be a potential treatment target for ovulatory obstacles in PCOS.FundNational Key Research and Development Program of China, National Natural Science Foundation, National Institutes of Health project and Shanghai Commission of Science and Technology.

Differences in Psychoneuroendocrine Stress Responses of High-Level Swimmers Depending on Autocratic and Democratic Coaching Style.

The aim of the present study was to analyse differences in the psychoneuroendocrine stress responses of high-level, young swimmers depending on whether an autocratic and democratic coaching style was applied. Modifications in cortisol and the motivational climate of 18 young swimmers (15.3 ± 1.86 years, 10 females and 8 males) were analysed before and after two training sessions with equivalent training loads but directed by two coaches applying different approaches, i.e., autocratic (A) and democratic (D). The basal testosterone levels of the coaches were also assessed. The basal testosterone concentration was higher in coach A than in coach D; the athletes perceived them as autocratic and democratic, respectively. Swimmers under coach A’s instructions showed higher cortisol levels, suggesting higher cortisol production related to coaching style. Furthermore, differences in the motivational climate concerning ego (i.e., athletes comparing their ability with that of other athletes) were observed with coach A, whereas differences in motivational climate concerning the task (i.e., athletes comparing their ability with their own past performance) were observed with coach D. Cognitive variables showed negative perceptions affecting athletes’ training experience and performance when they were screamed at or insulted by coach A. There were no gender or age differences in cortisol production or motivational climate. In conclusion, this study suggests that an autocratic coaching style modulates cortisol release in both genders, affecting young elite swimmers’ motivational climate and training experience.

Up-Regulated FHL2 Inhibits Ovulation Through Interacting with Androgen Receptor and ERK1/2 in Polycystic Ovary Syndrome

Background: The ovulatory dysfunction mechanisms underlying polycystic ovary syndrome (PCOS) are not completely understood. There is no effective therapy for PCOS so far. Methods: We measured the expression of four and a half LIM domain 2 (FHL2) and other related-genes in human granulosa cells (hGCs) from patients with and without PCOS. The in vitro effects of FHL2 on ovulatory genes and the underlying mechanisms were examined in KGN cells. The role of FHL2 in ovulation was investigated in vivo by overexpressing FHL2 in rat ovaries via intrabursal lentivirus injection. Findings: Increased FHL2 and androgen receptor (AR) expression and decreased CCAAT/enhancer-binding protein β (C/EBPβ) expression were observed in hGCs from patients with PCOS. FHL2 inhibited the expression of ovulation-related genes, including phosphorylated ERK1/2, C/EBPβ, COX2 and HAS2 in KGN cells. It was partially by interacting with AR to act as its co-regulator to inhibit C/EBPβ expression and by binding to ERK1/2 to inhibit its phosphorylation. Moreover, FHL2 abundance in hGCs was positively correlated with the basal serum testosterone concentration of patients with PCOS, and dihydrotestosterone (DHT)-induced FHL2 upregulation was mediated by AR signalling in KGN cells. Additionally, lentiviral-mediated functional FHL2 overexpression in rat ovaries for 1 week contributed to an impaired superovulatory response, displaying decreased numbers of retrieved oocytes and a lower MII oocyte rate. 3-week FHL2 overexpression rat models without superovulation led to acyclicity, polycystic ovary morphology and hormonal disorders. Interpretation: Our findings provide novel insights into the mechanisms underlying the pathogenesis of PCOS, suggesting that FHL2 could be a potential treatment target for ovulatory obstacles in PCOS. Funding: National Key Research and Development Program of China, National Natural Science Foundation, National Institutes of Health project and Shanghai Commission of Science and Technology. Declaration of Interest: The authors declare that they have no competing interests. Ethical Approval: The Institutional Review Board of the Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, reviewed and approved all procedures. All rat experiments were approved by the Institutional Review Board of Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University.

Basal Serum Cortisol and Testosterone/Cortisol Ratio Are Related to Rate of Na+ Lost During Exercise in Elite Soccer Players.

During exercise, the human body maintains optimal body temperature through thermoregulatory sweating, which implies the loss of water, sodium (Na+), and other electrolytes. Sweat rate and sweat Na+ concentration show high interindividual variability, even in individuals exercising under similar conditions. Testosterone and cortisol may regulate sweat Na+ loss by modifying the expression/activity of the cystic fibrosis transmembrane conductance regulator. This has not been tested. As a first approximation, the authors aimed to determine whether basal serum concentrations of testosterone or cortisol, or the testosterone/cortisol ratio relate to sweat Na+ loss during exercise. A total of 22 male elite soccer players participated in the study. Testosterone and cortisol were measured in blood samples before exercise (basal). Sweat samples were collected during a training session, and sweat Na+ concentration was determined. The basal serum concentrations of testosterone and cortisol and their ratio were (mean [SD]) 13.6 (3.3)pg/ml, 228.9 (41.4)ng/ml, and 0.06 (0.02), respectively. During exercise, the rate of Na+ loss was related to cortisol (r = .43; p < .05) and to the testosterone/cortisol ratio (r = -.46; p < .01), independently of the sweating rate. The results suggest that cortisol and the testosterone/cortisol ratio may influence Na+ loss during exercise. It is unknown whether this regulation depends on the cystic fibrosis transmembrane conductance regulator.

Evidence of the Exercise-Hypogonadal Male Condition at the 2011 Kona Ironman World Championships.

Prior research has illustrated that high volumes of aerobic exercise result in a reduction in basal concentrations of testosterone in men. Those studies were mostly conducted on recreational runners and identified reduced testosterone, but not concentrations low enough to be considered pathological. Therefore, the purpose of this study was to assess the basal concentrations of testosterone and cortisol in elite triathletes, as well as the impact of a World Championship race, on the acute responses of these hormones. A total of 22 men (age 40.6 [11.5]y, height 179 [6]cm, weight 77.0 [7.0]kg) who participated in the 2011 Ironman World Championships served as subjects. Resting blood samples were taken 2-4 d prior to provide a baseline (BL), as well as immediately, 1 d, and 2 d after the event and were later analyzed for total testosterone and cortisol concentrations. At BL, 9 men had a normal testosterone concentration, whereas 9 men fell within a "gray zone" and 4 other men demonstrated concentrations suggestive of deficiency. Testosterone was significantly lower than BL at 1 d (95% confidence interval [CI] 0.10-0.34, P < .001, ES = 0.53) and 2 d (95% CI 0.01-0.21, P = .034, ES = 0.35) after the event. Cortisol was significantly different from BL at immediate post (95% CI 1.07-0.83, P < .001, ES = 8.0). There were significant correlations between time and age (R = .68, P = .001), as well as BL testosterone and cortisol (R = .51, P = .015). Elite ultraendurance athletes may demonstrate not only reduced testosterone but also sometimes clinically low concentrations that could be indicative of androgen deficiency.

Androgen-Secreting Ovarian Tumors.

About 1% of ovarian tumors that comprise testicular cell types can cause hyperandrogenism followed by characteristic virilization. Androgenic group of tumors originated mainly from sex-cord stromal ovarian tumors are including steroid cell tumors, Leydig tumors, granulosa cell tumors, Sertoli cell tumors, Sertoli-Leydig cell tumors, gonadoblastomas, and some other rare forms as ovarian metastases from neuroendocrine tumors. Germline or somatic mutations in some genes like DICER1, STK11, and FOXL2 are associated with the development of some sex cord-stromal ovarian tumors. Basal serum testosterone concentrations above 7 nmol/L could indicate an androgen-secreting tumor. Other ovarian and adrenal androgens should be determined and functional endocrine testing including low-dose dexamethasone suppression test, gonadotrophin-releasing hormone (GnRH) agonist test, imaging methods, and selective venous sampling should be performed. Surgery is the first-line treatment for most of the tumors. Women who are not good surgical candidates could benefit from use of GnRH agonist to control hyperandrogenism. In some cases, chemotherapy and/or radiation therapy is required while some tumors respond on antiangiogenic agents used alone or in combination with chemotherapy. Metabolic implications and long-term outcomes of ovarian androgen-secreting tumors are unknown and require more detailed follow-up in multicentric and longitudinal clinical studies.

Role of RFRP-3 in the development of cold stress-induced polycystic ovary phenotype in rats

RFamide-related peptide (RFRP-3) is a regulator of GnRH secretion from the brain, but it can also act in human ovary to influence steroidogenesis. We aimed to study the putative local role of RFRP-3 in the ovary and its potential participation in the development of a polycystic ovary phenotype induced by chronic sympathetic stress (cold stress). We used adult Sprague–Dawley rats divided into control and stressed groups. In both groups, we studied the effect of intraovarian exposure to RFRP-3 on follicular development and plasma ovarian steroid concentrations. We also tested the effect of RFRP-3 on ovarian steroid production in vitro. Chronic in vivo intraovarian exposure to RFRP-3 decreased basal testosterone concentrations and cold stress-induced progesterone production by the ovary. In vitro, RFRP-3 decreased hCG-induced ovarian progesterone and testosterone secretion. Immunohistochemistry and mRNA expression analysis showed a decrease in Rfrp and expression of its receptor in the ovary of stressed rats, a result which is in line with the increased testosterone levels found in stressed rats. In vivo application of RFRP-3 recovered the low levels of secondary and healthy antral follicles found in stressed rats. Taken together, our data indicate a previously unknown response of hypothalamic and ovarian RFRP-3 to chronic cold stress, influencing ovarian steroidogenesis and follicular dynamics. Thus, it is likely that RFRP-3 modulation in the ovary is a key component of development of the polycystic ovary phenotype.

Effects of implants containing the GnRH agonist deslorelin on testosterone release and semen characteristics in Shetland stallions

The hypothesis in this study was continuous treatment of stallions with the GnRH agonist deslorelin inhibits reproductive functions. A 2-week pre-experimental period was followed by an 11-week deslorelin implant treatment. Stallions received 4.7 (D1, n = 7), or 18.8 mg deslorelin (D2, n = 5) or remained untreated (C, n = 5). Libido, sperm motility, membrane integrity, DNA fragmentation, estrogen receptors, basal plasma testosterone and Anti Muellerian hormone (AMH) concentrations were evaluated once weekly during the treatment period. The testosterone response to the GnRH agonist buserelin and hCG was evaluated twice. In Week 2, stallions in Group C but not Groups D1 and D2 responded to buserelin with testosterone release (P < 0.001), while in Week 9, stallions in Group C and D1 but not D2 released testosterone after buserelin administration (group P < 0.01, week P = 0.01). Stallions of all groups responded to hCG with testosterone release at both times of hCG administration (P < 0.001). The AMH concentration was similar in all groups. Deslorelin thus reduced pituitary responsiveness to GnRH but only with a large dose and this effect persisted for several weeks. Total sperm count increased transiently with the D2 treatment but not in stallions of the D1 and C groups after implant insertion (time P < 0.01, time x group P < 0.001). The percentage of ESR1-positive spermatozoa decreased transiently in Group D2 (time P < 0.01, time × group P < 0.01). There was no difference among groups at any time during the study in percentage of motile and membrane-intact spermatozoa and sperm with DNA fragmentation. In conclusion, deslorelin implants modulate pituitary function in stallions but not to an extent that affects testicular function.

Intrasexual competition mediates the relationship between men's testosterone and mate retention behavior

Previous research has established a link between testosterone concentrations in males and their mating effort as it relates to their mate seeking behaviors. However, very little research has analyzed how variability in basal testosterone concentration of males affects their mating effort once they have secured a romantic partner. In a sample of undergraduate men, the relationship between testosterone, intrasexual competitiveness, and mate retention behavior was examined. Results showed that higher basal testosterone predicted more self-reported mate retention effort. This relationship was mediated by intrasexual competitiveness, such that high T men reported more intrasexual competitiveness, which when included in the model predicted mate retention, and reduced the initial T – mate retention relationship to statistical non-significance. When examined separately, this mediation effect applied specifically to cost-inflicting, rather than benefit-provisioning, mate retention behavior. These are the first findings to link T to mate retention effort and to identify intrasexual competitiveness as a mechanism which might account for this relationship.

Age related changes in basal concentrations of FSH, LH and testosterone in indigenous and crossbred bovine males

Collectively, the findings of the present study revealed that the concentrations of both FSH and LH were highest at 18 months of age in crossbred males, while in indigenous males, the FSH and LH concentrations were highest at 18 and 24 month of age, respectively. Higher concentrations of testosterone were observed at 18 months of age in crossbred males and at 24 months of age in indigenous males. These findings may explain the endocrinological support for comparatively late sexual maturity in indigenous males.

Circadian variations in peripheral levels of growth hormone and testosterone in male Murrah buffaloes

The aim of this study was to investigate the endocrine profiles of growth hormone (GH), testosterone and their interrelationship in prepubertal, pubertal and orchiectomised male Murrah buffaloes under starving conditions. The prepubertal and pubertal buffaloes were subjected to frequent blood sampling over 24 h at an interval of 1 h, whereas in orchiectomised buffaloes, the blood samples were collected over 18 h. Irrespective of group, the GH concentrations fluctuated in an episodic manner over 24 h and the fluctuations did not exhibit a consistent pattern between the animals of each group. The mean basal and peak concentrations of GH did not differ significantly (p > 0.05) among the groups. A significant (p > 0.0001) difference in testosterone concentrations was observed between prepubertal and pubertal groups. The differences in mean basal and peak testosterone concentrations between the prepubertal and pubertal groups were also significant (p < 0.01). The associations between testosterone and GH levels in both prepubertal (r = 0.15; p > 0.05) and pubertal (r = −0.37; p > 0.05) buffaloes were non-significant. The possible reasons for erratic episodic pattern of GH secretion will be discussed.