Changes In Testosterone Concentrations Research Articles

Glucose ingestion does not lower testosterone concentrations in men on testosterone therapy.

Oral calorie intake causes an acute and transient decline in serum testosterone concentrations. It is not known whether this decline occurs in men on testosterone therapy. In this study, we evaluated the change in testosterone concentrations following oral glucose ingestion in hypogonadal men before and after treatment with testosterone therapy. This is a secondary analysis of samples previously collected from a study of hypogonadal men with type 2 diabetes who received testosterone therapy. Study participants (n = 14) ingested 75 grams of oral glucose, and blood samples were collected over 2 h. The test was repeated after 23 weeks of intramuscular testosterone therapy. The mean age and body mass index of study volunteers were 53 ± 8 years and 38 ± 7 kg/m2, respectively. Following glucose intake, testosterone concentrations fell significantly prior to testosterone therapy (week 0, p = 0.04). The nadir of testosterone concentration was at 1 h, followed by recovery to baseline by 2 h. In contrast, there was no change in testosterone concentrations at week 23. The change in serum testosterone concentrations at 60 min was significantly more at week 0 than week 23 (-11 ± 10% vs 0 ± 16%, p = 0.05). We conclude that oral glucose intake has no impact on testosterone concentrations in men on testosterone therapy. Endocrinology societies should consider clarifying in their recommendations that fasting testosterone concentrations are required for the diagnosis of hypogonadism, but not for monitoring testosterone therapy.

What Happens in Male Dogs after Treatment with a 4.7 mg Deslorelin Implant? I. Flare up and Downregulation.

Simple SummaryUntil now, information about the “flare up” and the time to downregulation in male dogs after treatment with a 4.7 mg deslorelin implant is strongly limited, regarding testosterone concentrations, testicular and prostatic volume and semen quality. The aim of this study was to provide detailed insights into these open questions. GnRH and hCG stimulation tests were performed to gain further insights into testicular endocrine function. Seven male beagle dogs were treated with a 4.7 mg deslorelin implant, and three animals were treated with saline, representing the controls. In deslorelin-treated dogs, first basal testosterone concentrations were observed earliest on D7 and latest on D28 after treatment. Infertility—based on the lack of semen or spermatozoa— was diagnosed earliest on D35 and latest on D77. After five months, the treatment was still effective in six dogs but was reversed in one deslorelin-treated dog.Although registered since 2007, knowledge about changes in testosterone concentrations (T), testicular and prostatic volumes (TV, PV) and semen quality, as well as the time point of infertility following treatment with a 4.7 mg deslorelin (DES) slow-release implant, is limited. Therefore, seven sexually mature male dogs were treated with DES (TG); three male dogs treated with saline served as controls (CG). The study assessed local tolerance, TV, PV, semen parameters and T subsequent to GnRH/hCG stimulation in regular intervals. Local tolerance was good. In TG, T was increased right after treatment, but decreased four hours afterwards. Subsequently, TV, PV, semen quality and T decreased over time in TG, but not CG. T was basal (≤0.1 ng/mL) from D28 onwards. Response to GnRH/hCG stimulation was variable, with two TG dogs having increased T post-stimulation on all study days independent of pre-treatment concentrations. A(zoo)spermia in TG was observed from D35–D77 in all seven dogs. Whereas treatment was still effective in six TG dogs five months after implant insertion, it was fully reversed in one dog in terms of T and spermatozoa on the last examination. These results indicate high variation in individual dogs, necessary to consider when advising dog owners.

Changes in serum testosterone and anti-Müllerian hormone concentration in bulls undergoing scrotal insulation

While changes in semen quality after heat stress are well characterized in the bull, changes in endocrine function have not been critically evaluated. It was hypothesized here that scrotal insulation results in alterations in Sertoli cell and Leydig cell function, as measured by changes in serum testosterone and anti-Müllerian hormone (AMH) concentration. Scrotal insulation bags were placed in 10 bulls for 8 d. Blood was collected on days -22 and -2, and weekly from days 5 to 96 (day 0 = first day of scrotal insulation) for measurement of serum concentration of AMH and testosterone using ELISA. The concentration of AMH decreased on day 5, followed by an increase on day 54 (P = 0.014). When AMH concentration was normalized to pre-insulation values, the percent increase in serum concentration of AMH was significant between days 26 and 54, with another peak at 75 d (P = 0.031). The serum concentration of testosterone (P = 0.0001) and the percentage of change in testosterone concentration (P < 0.0001) increased on day 5, followed by a decrease from days 33 to 96. Scrotal insulation was associated with Sertoli and Leydig cell dysfunction, as measured by serum testosterone and AMH concentration. The persistently low concentration of testosterone at the end of the study suggests a long term effect of scrotal insulation on Leydig cell function.

Relationship between the seasonal changes in plasma testosterone and thyroxine concentrations with sperm cryoresistance in Gabon bucks.

Gabon buck is a breed with little marked seasonality in our latitude (Uruguay, 35° SL). The role of thyroid hormones on the regulation of their seasonal reproductive activity and sperm cryoresistance is unknown. Seasonal changes in testosterone concentration can affect sperm variables, but the influence of testosterone changes on sperm cryoresistance in other species determines that the recommended time for freezing sperm does not coincide with the period with greater sperm fresh quality. The objectives of the present work were to (i) describe the thyroxine seasonal pattern in bucks in a subtropical area, and its association with annual changes in sperm variables; (ii) relate the seasonal changes of testosterone and thyroxine concentrations with the sperm cryoresistance. For one year, semen of 10 adult Gabon bucks was collected by electroejaculation every two weeks. After sperm selection, the sample was frozen. Testosterone and thyroxine concentrations varied according to the month (P < 0.0001). Testosterone reached the greatest values in April (P < 0.0001) and May (P < 0.0001) and thyroxine reached minimum values (P < 0.0001) in the same months. During these months, a negative correlation ratio (CR) was found between testosterone concentration and CR-functional membrane (R = - 0.50; P < 0.0001). CR values for most sperm variables decreased during March-May, coinciding with the presence of maximum testosterone concentrations. In conclusion, high testosterone levels are associated with the worst sperm response to freezing-thawing process. Thyroxine concentrations have a strong seasonal pattern, but there was no relationship to sperm cryoresistance.

Testosterone stimulates perineuronal nets development around parvalbumin cells in the adult canary brain in parallel with song crystallization

Perineuronal nets (PNN) of the extracellular matrix are dense aggregations of chondroitin-sulfate proteoglycans that usually surround fast-spiking parvalbumin-expressing inhibitory interneurons (PV). The development of PNN around PV appears specifically at the end of sensitive periods of visual learning and limits the synaptic plasticity in the visual cortex of mammals. Seasonal songbirds display a high level of adult neuroplasticity associated with vocal learning, which is regulated by fluctuations of circulating testosterone concentrations. Seasonal changes in testosterone concentrations and in neuroplasticity are associated with vocal changes between the non-breeding and breeding seasons. Increases in blood testosterone concentrations in the spring lead to the annual crystallization of song so that song becomes more stereotyped. Here we explore whether testosterone also regulates PNN expression in the song control system of male and female canaries. We show that, in both males and females, testosterone increases the number of PNN and of PV neurons in the three main telencephalic song control nuclei HVC, RA (nucleus robustus arcopallialis) and Area X and increases the PNN localization around PV interneurons. Singing activity was recorded in males and quantitative analyses demonstrated that testosterone also increased male singing rate, song duration and song energy while decreasing song entropy. Together, these data suggest that the development of PNN could provide the synaptic stability required to maintain the stability of the testosterone-induced crystallized song. This provides the new evidence for a role of PNN in the regulation of adult seasonal plasticity in seasonal songbirds.

The Stair Climb Power Test as an Efficacy Outcome in Randomized Trials of Function Promoting Therapies in Older Men.

Standardization of performance-based physical function measures that are reliable and responsive to intervention is necessary for efficacy trials of function promoting anabolic therapies (FPTs). Herein, we describe a standardized method of measuring stair climbing power (SCP) and evaluate its ability to assess improvements in physical function in response to an FPT (testosterone) compared to gait speed. We used a 12-step SCP test with and without carrying a load (loaded, LSCP or unloaded, USCP) in two testosterone trials in older men. SCP was determined from mass, total step-rise, and time of ascent measured with an electronic timing system. Associations between SCP and leg press performance (strength and power), testosterone levels, and gait speed were assessed. Test-retest reliability was evaluated using interclass correlation and Bland-Altman analyses. Baseline SCP was negatively associated with age and positively with leg strength and power and gait speed. Both tests of SCP were safe and showed excellent reliability (intra-class correlation 0.91-0.97 in both cohorts). Changes in testosterone concentrations were associated with changes in USCP and LSCP, but not gait speed in mobility-limited men. Changes in leg press performance were associated with SCP in both trials. Both USCP and LSCP are safe and have high test-retest reliability. Compared to gait speed, SCP is associated more robustly with leg press performance and is sensitive to testosterone therapy. The LSCP might be a more responsive outcome than gait speed to evaluate the efficacy of FPT in randomized trials.

Testicular Color Doppler Ultrasonography in Barki Rams

The aim of the present study was to determine the blood flow dynamics of the testes of pre and post pubertal clinically normal Barki rams. Rams (n=8) were divided into two equal groups according to age. The first group was pre-pubertal rams (aged 4-6 months) and the second group was post pubertal sexually mature rams (aged 18-24 months). Doppler indices such as resistive index (RI), pulsatility index (PI) of the supra-testicular artery (STA) and marginal artery (MA) were measured by color and spectral Doppler ultrasonography of the scrotum and spermatic cord region. Blood samples were collected and serum testosterone level was evaluated. Results revealed that there was no significant difference (p > 0.05) between the two age groups of Barki rams in blood flow parameters of supra-testicular artery and marginal artery. Even though, Serum testosterone was significantly higher in the post pubertal group (p < 0.05). In conclusion, the sexual maturity in the rams was associated with significant changes in testosterone concentration but not in Doppler indices. Moreover, Doppler ultrasound can be used during the breeding soundness reproductive examination and before reproductive surgical interference in Barki rams.

Ultrasonographic, Hormonal, Morphological And Morphometric Correlate Studies of Induced Testicular Pathology In West African Dwarf Goat Bucks.

The study was carried out to evaluate the significance of ultrasound in the early detection of testicular pathology in the West African Dwarf (WAD) buck; hormonal, morphological and morphometric studies were used as correlates. Twelve matured WAD bucks divided into two groups (of 6 per group); A—control, B — bucks with right testis spermatic cord ligated for four weeks were used for this study. Testicular ultrasound protocols were carried on the Longitudinal Planes (LP) and Transverse Planes (TP) on both testes. Blood samples were collected via the jugular vein twice a week for four weeks and assayed for testosterone, Luteinizing Hormone (LH) and Follicle Stimulation Hormone (FSH) concentrations. The testes were harvested after four weeks and carefully separated from the epididymides for gross and histological studies. Results revealed that 24 hours post induction of testicular pathology, inflammation of the right testes of the group B bucks was detected by ultrasound as hypo-echoic (dark) regions covering about two-third of the entire testis while the non-ligated testes appeared mostly homogeneously greyish on the TP. By the end of the fourth week the entire ligated testes were inflamed and appeared hypo-echoic with some areas of fibrosis on the TP and LP. The LH and FSH concentrations increased while there were no significant changes in testosterone concentrations. There were marked reduction in testicular and epididymal weights and sizes in group B bucks. The group B bucks testes showed complete loss of testicular architecture while the Leydig cells were intact. In conclusion, testicular ultrasound was valuable in the early detection of the induced testicular pathology (which hormonal, morphological and morphometric studies confirmed), hence should be adopted as part of the BSE programme of the WAD buck.

The assessment of testosterone and radioisotopic index of bone metabolism and bone mineral density in men with testosterone deficiency after one year of testosterone therapy.

Testosterone deficiency in men is characterized by typical symptoms of hypogonadism and negative influence on the preservation of bone mass. In this study, we analysed the relationship between testosterone concentration and bone metabolism. Moreover, we assessed the impact of one-year compensation of testosterone deficiency in elderly men on bone metabolism and bone mineral density. Radioisotopic methods of bone metabolism assessment provide new research opportunities. Men with total testosterone concentration (TT) ≤ 3 ng/ml were included into this study. Patients with disorders or injuries of bone system, elevated prostate-specific antigen (PSA), enlarged prostate, disorders of thyroid and liver, diabetes mellitus or a history of chemotherapy as well as those treated for a long time with antibiotics were excluded from this study. The results of 50 men aged 57.52 ± 6.71 years obtained before the treatment (I test) and after one year of oral testosterone supplementation (test II) were analysed in this study. The following examinations and analyses were performed: interview and physical examination, orthopaedic, neurological and urological consultations, blood biochemistry, determination of hormones levels, assessment of Testosterone Deficiency Syndrome (TDS), densitometric and radioisotope assessment of bone metabolism. Moreover, radioisotopic index of bone metabolism was calculated. Testosterone therapy with oral preparation Undestor Testo Caps (Organon) containing 40 mg of testosterone lasted for 12 months. Statistical analysis was performed using Statistica 12 and Excel 2010 programs. Correlations between results before and after treatment were analysed. After 12 months of treatment, testosterone concentration increased by mean 78% and the level of luteinizing hormone (LH) decreased by 62%. TDS index increased from 0.53 ± 0.21 (in test I) to 1.91 ± 0.60 (in test II). After the therapy this index was significantly higher in all men (p < 0.0001). Moreover, BMD was also improved following therapy, however, the difference between test I and II was statistically insignificant. The greatest change was found in case of IBM (Index of Bone Metabolism). We observed a positive correlation between IBM and BMD before treatment (r = 0.7991), however, its strength decreased after one-year therapy (r = 0.6757). In our opinion, IBM is more sensitive than other methods of the assessment of changes occurring in bone system under the influence of testosterone therapy. The observed changes in IBM were proportional to changes in testosterone concentration. Testosterone level, TDS and radioisotopic assessment of bone metabolism may be used as prognostic and therapeutic factors of osteoporosis and bone fractures in elderly men.

Acute Testosterone Deficiency Alters Adipose Tissue Fatty Acid Storage.

Although the long-term effects of testosterone on adipose tissue lipid metabolism in men have been defined, the short-term regulation of these effects is not well understood. We examined the effects of acute testosterone withdrawal on subcutaneous abdominal and femoral adipose tissue fatty acid (FA) storage and cellular mechanisms. This was a prospective, randomized trial. Mayo Clinic Clinical Research Unit. Thirty-two male volunteers ages 18 to 50 participated in these studies. Volunteers were randomized to receive (1) no treatment (control), (2) injections (7.5 mg) of Lupron®, or (3) Lupron and testosterone (L+T) replacement for 49 days, resulting in 4 weeks of sex steroid suppression in the Lupron group. We measured body composition, fat cell size, adipose tissue meal FA and direct free FA storage, lipoprotein lipase (LPL), acyl coenzyme A synthetase (ACS), diacylglycerol acyltransferase activities, and CD36 content. Compared with control and L+T groups, acute testosterone deficiency resulted in greater femoral adipose tissue meal FA storage rates, fasting and fed LPL activity, and ACS activity. These results suggest that in men, testosterone plays a tonic role in restraining FA storage in femoral adipose tissue via suppression of LPL and ACS activities. FA storage mechanisms in men appear sensitive to short-term changes in testosterone concentrations.

Effects of label-dose permethrin administration in yearling beef cattle: I. Bull reproductive function and testicular histopathology

Pyrethroid administration to a wide variety of laboratory animals has been shown to cause detrimental effects on male fertility, including sperm quality, by means of endocrine disruption. The objective of this experiment was to study the effects of a commercial, permethrin-containing pour-on product on reproductive variables and testicular histopathology of yearling beef bulls. Black Angus bulls (n = 60; aged 369 ± 17 days; 511 ± 33 kg; 6.2 ± 0.5 body condition scores) were assigned to either (1) saline control (CON) or (2) permethrin pour-on administered at label dose (PYR). Blood samples were collected, and industry standard breeding soundness examinations (BSE), via electroejaculation, were performed on all bulls at 5 days before and 14 days after treatment. Progressive sperm motility and eosin-nigrosin–stained sperm were analyzed using high-power phase-contrast microscopy. Plasma testosterone concentrations were analyzed via radioimmunoassay. Bulls were slaughtered at 34 days, and one testicle per bull was randomly collected for histologic examination. Change in sperm motility between BSEs was not different because of treatment; sperm morphology however improved across treatments, but PYR bulls had less improvement in percent of head (P < 0.001) sperm abnormalities compared to CON, resulting in less improvement of primary abnormalities (P = 0.04). Nonetheless, morphological differences did not change the overall outcome for satisfactory breeder status. Change in testosterone concentration did not differ because of treatment. Histopathologic examination identified that testicular degeneration and tubule diameter did not differ as a result of treatment. It should be noted, however, that degeneration score (higher score having more degeneration) was positively correlated with primary abnormalities (P < 0.01; r = 0.35) and negatively correlated with normal sperm cells (P < 0.001; r = −0.43). In summary, these data indicate that a single use of permethrin at label dose in yearling Angus bulls results in minimal detrimental effects on sperm morphology but not to a degree that impacts the ability of bulls to pass a standard BSE.

Vitamin D, sex hormones and anaemia in men – is there an influence of cholecalciferol supplementation on haemoglobin concentrations or regulation of sex hormones in male haemodialysis patients? A pilot study

Introduction. Active metabolites of vitamin D, as well as androgens, may play a substantial role in the correction of anaemia caused by chronic kidney disease. Aim. Aim of the study was to analyze the association among vitamin D metabolite – 25(OH)D, sex hormones and anaemia and assess the influence of vitamin D supplementation on haemoglobin concentrations, and sex hormones levels in male haemodialysis patients. Material and methods. The study was performed in male patients on haemodialysis at the Diaverum Dialysis Unit at Ceglowska Street in Warsaw. In 18 eligible patients aged 35-65 who gave informed consent, out of the total of 81, concentrations of 25(OH)D were measured. All patients had vitamin D deficiency. Thus, in all patients included in the study cholecalciferol was supplemented for three months in the dose adjusted to the vitamin D deficiency. During the study the complete blood count, parameters of iron, calcium and phosphate homeostasis, and concentrations of sex hormones were measured. Results. Normalization of 25(OH)D concentration was achieved in 11out of 16 patients who completed the study (68.75%). In 8 patients (50%) a significant increase in haemoglobin concentration was observed (P = 0.001). Baseline concentrations of 25(OH)D correlated strongly with total testosterone levels and weakly with haemoglobin concentrations. Moreover, free testosterone index (FTI) moderately correlated with haemoglobin concentrations. Substantial increase in androstenedione concentrations and a decrease in LH, but no significant changes in testosterone concentrations or FTI values were observed during cholecalciferol supplementation. Conclusions. Cholecalciferol supplementation in vitamin D deficient men on haemodialysis effectively normalized its serum concentration. Strong correlation between 25(OH)D and testosterone concentrations may suggest pathophysiologic association, however, the influence of vitamin D supplementation on testosterone and haemoglobin levels seems clinically negligible.

Salivary hormones and IgA in relation to physical performance in football

Salivary biomarkers have shown to be useful to assess physiological stress in football, but their relationship with physical performance is unknown. The aims of this study were to investigate the effect of a football match on salivary cortisol, testosterone and immunoglobulin A (IgA) concentrations in elite footballers, and to examine the relationship of physical performance during the match to these biomarkers. Nine elite football players were assessed before, during and after a friendly international match. Physical performance during the match was measured by time-motion analysis, whilst salivary cortisol, testosterone and IgA were measured before and 10 min post-match. The results showed that players covered an average of 9463 ± 458 m during the match. Salivary cortisol did not change post-match. Testosterone and IgA concentrations decreased by 30.6% and 74.5%, respectively. The testosterone/cortisol (T/C) ratio decreased by 64.2% after the match. Changes in testosterone concentrations correlated (r = 0.85) with distance covered. Pre- and post-match testosterone levels correlated with post-match IgA concentrations (r = 0.8 and 0.89, respectively). These results suggest that a football match induces catabolic stress as indicated by the decreased T/C ratio. It seems that footballers with smaller decreases in testosterone levels covered more distance and decreased their immune function less.

Individual Differences in Testosterone Predict Persistence in Men

Persistence is an important predictor of future successes. The present research addresses the relationship between testosterone and persistence in men. One hundred eighteen men were randomly assigned to win or lose a competitive number tracing task against a confederate or complete the task alone in a non–competitive control condition. Saliva samples were collected prior to and after the competition or control conditions. Participants were then given a maximum time of 30 min to spend attempting to solve unsolvable puzzles, with the option to quit at any time. In contrast to our prediction, changes in testosterone concentrations in response to the competitive interaction did not predict persistence behaviour. However, individual differences in testosterone concentrations (pre–competition/non–competition) were positively correlated with persistence. These findings are the first to examine associations between neuroendocrine function and persistence behaviour in people and suggest that testosterone should also be considered when predicting persistence–related outcomes. Copyright © 2014 European Association of Personality Psychology

Effects of testosterone administration on cognitive function in hysterectomized women with low testosterone levels: a dose–response randomized trial

To determine the dose-dependent effects of testosterone administration on cognition in women with low testosterone levels. 71 hysterectomized women with or without oophorectomy with total testosterone <31 ng/dl and/or free testosterone <3.5 pg/ml received a standardized transdermal estradiol regimen during the 12-week run-in period and were then randomized to receive weekly intramuscular injections of placebo, 3, 6.25, 12.5, or 25 mg testosterone enanthate for 24 weeks. Total testosterone was measured in serum by LC-MS/MS, and free testosterone levels were measured by equilibrium dialysis. Cognitive function was evaluated using a comprehensive battery of standardized neuropsychological tests at baseline and 24 weeks. 46 women who had baseline and end-of-treatment cognitive function data constituted the analytic sample. The five groups were similar at baseline. Mean on-treatment nadir total testosterone concentrations were 15, 89, 98, 134, and 234 ng/dl in the placebo, 3, 6.25, 12.5, and 25 mg groups, respectively. No significant changes in spatial ability, verbal fluency, verbal memory, or executive function were observed in any treatment arm compared to placebo even after adjustment for baseline cognitive function, age, and education. Multiple regression analysis did not show any significant relation between changes in testosterone concentrations and change in cognitive function scores. Short-term testosterone administration over a wide range of doses for 24 weeks in women with low testosterone levels was neither associated with improvements nor worsening of cognitive function.

Changes in the Immunolocalization of Steroidogenic Enzymes and the Androgen Receptor in Raccoon (&lt;i&gt;Procyon lotor&lt;/i&gt;) Testes in Association with the Seasons and Spermatogenesis

The raccoon is a seasonal breeder with a mating season in the winter. In a previous study, adult male raccoons exhibited active spermatogenesis with high plasma testosterone concentrations, in the winter mating season. Maintenance of spermatogenesis generally requires high testosterone, which is produced by steroidogenic enzymes. However, even in the summer non-mating season, some males produce spermatozoa actively despite low plasma testosterone concentrations. To identify the factors that regulate testosterone production and contribute to differences in spermatogenetic activity in the summer non-mating season, morphological, histological and endocrinological changes in the testes of wild male raccoons should be known. In this study, to assess changes in the biosynthesis, metabolism and reactivity of testosterone, the localization and immunohistochemical staining intensity of four steroidogenic enzymes (P450scc, P450c17, 3βHSD, P450arom) and the androgen receptor (AR) were investigated using immunohistochemical methods. P450scc and P450c17 were detected in testicular tissue throughout the year. Seasonal changes in testosterone concentration were correlated with 3βHSD expression, suggesting that 3βHSD may be important in regulating the seasonality of testosterone production in raccoon testes. Immunostaining of P450arom and AR was detected in testicular tissues that exhibited active spermatogenesis in the summer, while staining was scarce in aspermatogenic testes. This suggests that spermatogenesis in the raccoon testis might be maintained by some mechanism that regulates P450arom expression in synthesizing estradiol and AR expression in controlling reactivity to testosterone.

Prolonged consumption of flaxseed flour increases the 17β-estradiol hormone without causing adverse effects on the histomorphology of Wistar rats’ penis

Consumption of foods rich in phytoestrogens such as flaxseed has increased due to its chemoprotective effects, especially those related to the cardiovascular system. The flaxseed has components that can interfere with development of male reproductive system. This study aims to investigate the possible effects of prolonged consumption of flaxseed flour on hormonal and histomorphologic penis parameters of adult Wistar rats. Rat dams were divided into two groups during lactation period: the control group that was fed with diet based on casein and the flaxseed group that was fed with diet based on casein containing 25% of flaxseed . At weaning, 10 male offspring from each group continued to receive the experimental diets until 250days old. Rats fed with diet containing flaxseed showed increased concentrations of 17β-estradiol (p=0.01) but no changes in testosterone concentrations. With regard to histomorphometric analysis of the penis, supplemented rats had lower values for the total area of the corpus spongiosum (p=0.01). All other analyzed parameters wer e similar as the control. Results showed that the use of flaxseed flour did not cause adverse effects on the penis morphology but increases the 17β-estradiol hormone, when consumed in integral form for a prolonged period.

Reversible suppression of sexual activity in tomcats with deslorelin implant

The aim of the study was to assess the efficacy of using a Gn-RH agonist implant (deslorelin, 4.7 mg, Suprelorin) to control sexual activity of male cats and reestablishment of sexual function after the implant removal 4 mo after placement. Using a control group (Group 1, n = 5), 22 domestic tomcats were given the implant subcutaneously in the region of the right shoulder blade and were then divided into two treatment groups. Animals in Group 2 (n = 14) were observed from the date of implant surgery and the observation lasted for 4 mo. In Group 3 (n = 8) all animals were monitored from the date of implant surgery. Then, after 4 mo, all implants were removed and the toms were observed for a further 4 mo. In all animals during their first visit and then in 1-mo intervals, changes in testosterone concentrations were assessed before (T0) and 4 h after (T4) human chorionic gonadotropin (HCG) administration and testis size was measured. In all tomcats, semen collection was performed, using an electroejaculator, in the course of the first visit and then in 2-mo intervals or at the end of observation. Total sperm count was determined in each semen sample. Two to four animals were castrated at weeks 4, 8, 12, 16, 20, 24, 28 and 32 and histologic assessment of the testes was performed.By evaluation of 200 cross sections of seminiferous tubules, the degree of spermatogenic suppression was assessed and animals in Groups 2 and 3 were assigned into groups according to most tubules with the most developed germ cell observed: G1, spermatocytes; G2, round spermatids; G3, elongating spermatids and G4, elongated spermatids. The mean area of Leydig-cell nuclei was calculated.In animals in Group 2, suppression after implant insertion was monitored. T4 concentrations, testis size, and total sperm count gradually decreased (P < 0.01; P < 0.01; and P < 0.05, respectively) within 4 mo after implantation. Histologic evaluation showed a high individual variation in the degree of suppression of spermatogenesis.In animals in Group 3, the implant was removed 4 mo after insertion and the return of sexual activity was monitored. Within 4 mo, T4 concentration and total sperm count increased to the physiological values of intact toms. Testes gradually increased in size and within 4 mo of implant removal almost reached pretreatment size. According to histologic evaluation of the seminiferous tubules, as early as 1 mo after implant removal, all animals were assigned to G4, with most tubules containing elongated spermatids as the most developed germ cells.Treatment with the long-term subcutaneous Gn-RH agonist implant was well tolerated and no adverse treatment-related effects were noted.These results demonstrated efficacy of 4.7 mg deslorelin implant (Suprelorin) with high variability of the effect onset in tomcats. Furthermore, the study revealed a strong need for complex examination, including testis size measurement, monitoring of hormonal changes, spermatological analysis and histologic evaluation, to declare the animal infertile. After the implant removal, all observed parameters confirmed the reversibility of the method and gradual return of sexual activity in toms.

Change in testosterone concentrations over time is a better predictor than the actual concentrations for symptoms of late onset hypogonadism

Background. Symptoms of late-onset hypogonadism (LOH) and concentrations of testosterone (T) and bioavailable testosterone (BT) were studied in relation to the data from the same men 5 years earlier.Methods. In 2008, 282 men, aged 60–82 years, answered a questionnaire regarding demographic data, medical history, different symptoms of LOH and the 10 questions from the ‘Androgen Decline in Aging Males (ADAM)-questionnaire’. Blood samples were analysed for concentrations of T and calculations were made for BT.Results. A total of 87.2% of the questionnaires were returned and analysed, and 75.2% of the responders gave blood samples. The oldest third of the men were most affected by LOH symptoms (p < 0.05). Both T and BT concentrations decreased during the 5 years (p < 0.05) but only the symptom ‘less strong erections’ changed significantly (p < 0.05). Men reporting one of the four specific symptoms from the ‘ADAM-questionnaire’ for the first time in 2008 had a higher loss of T and BT than men who had unchanged or fewer symptoms than that reported in 2003.Conclusions. The magnitude of the decrease in concentrations is a better predictor of LOH than are the actual concentrations of T and BT. A combination of symptoms predicts LOH better than any single symptom.

Changes in salivary testosterone concentrations and subsequent voluntary squat performance following the presentation of short video clips

Previous studies have shown that visual images can produce rapid changes in testosterone concentrations. We explored the acute effects of video clips on salivary testosterone and cortisol concentrations and subsequent voluntary squat performance in highly trained male athletes (n = 12). Saliva samples were collected on 6 occasions immediately before and 15 min after watching a brief video clip (approximately 4 min in duration) on a computer screen. The watching of a sad, erotic, aggressive, training motivational, humorous or a neutral control clip was randomised. Subjects then performed a squat workout aimed at producing a 3 repetition maximum (3RM) lift. Significant (P < 0.001) relative (%) increases in testosterone concentrations were noted with watching the erotic, humorous, aggressive and training videos (versus control and sad), with testosterone decreasing significantly (versus control) after the sad clip. The aggressive video also produced an elevated cortisol response (% change) and more so than the control and humorous videos (P < 0.001). A significant (P < 0.003) improvement in 3RM performance was noted after the erotic, aggressive and training clips (versus control). A strong within-individual correlation (mean r = 0.85) was also noted between the relative changes in testosterone and the 3RM squats across all video sessions (P < 0.001). In conclusion, different video clips were associated with different changes in salivary free hormone concentrations and the relative changes in testosterone closely mapped 3RM squat performance in a group of highly trained males. Thus, speculatively, using short video presentations in the pre-workout environment offers an opportunity for understanding the outcomes of hormonal change, athlete behaviour and subsequent voluntary performance.