Home About us Contact
|
Home About us Contact | ||
|
|
||
Testosterone Concentrations (testosterone + concentration)
Kinds of Testosterone Concentrations Selected AbstractsReproductive Development of Santa Inês Rams During the First Year of Life: Body and Testis Growth, Testosterone Concentrations, Sperm Parameters, Age at Puberty and Seminal Plasma ProteinsREPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2010CEA Souza Contents We have investigated the reproductive development of the tropically adapted Santa Inês ram, the most common hair sheep in Brazil. From 8 to 48 weeks of age, 16 animals were evaluated for body and testis growth, semen parameters, testosterone concentrations and seminal plasma proteins, using two-dimensional SDS-PAGE. Animals were weaned at 30 days and kept in feedlots thereafter, receiving hay, concentrate (18% of crude protein) and mineral supplement. Body weight increased from 12.3 ± 0.7 to 54.3 ± 1.6 kg between 8 and 48 weeks (p < 0.05), but changes in thoracic perimeter and scrotal circumference were non-significant after 36 weeks (p > 0.05). The percentage of motile sperm increased slowly until 23 weeks and more rapidly after that age, but significant changes in progressive motility occurred after 25 weeks. Presence of abnormal sperm related inversely to age. Most significant changes in sperm concentration occurred between 38 and 44 weeks (0.38 ± 0.05 to 1.14 ± 0.24 × 109 cells/ml, p < 0.05) and testosterone reached its highest concentrations at 42 weeks, decreasing afterwards. Rams reached puberty at 28.2 ± 0.8 weeks. The number of protein spots on seminal plasma gels was similar from 15 to 18 weeks (45 and 47 spots; p > 0.05), increased until 24 weeks (141 spots) and 28 weeks (170 spots; p < 0.05) and remained without significant (p > 0.05) changes from 28 to 48 weeks (186 ± 10 spots). Furthermore, the intensity of selected spots on 2D maps increased (p < 0.05) between 15 and 28 weeks, which preceded or coincided with the main developmental changes in sperm motility and percentage of defective sperm in the ejaculates. These results will support future studies designed to characterize specific seminal plasma proteins whose expression relate to the development of testis, epididymis and accessory sex glands. [source] Toxicity of oral exposure to 2,4,6-trinitrotoluene in the western fence lizard (Sceloporus occidentalis),ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2008Craig A. McFarland Abstract Contamination of the soil with the explosive 2,4,6-trinitrotoluene (TNT) has been found at military sites, many of which are habitats used by reptiles. To provide data useful in assessing ecological risk for reptilian species, acute, subacute, and subchronic oral toxicity studies were conducted with the western fence lizard (Sceloporus occidentalis). Oral median lethal dose (LD50) values for TNT in corn oil were 1,038 and 1,579 mg/kg of body weight for male and female lizards, respectively. Overt signs of toxicity included chromaturia, abdominal enlargement, and tremors. A 14-d subacute study followed in which male lizards were orally dosed with TNT (corn oil) at 0, 33, 66, 132, 263, 525, and 1,050 mg/kg of body weight each day. Clinical signs of toxicity, while similar to the LD50 study, were more subtle and noted in lizards receiving TNT amounts of at least 66 mg/kg/d. Chromaturia was an early consistent sign, often preceding the onset of adverse effects. Male lizards in the 60-d subchronic study were dosed at 0, 3, 15, 25, 35, and 45 mg/kg/d with nearly complete survival (>90%) for lizards in all treatments. Changes in food consumption and body weight were observed at 35 and 45 mg/kg/d. Alterations in hematological end points; blood chemistries (albumin, total protein, alkaline phosphatase, calcium); kidney, spleen, and liver weights; and adverse histopathology were observed in lizards exposed at 25 to 45 mg/kg/d. Testosterone concentration, sperm count, and motility were variable between treatments. Although not significant, incidences of hypospermia and testicular atrophy were observed in some individuals. Together, these data suggest a lowest-observed-adverse effect level of 25 mg/kg/d and a no-observed-adverse effect level of 15 mg/kg/d in S. occidentalis. [source] Parasites, testosterone and honest carotenoid-based signalling of healthFUNCTIONAL ECOLOGY, Issue 5 2007F. MOUGEOT Summary 1Among the commonest sexual signals of birds are the red-yellow traits pigmented by carotenoids, but how they reliably advertise individual quality remain poorly understood. Here we tested the hypothesis that carotenoid-based signalling is enhanced by testosterone but reduced by parasites, and that the dual action of testosterone on ornament expression and parasite resistance ensures reliable signalling. 2Tetraonid birds such as the red grouse Lagopus lagopus scoticus have bright red combs pigmented by carotenoids, which function in intra- and inter-sexual selection. In separate experiments, we manipulated a main nematode parasite, Trichostrongylus tenuis (using deparasitation and re-infection) and testosterone (using testosterone or combined Flutamide/ATD treatments) in free-living males and investigated effects on plasma carotenoids and comb colour. 3In untreated males, comb redness positively correlated with plasma carotenoids, testosterone concentration and condition. Plasma carotenoids and comb redness both negatively correlated with T. tenuis abundance. 4Plasma carotenoids decreased in response to a challenge from T. tenuis, but increased when parasites were reduced. Testosterone enhanced comb redness, but tended to deplete plasma carotenoids. Combined Flutamide and ATD treatment had no significant effects on comb colour or plasma carotenoids, indicating that testosterone effects might be direct. 5Our experiments show contrasted effects of testosterone and nematode parasites on carotenoid-based ornamentation. Testosterone and parasites have well documented interactions in the study model. These, together with the opposite effects that testosterone and parasites have on carotenoid availability and use, would shape optimal levels of signalling, depending on individual quality, and might ensure reliable signalling. 6Carotenoid-based and testosterone-dependent traits have rarely been linked. Our study provides such a connection and shows that investigating how parasites, testosterone and carotenoids interact helps in the understanding of the evolution and maintenance of honest carotenoid-based signals of health. [source] The effect of sexual hormone abnormalities on proximal femur bone mineral density in hemodialysis patients and the possible role of RANKLHEMODIALYSIS INTERNATIONAL, Issue 1 2008Konstantinos K. DOUMOUCHTSIS Abstract Sexual hormone concentrations are commonly affected in chronic renal failure. The contribution of sex steroids to bone turnover regulation implies that sex steroid's dysfunction may be implicated in the emergence of renal osteodystrophy. This study was conducted to evaluate sex steroids and gonadotrophins in hemodialysis (HD) patients and to investigate their role in bone homeostasis in concert with other hormones and cytokines. Bone mineral density (BMD) at the proximal femur and intact parathyroid hormone (iPTH), osteoprotegerin, soluble receptor activator of NF-,B ligand (sRANKL), prolactin, total testosterone, estradiol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured in serum samples in 42 patients, 21 men and 21 women, on maintenance HD therapy. Possible associations between clinical characteristics, biochemical parameters, and BMD values were investigated. In male HD patients, the testosterone concentration declined significantly with aging, whereas the estradiol level increased with longer duration of HD. Concurrently, testosterone correlated negatively with sRANKL concentrations (r=,0.520, p=0.016). Luteinizing hormone levels in male patients demonstrated statistically significant negative correlations with BMD values of the proximal femur. In the entire cohort of patients, FSH and LH were negatively associated with absolute values of proximal femur BMD. Gonadotrophin and sexual hormone concentrations in HD patients are associated with bone mineral status and consequently their derangements appear to contribute to the development of bone composition abnormalities in different types of renal osteodystrophy. Furthermore, testosterone's association with sRANKL levels in male HD patients suggests that RANKL may mediate the effect of testosterone on bone metabolism in these patients. [source] Association Between Testosterone and Estradiol and Age-Related Decline in Physical Function in a Diverse Sample of MenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2008Andre B. Araujo PhD OBJECTIVES: To examine the association between aging and physical function in men by testing a theoretically based model of aging, hormones, body composition, strength, and physical function with data obtained from men enrolled in the Boston Area Community Health/Bone (BACH/Bone) Survey. DESIGN: Cross-sectional, observational survey. SETTING: Population-based. PARTICIPANTS: Eight hundred ten black, Hispanic, and white randomly selected men from the Boston area aged 30 to 79. MEASUREMENTS: Testosterone, estradiol, sex hormone,binding globulin, lean and fat mass, grip strength, and summated index of physical function (derived from walk and chair stand tests). RESULTS: Measures of grip strength and physical function declined strongly with age. For instance, 10 years of aging was associated with a 0.49-point difference (scale 0,7) in physical function. Age differences in total testosterone and estradiol concentrations were smaller than age differences in their free fractions. Weak or nonsignificant age-adjusted correlations were observed between hormones and measures of physical function, although path analysis revealed a positive association between testosterone and appendicular lean mass and a strong negative association between testosterone and total fat mass. Lean and fat mass, in turn, were strongly associated with grip strength and physical function, indicating the possibility that testosterone influences physical function via indirect associations with body composition. CONCLUSION: The age-related decline in serum testosterone concentration in men has a weak association with physical strength and functional outcomes through its associations with lean and fat mass. [source] Hypothalamic Expression of Human Growth Hormone Induces Post-Pubertal Hypergonadotrophism in Male Transgenic Growth Retarded RatsJOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2006J. S. Davies Growth hormone (GH) is known to regulate peripheral components of the hypothalamo-pituitary gonadal (HPG) axis, but it remains unclear whether GH exerts a significant influence on the activity of the hypothalamo-pituitary components of the HPG axis. In this study, we investigated the development of HPG axis function in the male transgenic growth retarded (Tgr) rat, a model of moderate systemic GH deficiency caused by hypothalamic expression of human (h)GH. Impaired postnatal somatotroph expansion and moderate GH deficiency in male Tgr rats were accompanied by a two- to three-fold increase in pituitary gonadotrophin content, but without a significant change in the pituitary gonadotroph population. A three- to nine-fold elevation in basal circulating luteinising hormone concentration was seen in postpubertal Tgr rats, with a smaller increase in follicle-stimulating hormone. Despite this hypergonadotrophism, there was no corresponding increase in steroidogenic (circulating testosterone and seminal vesicle weights) or gametogenic (spermatozoa counts in seminiferous tubules) activity in the postpubertal Tgr testis. Following puberty, the plasma leptin concentration also became progressively elevated in Tgr males. Circulating gonadotrophin and leptin levels were normalised in Tgr rats by peripheral physiological replacement of rat GH, but plasma testosterone concentration was unaffected. These results confirm that hGH exerts a positive influence on the central control of gonadotrophin secretion in the Tgr rat, but the absence of a corresponding elevation in the steroidogenic or gametogenic function of the Tgr testis implies that the peripheral GH/insulin-like growth factor I axis may also exert a permissive influence on testicular function. The relative contribution of somatogenic and lactogenic mechanisms and the potential influence of elevated leptin and decreased sensitivity to androgen feedback to the development of postpubertal hypergonadotrophism in Tgr males remain to be determined. [source] Moderate Seasonality in Testis Function of Domestic CatREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2007S Blottner Contents Adult male domestic cats are known to produce sperm throughout the year, although sexual activity is influenced by geographical location. In the northern hemisphere, feral domestic cats reproduce usually between January and July. Thus, seasonality in testicular activity might be suggested. The aim of the present study was to investigate gametogene and endocrine activity of cat testis throughout the entire year. Testes and epididymides (n = 10,12 per month) were collected after castration. Spermatogenesis was quantified by assessment of testicular sperm per testis and by flow cytometric analysis of the cells with different DNA content. Sperm from cauda epididymis were evaluated according to motility and morphological integrity. Testicular testosterone concentration was determined by enzyme immunoassay. Testis mass and sperm production varied moderately throughout the year. Significant seasonal variations were observed in the proportion of cells in the G2/M phase of cell cycle (p = 0.004) and the meiotic transformation (ratio of haploid : tetraploid cells; p = 0.021). Changes in testicular testosterone concentration were more pronounced and showed periods with high (spring) and significantly reduced testosterone levels (autumn). A marked seasonal alteration (p < 0.001) with a peak in March was assessed in the percentage of progressively motile sperm. The proportion of morphological intact sperm was also significantly higher in spring compared with winter time (p < 0.001). In conclusion, the study suggests moderate seasonal changes in quantity of sperm, more pronounced annual variation in hormone production and a distinct seasonal influence on functional sperm parameters in domestic cat. [source] Effect of growth hormone on testicular dysfunction induced by methotrexate in ratsANDROLOGIA, Issue 2 2009H. Serati Nouri Summary Methotrexate (MTX) is a chemotherapeutic agent causing defective oogenesis and spermatogenesis. This study was performed to assess the role of human growth hormone (GH) on testis recovery after treatment with MTX. Forty male Wistar rats were selected and randomly divided into four groups (n = 10): control (vehicle), GH group (0.3 mg kg,1 GH for 28 days, IP), MTX group (MTX 1 mg kg,1 week,1 for 4 weeks, IP) and GH/MTX group (0.3 mg kg,1 GH for 28 day plus 1 mg kg,1 week,1 MTX for 4 weeks, IP). On days 14 and 28, five rats from each group were killed, testes of rats of all groups were removed, spermatozoa were collected from epididymis and then prepared for analysis. MTX caused significant increase in interstitial tissue and capsular thickness and decrease of testicular and body weight (P < 0.05). Moreover, it caused significant decline in seminiferous tubule diameter and epithelium thickness (P < 0.05). There was no obvious change in morphometrical parameters between MTX/GH and control groups. In MTX group, sperm parameters decreased significantly (P < 0.05). Administration of GH plus MTX reduced the effects of MTX on sperm parameters and testosterone concentration. These results suggested that GH had a protective effect on almost all destructive effects caused by MTX in rat testes and thus improved sperm parameters. [source] Predictors of improved seminal characteristics by varicocele repairANDROLOGIA, Issue 1 2009Y. Kondo Summary The aim of this study was to investigate predictors of the improvement of semen characteristics after low ligation for patients with varicoceles. The records of 97 oligozoospermic patients who underwent microsurgical left or bilateral inguinal varicocele repair were retrospectively evaluated. We assessed factors that could be predictors of the improvement of semen characteristics using logistic regression analysis. We evaluated age, testicular volume, varicocele grade, serum follicle-stimulating hormone (FSH), luteinising hormone, testosterone, sperm concentration and motility before low ligation. Among the 97 patients, sperm concentration improved from 6.4 ± 5.8 to 24.2 ± 35.1 million ml,1 and sperm motility increased from 32.8 ± 24.9% to 41.0 ± 14.6% in 55 patients (57%). In logistic regression analysis, pre-operative serum FSH and testosterone concentration were predictors of sperm concentration improvement. Varicocele repair improved sperm concentration and motility. Low serum FSH and high testosterone are significant factors predicting the improvement of semen characteristics before low ligation. [source] Role of endogenous testosterone concentration in pediatric stroke,ANNALS OF NEUROLOGY, Issue 6 2009Sandra Normann MD Previous studies have indicated a male predominance in pediatric stroke. To elucidate this gender disparity, total testosterone concentration was measured in children with arterial ischemic stroke (AIS; n = 72), children with cerebral sinovenous thrombosis (CSVT; n = 52), and 109 healthy controls. Testosterone levels above the 90th percentile for age and gender were documented in 10 children with AIS (13.9%) and 10 with CSVT (19.2%), totaling 16.7% of patients with cerebral thromboembolism overall, as compared with only 2 of 109 controls (1.8%; p = 0.002). In multivariate analysis with adjustment for total cholesterol level, hematocrit, and pubertal status, elevated testosterone was independently associated with increased disease risk (odds ratio [95% confidence interval]: overall = 3.98 [1.38,11.45]; AIS = 3.88 [1.13,13.35]; CSVT = 5.50 [1.65,18.32]). Further adjusted analyses revealed that, for each 1nmol/l increase in testosterone in boys, the odds of cerebral thromboembolism were increased 1.3-fold. Ann Neurol 2009;66:754,758 [source] Using a GnRH agonist to obtain an index of testosterone secretory capacity in the cockatiel (Nymphicus hollandicus) and sulphur-crested cockatoo (Cacatua galerita)AUSTRALIAN VETERINARY JOURNAL, Issue 1-2 2010EM Lovas Objective Validation of a stimulation test for determining the steroidogenic capacity of the parrot testis. The major aim was to characterise testosterone secretion after injection of a gonadotropin-releasing hormone agonist (GnRHa), then use the test to investigate seasonal reproduction in the male cockatiel. Procedure A synthetic GnRHa (buserelin; 8.0 µg of peptide/kg bodyweight) was injected IM into male cockatiels (n = 7) and sulphur-crested cockatoos (n = 3) and serial blood samples collected at 0, 30, 60, 90 and 120 min after administration. Once validated, the technique was subsequently used to examine seasonal changes (23 months) in the testosterone profile of a captive cockatiel population. Results Injection of buserelin resulted in a significant increase in the testosterone concentration of cockatiel plasma, with maximal concentrations occurring at approximately 60 (1.33 ± 0.08 ng/mL) to 90 min (1.22 ± 0.08 ng/mL) after injection. Although no clear pattern of seasonal variation in testosterone secretion was detected in cockatiel plasma, samples taken 60 and 90 min after administration showed a significant increase in all seasons. Injection of buserelin in the sulphur-crested cockatoo also resulted in increased testosterone secretion, with maximal concentrations obtained after 90 min. Conclusion Buserelin can be used to obtain a reliable index of the prevailing testosterone capacity of the cockatiel and cockatoo testis. With further studies, this test may be incorporated into clinical assessment of reproductive status. [source] ,What should I do with a 60-year old man with a slightly low serum total testosterone concentration and normal levels of serum gonadotrophins'?CLINICAL ENDOCRINOLOGY, Issue 5 2010T. Hugh Jones Summary The fundamental question in assessing an older man with a slightly low total testosterone and normal gonadotrophin levels is to determine whether or not he has clinical hypogonadism. Hypogonadism is defined as a clinical syndrome complex, which comprises both symptoms as well as biochemical testosterone deficiency. As symptoms are nonspecific and there are no clear cut-off values for testosterone levels this invariably leads to a clinical dilemma. International guidelines have been published which provide recommendations to aid the clinician in making a diagnosis. Late-onset hypogonadism, the preferred terminology for age-related hypogonadism, can only be made once other causes have been excluded. Evidence shows that low testosterone levels are associated with several common male conditions including erectile dysfunction, osteoporosis and diabetes. Short-term studies have shown benefits of testosterone replacement therapy (TRT) on body composition, bone metabolism, insulin resistance, sexual function and quality of life. Recommendations give clear advice on safety monitoring, specifically in relation to prostate health. If a diagnosis of hypogonadism is made with borderline testosterone levels then a 3-month trial of TRT can be considered. The diagnosis of hypogonadism associated with borderline testosterone levels and the decision to treat should only be made by an experienced clinician. [source] Measurement of testosterone in the diagnosis of hypogonadism in the ageing maleCLINICAL ENDOCRINOLOGY, Issue 4 2008M. J. Wheeler Summary Many males in their old age demonstrate symptoms consistent with hypogonadism. With the introduction of new and more convenient methods of testosterone replacement treatment of these males is more practical. The diagnosis of hypogonadism in the older male has been controversial with some clinicians suggesting that symptoms should be treated without due reliance on testosterone concentrations. However, most professional bodies have proposed that a low testosterone concentration should be part of the diagnosis. This is, in turn, reliant on the testosterone measurement being reliable and read against an appropriate reference range. This review looks at the factors that can influence the interpretation of testosterone results for the ageing male. [source] Evaluation of the methoxytriazine herbicide prometon using a short-term fathead minnow reproduction test and a suite of in vitro bioassaysENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2006Daniel L. Villeneuve Abstract Prometon is one of the most consistently detected herbicides in the U.S. environment. However, no previous assessment of the potential for prometon or related methoxytriazine herbicides to act as endocrine-disrupting chemicals has been conducted. This study used an array of in vitro bioassays to assess whether prometon, atraton, terbumeton, or secbumeton might act as potent (ant)agonists of the aryl hydrocarbon, estrogen, androgen, or glucocorticoid receptors or as aromatase inhibitors or inducers in vitro. Potential effects of prometon were also evaluated using a 21-d fathead minnow reproduction assay. Concentrations of methoxytriazines, as great as 1 mg/L (4.4 ,M), did not induce significant dioxin-like responses in H4IIE-luc cells, estrogenic responses in MVLN cells, or androgen or glucocorticoid receptor,mediated responses in MDA-kb2 cells, nor did the methoxytriazines significantly affect aromatase activity in vitro. In the fathead minnow assay, exposure to 20, 200, or 1,000 ,g prometon/L significantly reduced the weight of the male fat pad (an androgen-responsive tissue) relative to body weight. Exposure to 20 ,g prometon/L significantly increased female plasma testosterone concentrations, but the effect was not observed at greater concentrations. Overall, prometon did not significantly reduce fecundity over the 21-d exposure, nor were other endpoints, including plasma vitellogenin and estradiol concentrations, brain and ovary aromatase activity, and male tubercle index, significantly affected. Evidence from our work suggests that prometon may cause subtle endocrine and/or reproductive effects in fathead minnows, but no clear mechanism of action was observed. The relevance of these effects to hazard assessment for the pesticide is uncertain. [source] Androgen receptor gene polymorphism and the metabolic syndrome in 60,80 years old Norwegian menINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2010Paal André Skjærpe Summary The metabolic syndrome (MS) includes a clustering of metabolic derangements. Low testosterone levels have been shown to be associated with both components of MS and MS per se. As most androgen-related effects are mediated thorough the androgen receptor (AR), we wanted to investigate to which degree the AR CAG and GGN repeat polymorphisms might be related to MS. Sixty-eight men, 60,80 years old, with subnormal total testosterone levels (,11.0 nmol/L) and 104 men with normal levels (>11.0 nmol/L), participating in a nested case,control study were investigated in this study. Body weight, height, waist circumferences and blood pressure were measured. Fasting blood samples were drawn and an oral glucose tolerance test (OGTT) was performed. The CAG and GGN polymorphisms in the AR gene were determined by direct sequencing of leucocyte DNA. Men with MS had lower CAG repeat number than healthy men (p = 0.007). There were, however, no difference in CAG or GGN repeats length between the groups with subnormal or normal testosterone concentrations. In cross-sectional analyses, men with CAG repeat lengths , 21 had significantly higher fasting glucose, C-peptide and glycosylated haemoglobin (HbA1c) levels (all p < 0.05). In multiple regression analyses, CAG repeat length was an inverse and independent predictor of glucose after an OGTT and of HbA1c levels. We also found that men with more than one component of MS had shorter CAG repeat number (p for trend 0.013) than those with only one component. In conclusion, there were no associations with GGN repeat length, while short CAG repeat length seems to be associated with increased risk of MS. [source] StriantÔ SR: a novel, effective and convenient testosterone therapy for male hypogonadismINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 11 2004M. Korbonits Summary StriantÔ SR (marketed as Striant® in the US) is a novel sustained-release mucoadhesive buccal testosterone tablet for the treatment of male hypogonadism. StriantÔ SR restores serum testosterone concentrations to the physiological range within 4 h of application, and steady-state concentrations are achieved within 24 h of twice-daily dosing. In phase III clinical trials, 87,97% of patients using StriantÔ SR achieved 24-h-averaged serum testosterone concentrations within the normal range. In a comparative study, StriantÔ SR was more likely to restore testosterone concentrations to the physiological range than Andropatch®. In a small study, StriantÔ SR produced steady-state testosterone concentrations comparable with those achieved with a testosterone gel (50 mg testosterone). StriantÔ SR was well tolerated, with a low incidence of adverse events and a low discontinuation rate (3.5%) due to adverse events in phase III studies. StriantÔ SR is an effective, well-tolerated, convenient and discreet treatment for male hypogonadism. [source] Prostate cancer in patients with Hansen's diseaseINTERNATIONAL JOURNAL OF UROLOGY, Issue 3 2003Isao Kiriyama Abstract Hansen's disease causes testicular failure secondarily, and because of this, it has been considered that prostate cancer would not be found in association. Three of 14 patients with chronic leprosy in Suruga National Sanatorium Hansen's Disease Hospital were found to have prostate cancer. A 72-year-old with lepromatous leprosy was diagnosed with stage T3a prostate cancer and treated with radical prostatectomy after hormonal therapy, plus irradiation. An 80-year-old with lepromatous leprosy was diagnosed with stage T2 prostate cancer and treated with irradiation and follow up only without hormone therapy and surgery because of his low testosterone level and old age. An 82-year-old with borderline leprosy was diagnosed with stage T1c prostate cancer and because of the pathological finding of low Gleason score and his old age, he was treated with hormonal therapy only. Two of the three cases had elevated concentrations of follicle-stimulating hormone and luteinizing hormone, which suggests that their prostatic cancers might have been equivalent to be under the influence of hormone therapy. Therefore, in aged male patients with Hansen's disease, the follicle-stimulating hormone, luteinizing hormone and testosterone concentrations should be measured, as well as that of prostate-specific antigen, and a prostate biopsy should be also considered if the prostate-specific antigen concentration is increased, even with hypogonadism. [source] Changes in Muscle Mass, Muscle Strength, and Power but Not Physical Function Are Related to Testosterone Dose in Healthy Older MenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2008Thomas W. Storer PhD OBJECTIVES: To examine the effect of graded doses of testosterone on physical function and muscle performance in healthy, older men. DESIGN: Randomized, double-blind, placebo-controlled clinical trial. SETTING: General clinical research center. PARTICIPANTS: Community-dwelling healthy men aged 60 to 75 (N=44). INTERVENTION: Monthly treatment with a gonadotropin-releasing hormone agonist plus 25, 50, 125, or 300 mg/wk of intramuscular injections of testosterone enanthate for 20 weeks. MEASUREMENTS: Skeletal muscle mass (SMM) was estimated using dual-energy X-ray absorptiometry. Leg press strength was measured by one repetition maximum, leg power by Nottingham Leg Rig, and muscle fatigability by repetitions to failure in the leg press exercise. Stair climbing, 6-meter and 400-meter walking speed, and a timed-up-and-go (TUG) test were used to assess physical function. RESULTS: Significant testosterone dose- and concentration-dependent increases were observed in SMM (P<.001) and maximal strength (P=.001) but not muscle fatigability. Leg power also increased dose-dependently (P=.048). In contrast, changes in self-selected normal and fast walking speed over 6 or 400 meters, stair climbing power, and time for the TUG were not significantly related to testosterone dose, testosterone concentrations, or changes in muscle strength or power, or SMM. CONCLUSION: Testosterone administration was associated with dose-dependent increases in SMM, leg strength, and power but did not improve muscle fatigability or physical function. The observation that physical function scores did not improve linearly with strength suggests that these high-functioning older men were already in the asymptotic region of the curve describing the relationship between physical function and strength. [source] Multiple pathways of maternal effects in black-headed gull eggs: constraint and adaptive compensatory adjustmentJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2006T. G. G. GROOTHUIS Abstract We investigated in the black-headed gull whether female deposition of antioxidants and immunoglobulins (enhancing early immune function), and testosterone (suppressing immune function and increasing early competitive skills) correlate suggesting that evolution has favoured the mutual adjustment of different pathways for maternal effects. We also took egg mass, the position of the egg in the laying sequence and offspring sex into account, as these affect offspring survival. Yolk antioxidant and immunoglobulin concentrations decreased across the laying order, while yolk testosterone concentrations increased. This may substantially handicap the immune defence of last-hatched chicks. The decrease in antioxidant levels was greater when mothers had a low body mass and when the increase in testosterone concentrations was relatively large. This suggests that female black-headed gulls are constrained in the deposition of antioxidants in last-laid eggs and compensate for this by enhanced testosterone deposition. The latter may be adaptive since it re-allocates the chick's investment from costly immune function to growth and competitive skills, necessary to overcome the consequences of hatching late from an egg of reduced quality. [source] Using the composite variables of reproductive morphology, histology and steroid hormones to determine age and size at sexual maturity for the thorny skate Amblyraja radiata in the western Gulf of MaineJOURNAL OF FISH BIOLOGY, Issue 5 2006J. A. Sulikowski Age at size was linked to sexual maturity in 77 male and 93 female thorny skates Amblyraja radiata from the western Gulf of Maine using three criteria: 1) gross reproductive morphology, 2) histology and 3) steroid hormone concentrations. Age-bias plots and the coefficient of variation from vertebral band counts suggested that the ageing method represented a non-biased and precise approach to the age assessment of A. radiata. Maturity ogives for males, based on data gathered for clasper length, circulating testosterone concentrations and proportion of mature spermatocysts within the testes, predicted that 50% maturity occurred at a total length (LT) of 865 mm and c. 10·90 years of age. For females, maturity ogives, based on data gathered for ovary mass, shell gland mass, follicle size and circulating oestradiol concentrations, predicted that 50% maturity occurred at 875 mm LT and c. 11·00 years of age. Collectively, the results suggest that analysis of several contemporaneous reproductive variables offers an accurate determination of sexual maturity in the thorny skate. [source] A 5-year follow-up study of disease incidence in men with an abnormal hormone patternJOURNAL OF INTERNAL MEDICINE, Issue 4 2003R. Rosmond Abstract Rosmond R, Wallerius S, Wanger P, Martin L, Holm G, Björntorp P (The Cardiovascular Institute, Sahlgrenska University Hospital, Göteborg; and Huddinge University Hospital, Huddinge; Sweden). A 5-year follow-up study of disease incidence in men with an abnormal hormone pattern. J Intern Med 2003; 254: 386,390. Objectives. Previous studies have suggested that abnormal levels of cortisol and testosterone might increase the risk of serious somatic diseases. To test this hypothesis, we conducted a 5-year follow-up study in middle-aged men. Methods. A population-based cohort study conducted in 1995 amongst 141 Swedish men born in 1944, in whom a clinical examination supplemented by medical history aimed to disclose the presence of cardiovascular disease (CVD) (myocardial infarction, angina pectoris, stroke), type 2 diabetes and hypertension were performed at baseline and at follow-up in the year 2000. In addition, salivary cortisol levels were measured repeatedly over the day. Serum testosterone concentrations were also determined. Using the baseline data, an algorithm was constructed, which classified the secretion pattern of cortisol and testosterone from each individual as being normal or abnormal. Results. By the end of follow-up, men with an abnormal hormone secretion pattern (n = 73) had elevated mean arterial pressure (P = 0.003), fasting insulin (P = 0.009) and insulin : glucose ratio (P = 0.005) compared with men with a normal secretion pattern (n = 68). Body mass index, waist circumference, and waist : hip ratio were significantly elevated in both groups. However, the 5-year incidence of CVD, type 2 diabetes, and hypertension were significantly higher (P < 0.001) in men with an abnormal neuroendocrine secretory pattern compared to men with a normal pattern. Conclusions. These data suggest that an abnormal neuroendocrine secretory pattern is prospectively associated with an increased incidence of cardiovascular-related events and type 2 diabetes. [source] Reproductive seasonality in the Tete veld rat (Aethomys ineptus) (Rodentia: Muridae) from southern AfricaJOURNAL OF ZOOLOGY, Issue 2 2006S. P. Muteka Abstract Very little is known about the reproductive biology of the recently recognized Tete veld rat Aethomys ineptus. In the present study, we investigated the seasonality of reproduction in this newly recognized rodent using a number of histological and endocrinological parameters. Body mass, reproductive tract morphometrics, gonadal histology, and plasma testosterone concentrations in males and plasma oestradiol-17, and progesterone concentrations in females were assessed from a population in the north-central part of South Africa over a 12-month period in order to ascertain the pattern of reproduction in the species. Seminiferous tubule diameters in 59 males were significantly larger between September and February relative to between March and August. Although spermatogenesis was prevalent in the southern hemisphere winter (June,August), the number of spermatozoa in the epididymides decreased in the southern hemisphere spring (September,November), summer (December,February) and autumn (March,May). Testicular mass relative to body mass and testicular volume regressed between May and September but exhibited recrudescence between September and April, whereas plasma testosterone concentrations increased significantly between September and February relative to between March and August. Ovarian histology of 67 females showed corpora lutea to be present throughout the year, but decreased in number during winter, whereas mean plasma progesterone concentration increased significantly between August and November and again between February and April. This bimodal pattern of progesterone concentration suggests that up to two litters per breeding season may be raised by the Tete veld rat. Gravid females were found between October and April, whereas gravid or lactating females were conspicuously absent between May and September. Collation of all these data suggests that the Tete veld rat is a seasonal breeder with reproduction confined predominantly to summer and autumn months of the southern hemisphere. However, the presence of follicular development in females and the presence of corpora lutea outside the breeding season imply that the Tete veld rat may undergo spontaneous ovulation. [source] The odour of pyrazine increases the egg mass of domestic chickens (Gallus gallus domesticus L.)JOURNAL OF ZOOLOGY, Issue 3 2002Anat Barnea Abstract Forty leghorn chickens at the commencement of egg laying, were divided into two groups, each with 10 females and 10 males. One group was exposed to the odour of synthetic pyrazine (2-methoxy-3-isobutylpyrazine) for 16 weeks while the other acted as a control. During the first 4 weeks the hens exposed to pyrazine odour laid significantly fewer eggs (unfertilized) than the controls, but thereafter both groups laid a similar number. Mean egg mass of the pyrazine exposed hens was significantly (P= 0.012) greater (5.5%) than that of the control group. No significant difference was found in body mass or eggshell thickness. Similarly, there were no consistent significant differences between groups in oestrogen and testosterone concentrations in the blood of females and males, respectively. No pyrazine could be detected in cloacal extracts. The experiment shows that an external odour can affect the internal reproductive system of the chicken. It is suggested that the pyrazine-engendered increase in egg mass involves neuroendocrine regulation within the hypothalamus rather than hormonal interactions ,downstream' of the brain. [source] No place like home: Testosterone responses to victory depend on game locationAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2009Justin M. Carré Several studies have demonstrated that a variety of factors influence testosterone responses to competitive interactions. This study examined the extent to which game location would influence testosterone responses to human competition. Male amateur ice hockey players (n = 10) provided saliva samples before and after competing against the same opponent on two separate occasions (one game at home and one game away). Although both games resulted in similar victories, the home victory was associated with a significantly larger rise in testosterone concentrations relative to the away victory. The factors responsible for the different testosterone responses are not known, however, it is possible that a rise in status in front of the home crowd is more rewarding to athletes, and thus, a more potent stimulus for the endocrine system. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source] Reproductive Development of Santa Inês Rams During the First Year of Life: Body and Testis Growth, Testosterone Concentrations, Sperm Parameters, Age at Puberty and Seminal Plasma ProteinsREPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2010CEA Souza Contents We have investigated the reproductive development of the tropically adapted Santa Inês ram, the most common hair sheep in Brazil. From 8 to 48 weeks of age, 16 animals were evaluated for body and testis growth, semen parameters, testosterone concentrations and seminal plasma proteins, using two-dimensional SDS-PAGE. Animals were weaned at 30 days and kept in feedlots thereafter, receiving hay, concentrate (18% of crude protein) and mineral supplement. Body weight increased from 12.3 ± 0.7 to 54.3 ± 1.6 kg between 8 and 48 weeks (p < 0.05), but changes in thoracic perimeter and scrotal circumference were non-significant after 36 weeks (p > 0.05). The percentage of motile sperm increased slowly until 23 weeks and more rapidly after that age, but significant changes in progressive motility occurred after 25 weeks. Presence of abnormal sperm related inversely to age. Most significant changes in sperm concentration occurred between 38 and 44 weeks (0.38 ± 0.05 to 1.14 ± 0.24 × 109 cells/ml, p < 0.05) and testosterone reached its highest concentrations at 42 weeks, decreasing afterwards. Rams reached puberty at 28.2 ± 0.8 weeks. The number of protein spots on seminal plasma gels was similar from 15 to 18 weeks (45 and 47 spots; p > 0.05), increased until 24 weeks (141 spots) and 28 weeks (170 spots; p < 0.05) and remained without significant (p > 0.05) changes from 28 to 48 weeks (186 ± 10 spots). Furthermore, the intensity of selected spots on 2D maps increased (p < 0.05) between 15 and 28 weeks, which preceded or coincided with the main developmental changes in sperm motility and percentage of defective sperm in the ejaculates. These results will support future studies designed to characterize specific seminal plasma proteins whose expression relate to the development of testis, epididymis and accessory sex glands. [source] Effects of Short-term Hyper- and Hypoprolactinaemia on Hormones of the Pituitary, Gonad and -Thyroid Axis and on Semen Quality in Male BeaglesREPRODUCTION IN DOMESTIC ANIMALS, Issue 2009MB Koivisto Contents Effects of a short-term hyper- and hypoprolactinaemia on serum concentrations of LH, testosterone and semen quality in six male Beagles were investigated. Blood samples were collected at 3-day intervals for 12 weeks. The time span was divided into five 3-week periods: pre-treatment, metoclopramide (MCP) treatment (0.2 mg/kg orally three times daily), cabergoline (CAB) treatment (5 ,g/kg orally once daily), post-treatment 1 and post-treatment 2. In the latter, only semen characteristics were evaluated. Semen parameters were analyzed once per week during the whole 15-week investigation time. At the end of each period, the effects of a single intravenous injection of thyrotropin-releasing hormone (TRH; 10 ,g/kg) on the secretion of prolactin (PRL), LH, testosterone, thyroid-stimulating hormone and thyroxine (T4) were investigated. Pre-treatment serum PRL concentration increased under MCP (p < 0.05), followed by a decrease under CAB administration (p < 0.05). Luteinizing hormone and testosterone concentrations were not affected. Except for straight-line sperm velocity, semen quality did not differ between collection periods. A single iv TRH injection induced a significant PRL increase at 20 min in all experimental periods except during CAB treatment. Luteinizing hormone and testosterone did not show clear TRH-related changes. Basic T4 levels were significantly reduced after CAB treatment (p < 0.05). The results of the present study demonstrate that MCP-induced short-term hyperprolactinaemia in male beagles does not seriously affect the hypothalamo-pituitary axis and semen quality. [source] Effects of Gonadotrophin Releasing Hormone Administration on the Pituitary-Ovarian Axis in Anoestrous vs Ovariectomized BitchesREPRODUCTION IN DOMESTIC ANIMALS, Issue 6 2006JJCWM Buijtels Contents The aim of this study was to determine the effects of gonadotrophin releasing hormone (GnRH) administration on the plasma concentrations of reproductive hormones in intact and ovariectomized (OVX) bitches. Therefore, blood samples were collected at multiple times before and after the administration of 10 ,g/kg GnRH (Fertagyl®) for the determination of the plasma concentrations of luteinizing hormone (LH), oestradiol, progesterone and testosterone in six anoestrus and in six OVX bitches. The mean plasma LH concentrations before and 60 min after GnRH administration were significantly lower in the anoestrous bitches than in the OVX bitches. In both groups GnRH administration resulted in a significant increase in the plasma LH concentration. The highest plasma LH concentrations were found at 10 min after GnRH administration and these values did not differ significantly between the two groups. Only in the anoestrous bitches a significant increase in plasma oestradiol concentrations was found after GnRH administration and these values were significantly higher than those in the OVX bitches. The plasma concentrations of progesterone and testosterone were low (close to or below the limit of quantitation) both before and after GnRH administration and the differences between anoestrous and OVX bitches were not significant. It can be concluded that (i) basal plasma LH concentration is significantly higher in OVX bitches than in anoestrous bitches, (ii) plasma LH concentration increases after GnRH administration in both anoestrous and OVX bitches, (iii) GnRH administration causes a significant rise in plasma oestradiol concentration only if ovarian tissue is present and (iv) measurement of plasma progesterone and testosterone concentrations before and after GnRH administration does not aid in distinguishing between anoestrous and OVX bitches. The results of this study may provide a basis for the diagnosis of remnant ovarian tissue and verification of neuter status in the bitch. [source] Short periods of prenatal stress affect growth, behaviour and hypothalamo,pituitary,adrenal axis activity in male guinea pig offspringTHE JOURNAL OF PHYSIOLOGY, Issue 3 2005Amita Kapoor Prenatal stress can have profound long-term influences on physiological function throughout the course of life. We hypothesized that focused periods of moderate prenatal stress at discrete time points in late gestation have differential effects on hypothalamo,pituitary,adrenal (HPA) axis function in adult guinea pig offspring, and that changes in HPA axis function will be associated with modification of anxiety-related behaviour. Pregnant guinea pigs were exposed to a strobe light for 2 h on gestational days (GD) 50, 51, 52 (PS50) or 60, 61, 62 (PS60) (gestation length ,70 days). A control group was left undisturbed throughout pregnancy. Behaviour was assessed in male offspring on postnatal day (PND)25 and PND70 by measurement of ambulatory activity and thigmotaxis (wall-seeking behaviour) in a novel open field environment. Subsequent to behavioural testing, male offspring were cannulated (PND75) to evaluate basal and activated HPA axis function. Body weight was significantly decreased in adult PS50 and PS60 offspring and this effect was apparent soon after weaning. The brain-to-body-weight ratio was significantly increased in adult PS50 males. Basal plasma cortisol levels were elevated in PS50 male offspring throughout the 24 h sampling period compared with controls. In response to an ACTH challenge and to exposure to an acute stressor, PS60 male offspring exhibited elevated plasma cortisol responses. Plasma testosterone concentrations were strikingly decreased in PS50 offspring. Thigmotaxis in the novel environment was increased in PS50 male offspring at PND25 and PND70, suggesting increased anxiety in these animals. In conclusion, prenatal stress during critical windows of neuroendocrine development programs growth, HPA axis function, and stress-related behaviour in adult male guinea pig offspring. Further, the nature of the effect is dependant on the timing of the maternal stress during pregnancy. [source] Influence of ageing and some lifestyle factors on male gonadal function: a study in BulgariaANDROLOGIA, Issue 4 2007P. Kumanov Summary There are few systematic studies on the relationship between blood testosterone concentrations and the symptoms of androgen deficiency in ageing males. To assess the changes in sex hormone levels with age in relation with some lifestyle factors, the serum levels of total testosterone (TT), sex-hormone binding globulin (SHBG), luteinising hormone (LH) and follicle stimulating hormone (FSH) were measured in 33 men, age range 40,89 years. In addition, free testosterone (FT) and the free androgen index (FAI) were calculated. Seventeen healthy men under 40 years were involved as controls. The men over 40 years revealed significantly decreased TT, FT and FAI, and in the subgroup of men over 60 years, FSH and SHBG were significantly increased. Pearson's analysis showed that TT levels were significantly correlated with body mass index (BMI) (r = ,0.464, P < 0.01) and body weight (r = ,0.413, P < 0.05). SHBG levels were significantly correlated not only with age (r = +0.407, P < 0.05), but also with LH (r = +0.605, P < 0.001) and alcohol consumption (r = +0.382, P < 0.05). In conclusion, the TT, FT and FAI decreased in males over 40 years, but the alterations in hormone levels with age are more pronounced in men over 60 years. The important determinants of sex hormones are age, BMI and some lifestyle factors. [source] Low testosterone levels and unimpaired melatonin secretion in young males with metabolic syndromeANDROLOGIA, Issue 6 2006R. Robeva Summary The interrelations between testosterone, insulin and melatonin levels in males with metabolic syndrome (MS) are still not clarified, especially in young age groups. The aim of the present study was to compare the testosterone serum levels in young men with MS to those in healthy controls, and to determine the possible changes in their melatonin rhythm, as well as the relation between melatonin, insulin and lipid profile. Fasting insulin and testosterone concentrations were measured in 10 healthy nonobese and 10 MS patients. Blood samples for melatonin, insulin and luteinizing hormone (LH) were collected at 19.00, 03.00 and 11.00 hours. A significant difference was found between the testosterone levels in controls and patients. Luteinizing hormone levels in both groups were similar, however, higher night LH levels in MS patients were observed. No changes in the melatonin concentrations of the two groups were found. In conclusion, total testosterone levels were significantly lower in young men with MS compared with healthy age-matched controls. Mild hypoandrogenia in hyperinsulinaemic patients was not related with changes in their melatonin levels. No alterations in the endogenous melatonin rhythm of the MS patients were found. [source] | ||||||||||||||||||||||||||||