Search results for "testosterone"
showing 10 items of 420 documents
Psychomotor and Motor Speed in Power Athletes Self-Administering Testosterone and Anabolic Steroids
1988
Abstract The effect of self-administered testosterone and anabolic steroids on psychomotor and motor speed were studied among five top-level power athletes. The experiment included a 26-week intensive strength training period in association with the use of exogenous hormones and a 6-week follow-up after drug withdrawal. Six athletes not using exogenous hormones served as a control group. The results indicated a similar, and in most cases insignificant, improvement (0–10%) in performance in both groups in both the simple and more complicated motor and psychomotor tests. Only in maximal vertical speed related to body weight was there more improvement in the experimental group, from 122.2 to 1…
Quantitative Structure–Activity Relationship of the 4,5α-Dihydrotestosterone Steroid Family
2006
Predictive Quantitative Structure - Activity Relationship (QSAR) models of Anabolic/ Androgenic (A/A) activities for the 4,5a-dihydrotestosterone steroid family were obtained by means of multilinear regression using quantum and physicochemical Molecular Descriptors (MDs) as well as a genetic algorithm for the selection of the best subset of MDs. MDs included in our QSAR models allow the structural interpretation of the biological process, evidencing the main role of the shape of molecules, hydrophobicity, and electronic properties. Attempts were made to include lipophilicity (octanol-water partition coefficient) as well as electronic (lowest unoccupied molecular orbital properties and dipol…
CHANGES IN ALBINO RAT TESTICLE INTERSTITIAL CELLS AFTER PITUITARY STIMULATION IN VIVO WITH HeNe LASER
1995
Population I Leydig cells of the central part of the Albino rat testicle showed signs of increased but nonspecific activity in the entire series of experimental animals compared with sham irradiated controls (n = 30 in each group) after anterior pituitary stimulation with low incident energy levels of the HeNe laser at 632.8 nm with an incident power at the pituitary calculated as 2.75 ± 0.25 mW. The authors conclude that LLLT applied to the pituitary in the rat model at the parameters used in the present study may have an effect on testosterone production. Further quantitative and qualitative work is required to assess the significance of the increase in activity of type I Leydig cells and…
Comparison of soft tissue body composition in postmenopausal women with or without hormone replacement therapy considering the influence of reproduct…
2001
To examine long-term effects of at least 5 years' conventional hormone replacement therapy (HRT), reproductive history and lifestyle on fat mass and muscle mass in postmenopausal women.A cross-sectional retrospective approach was used, including 64 healthy women (56-69 years, mean age 63.4 years). Hormone users were compared with age-matched non-users with respect to (a) type of HRT used (oestrogen vs oestrogen plus gestagen vs no hormones), (b) categories of oestrogens used (oestradiol-based oestrogens vs conjugated equine oestrogens vs no oestrogens) and (c) categories of gestagens used (testosterone derivatives vs progesterone derivatives vs no gestagens). Data on hormone use, reproducti…
Biological, Psychological, and Physical Performance Variations in Football Players during the COVID-19 Lockdown: A Prospective Cohort Study
2022
This prospective cohort study aimed to evaluate whether COVID-19 lockdown caused biological, psychological, and/or physical performance variations in footballers. We compared the 2018/2019 and 2019/2020 seasons evaluating the plasma volume, hematological parameters, iron/ferritin, creatine kinase, vitamin D, cortisol, testosterone, and physiological state of players of the Italian football major league (Serie A). Measurements were performed before the preparatory period (T0), at the beginning (T1) and in the middle (T2) of the championship, and in March (T3) and at the end of season (T4). The results showed that in the 2019/2020 season affected by the lockdown, the weight, BMI, and fat mass…
Salivary Testosterone and Cortisol Responses to Cycle Ergometry in Basketball Players with Different Training Volume
2002
Abstract This study analyzes the degree to which different amounts of training during a 4-month period affects salivary testosterone (Tsal), salivary cortisol (Csal) responses, and changes in the salivary testosterone/cortisol ratio (Tsal/Csal ratio) following acute physical effort. Two professional basketball teams with similar fitness levels carried out a maximal cycle ergometry at the beginning and in the middle of the sports season. In both sessions, saliva samples were collected to determine Tsal and Csal, and mood was assessed. Training was registered daily, total training volume being almost two-fold higher in Team 1 than in Team 2. No significant differences between the teams in an…
Use of Saliva in Alternative to Serum Sampling to Monitor Biomarkers Modifications in Professional Soccer Players
2018
We aimed to investigate the correlation between serum and salivary concentrations of steroid hormones and IgA, and the variation in concentrations of these biomarkers, across a soccer competitive season in a sample of players playing for an Italian major League team. Thirty-five elite male soccer players were recruited and assessed for salivary hormones (cortisol, testosterone, T/C‰ and DHEA-S) and IgA at three different time-points: (t1) after the pre-season period and 16 official matches played; (t2) after a winter break and three official matches played; (t3) 2 days after the final match of the championship and 19 matches played. Players were also tested for blood biomarkers (ser-C, ser-…
Topical canrenoic acid. Quantification of the antiandrogenic activity in the hamster flank organ
1991
: The topical antiandrogenic activity of potassium canrenoate (CAK), compared with that of spironolactone (SP), was assayed in vivo in female golden Syrian hamsters whose flank organs were stimulated by subcutaneous administration of testosterone propionate. Sebaceous glands and hair were measured by a computerized image analyzer. Pigmented spots, sebaceous gland areas, and the diameter of hairs of the treated flank organs were smaller in the groups that received CAK (1·6 mg/day) and SP (0·4 mg/day). The authors' results showed that CAK may act as a topical antiandrogen on the hamster flank organ when applied in concentrations four times greater than the minimal active dosage of SP. Potassi…
Testosterone and attribution of successful competition
2000
Mood, personal merit, and/or its perception have been suggested to be mediating factors in testosterone responses to competition. Previously we have found that personal contribution and attribution were related to testosterone levels after successful competition. To confirm such associations, two basketball teams (n = 17 players) that emerged as winners in two actual matches were studied. Salivary testosterone levels and mood were measured before and after the games. Individual contribution to the outcome was assessed, and personal satisfaction and causal attribution of outcome were reported by players. Testosterone concentrations increased to near significance in Team 1 but not in Team 2, …
Effects of strength training on muscle power and serum hormones in middle-aged and older men.
2001
Effects of 16-wk strength training on maximal strength and power performance of the arm and leg muscles and serum concentrations [testosterone (T), free testosterone (FT), and cortisol] were examined in 11 middle-aged (M46; 46 ± 2 yr) and 11 older men (M64; 64 ± 2 yr). During the 16-wk training, the relative increases in maximal strength and muscle power output of the arm and leg muscles were significant in both groups ( P < 0.05–0.001), with no significant differences between the two groups. The absolute increases were higher ( P < 0.01–0.05) in M46 than in M64 mainly during the last 8 wk of training. No significant changes were observed for serum T and FT concentrations. Analysis o…