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1.
Nine rowers (six men of the regional and three women of the national top class) participated in the study. During 7 consecutive weeks of the competition period serum testosterone (T), SHBG, cortisol (C) and urea were determined at the same time every morning under fasting conditions. From the concentrations of T and SHBG the free testosterone fraction (T/SHBG) was calculated, and from the concentrations of T and C the ratio of T/C was derived. The object of the investigation was to gather information on a potentially altered anabolic-catabolic hormone relationship dependent upon the intensity of the individual training periods. All rowers showed a continuous decrease in T, T/SHBG and T/C during the observation period. A week of regenerative training halted the decrease. In two of the oarsmen who discontinued their training after 2 and 3 weeks respectively, T, T/SHBG and T/C showed a normalization in the following weeks. In all subjects the concentrations of urea increased during the first 2 weeks and decreased during the subsequent weeks of intense training and competition. The findings suggest an increase in catabolic activity in periods of intensive physical strain, including competitions. Regenerative phases of training seem to reduce the anabolic-catabolic imbalance.  相似文献   

2.
This study was performed on 16 professional racing cyclists to examine changes in urine concentrations of androgen hormones (testosterone, epitestosterone, androsterone, etiocholanolone, 11-hydroxy-androsterone and 11-hydroxy-etiocholanolone) and plasma sex hormone binding globulin (SHBG) after training and after competition. The urinary concentrations of androgen hormones decreased during the period of training and increased during competition, this being the reverse of what happened to SHBG plasma concentrations. These changes would suggest that physical activity may have an influence on the elimination of androgen hormones and on the synthesis of its transporting protein SHBG.  相似文献   

3.
Diurnal variations of serum sex hormone binding globulin (SHBG), testosterone (T) and estradiol (E2) in five normal adult men and five normal adult women were investigated. SHBG binding capacity was measured by both polyacrylamide gel electrophoresis and dextran-coated charcoal technique (DCC); T and E2 were assayed by RIA and free T and free E2 were determined by means of equilibrium dialysis. In male subjects the variations of SHBG binding capacity was associated with the changes of total T, free T and T/SHBG index, which had the highest concentrations in the morning and the lowest levels in the evening during the 24 h test period, but percentage free T remained unchanged. Serum protein concentrations did not change significantly during 24 h. No significant diurnal changes of SHBG binding capacity, total E2, free E2, percentage free E2 and percentage free T were found in female subjects in the mid-luteal phase of the menstrual cycle, although significant fluctuations of total T, free T and T/SHBG index were observed throughout the day. The results suggested that SHBG may play a buffer role in the presence of fluctuations of testosterone production during 24 h period, allowing stabilization of a bioactive fraction of the hormone both in normal adult male and female. However, the concentrations of T in normal adult women may be too low to drive any change of SHBG levels while there were no significant variations of E2 throughout a day in the mid-luteal phase of the menstrual cycle.  相似文献   

4.
AIMS: To compare the basal plasma reproductive hormonal profile in three groups of athletes involved in different training programs, and to define the relationship between androgen level and bone mineral density (BMD) in male athletes. METHODS: Basal serum total testosterone (TT), free androgen index (FAI), sex hormone-binding globulin (SHBG), cortisol, cortisol to TT ratio, luteinizing hormone (LH), estrogen and BMD were evaluated in cyclists (CY; n = 11), triathletes (TR; n = 14) and swimmers (SW; n = 13) and compared with less active controls (n = 10). RESULTS: TT and FAI levels were lower (p < 0.05) in CY and TR, whereas the ratio of cortisol to TT was increased in CY only (p < 0.05). No alteration in serum LH, SHBG, estrogen or cortisol concentration was observed. BMD was higher in the proximal femur in TR (p < 0.05). No BMD or hormonal differences were found in SW. CONCLUSION: Only the endurance training of CY and TR induced androgen deficiency without apparent alteration of BMD.  相似文献   

5.
The circadian rhythms of serum luteinizing hormone, follicle-stimulating hormone, testosterone (T), free testosterone (fT), sex hormone-binding globulin (SHBG), oestradiol, cortisol and dehydroepiandrosterone sulphate (DHA-s) have been investigated in 5 normal male adults and 6 elderly men. Circadian rhythms were detected statistically significant (p less than 0.05) by population mean cosinor analysis, for T, fT, cortisol and DHA-s in the young group. In the elderly population, serum cortisol showed a clear circadian rhythm, although with some phase modification, whereas DHA-s secretion lost its circadian rhythmicity. This demonstrates that ageing differently affects the two major adrenal functions, glucocorticoid and androgenic; further, the data suggest that an independent adrenal androgen-regulating system could be selectively impaired in the older subjects. In the elderly group the loss of T circadian rhythm was confirmed, but a statistically significant circadian rhythm of fT was recorded. It was characterized by a marked phase advance and not related with the SHBG modifications found in elderly men. This finding leads us to reconsider the role of fT, which appears more sensitive than total T, in studying circadian rhythm of gonadal androgen secretion.  相似文献   

6.
The hypothalamic-pituitary-gonadal system was investigated in drug free young men with either mania or acute schizophrenia and in age matched controls by measuring, at frequent intervals during a 17 hour "neuroendocrine day," plasma concentrations of luteinising hormone (LH), follicle stimulating hormone, prolactin, testosterone, sex hormone binding globulin (SHBG), and cortisol. Plasma LH in mania was significantly increased compared with the control value at all time periods and increased in the morning and evening samples compared with values in the schizophrenic patients. Plasma prolactin and cortisol concentrations were significantly greater in mania and schizophrenia compared with control values at several times during the day, but there were no significant between group differences in plasma testosterone or SHBG. These results show that in young men with mania there is a major disturbance in the central mechanisms that control the release of LH, the control of prolactin and cortisol secretion is abnormal in mania and acute schizophrenia, and plasma LH concentrations may provide a useful hormonal diagnostic test for mania.  相似文献   

7.
We studied 130 healthy aged women (n = 57) and men (n = 73), age 65-88 yr, with age-related reductions in insulin-like growth factor I and gonadal steroid levels to assess the interrelationships between cortisol and growth hormone (GH) secretion and whether these relationships differ by sex. Blood was sampled every 20 min from 8:00 PM to 8:00 AM; cortisol was measured by RIA and GH by immunoradiometric assay, followed by deconvolution analyses of hormone secretory parameters and assessment of approximate entropy (ApEn) and cross-ApEn. Cortisol mass/burst, cortisol production rate, and mean and integrated serum cortisol concentrations (P < 0.0005), and overnight basal GH secretion (P < 0.05), were elevated in women vs. men. Integrated cortisol concentrations were directly related to most measures of GH secretion in women (P < 0.01) and with mean and integrated GH concentrations in men (P < 0.05). Integrated GH concentrations were directly related to mean and integrated cortisol levels in women (P < 0.005) and men (P < 0.05), with no sex differences. There were no sex differences in cortisol or GH ApEn values; however, the cross-ApEn score was greater in women (P < 0.05), indicating reduced GH-cortisol pattern synchrony in aged women vs. men. There were no significant relationships of integrated cortisol secretion with GH ApEn, or vice versa, in either sex. Thus postmenopausal women appear to maintain elevated cortisol production in patterns that are relatively uncoupled from those of GH, whereas mean hormone outputs remain correlated.  相似文献   

8.
This investigation examined hormonal adaptations to acute resistance exercise and determined whether training adaptations are observed within an 8-week period in untrained men and women. The protocol consisted of a 1-week pre-conditioning orientation phase followed by 8 weeks of heavy resistance training. Three lower-limb exercises for the quadriceps femoris muscle group (squat, leg press, knee extension) were performed twice a week (Monday and Friday) with every other Wednesday used for maximal dynamic 1 RM strength testing. Blood samples were obtained pre-exercise (Pre-Ex), immediately post-exercise (IP), and 5 min post-exercise (5-P) during the first week of training (T-1), after 6 weeks (T-2) and 8 weeks (T-3) of training to determine blood concentrations of whole-blood lactate (LAC), serum total testosterone (TT), sex-hormone binding globulin (SHBG), cortisol (CORT) and growth hormone (GH). Serum TT concentrations were significantly (P ≤ 0.05) higher for men at all time points measured. Men did not demonstrate an increase due to exercise until T-2. An increase in pre-exercise concentrations of TT were observed both for men and women at T-2 and T-3. No differences were observed for CORT between men and women; increases in CORT above pre-exercise values were observed for men at all training phases and at T-2 and T-3 for women. A reduction in CORT concentrations at rest was observed both in men and women at T-3. Women demonstrated higher pre-exercise GH values than men at all training phases; no changes with training were observed for GH concentrations. Exercise-induced increases in GH above pre-exercise values were observed at all phases of training. Women demonstrated higher serum concentrations of SHBG at all time points. No exercise-induced increases were observed in men over the training period but women increased SHBG with exercise at T-3. SHBG concentrations in women were also significantly higher at T-2 and T-3 when compared to T-1 values. Increases in LAC concentrations due to exercise were observed both for men and women for all training phases but no significant differences were observed with training. These data illustrate that untrained individuals may exhibit early-phase endocrine adaptations during a resistance training program. These hormonal adaptations may influence and help to mediate other adaptations in the nervous system and muscle fibers, which have been shown to be very responsive in the early phase of strength adaptations with resistance training. Accepted: 11 December 1997  相似文献   

9.
Serum thyroid function tests (T4, T3, rT3 and TSH levels) and measures of peripheral thyroid hormone action (serum dopamine-beta-hydroxylase activity (DBH) and sex hormone binding globulin (SHBG] were determined in 6 women before and one month after initiating an aerobic physical conditioning program. The same measurements were made in a control group of 6 women who did not increase their activity during this time. In physically conditioned subjects, the resting heart rate decreased from 65.1 +/- 3.9 (mean +/- SE) at baseline to 58.0 +/- 2.9 beats per minute after one month (P less than 0.025), indicating an appreciable state of physical conditioning was achieved. However, there were no statistically significant changes in thyroid function test, serum DBH or SHBG levels in either the physically conditioned or the control group. These data indicate that being physically conditioned has a negligible effect on thyroid status.  相似文献   

10.
Testosterone (T) and cortisol (C) were assayed from saliva samples given by young men (n = 28) and women (n = 32) before, during, and after competing with a same-sex partner in a video game. The T response to the competition is different in each sex; the C response is the same. Male results confirm prior reports of a precontest rise in testosterone. Male results did not confirm previous findings that, after a contest, the testosterone of winners is higher than that of losers, perhaps because the video game contest produced little mood difference between male winners and losers. Unlike male testosterone, female testosterone generally decreased throughout the experiment. Trends in T and C are parallel in women but not in men. Apparently T works differently in competition between men than between women.  相似文献   

11.
This study was performed on 13 professional race-cyclists to examine changes in sex hormone binding globulin (SHBG), high density lipoprotein cholesterol (HDL-C) and serum lipid concentrations after training and after competition. While SHBG, total cholesterol and phospholipids increased and free fatty acids (FFA) decreased significantly during training, HDL-C and FFA increased and SHBG and triglycerides (TG) decreased significantly during the competition period. These latter changes in serum lipids and lipoproteins were assumed to be a direct effect of utilisation of muscle and plasma TG as fuels for exertion occurring only in extreme exercise. Changes in SHBG concentrations indicated that they were dependent on the conditions of the physical effort and could be related not only to the concentrations of androgens but also to the reduction in body mass.  相似文献   

12.
The pyrethroids are a class of natural and synthetic pesticides which were associated with an epidemic of gynecomastia in Haitian men in 1981. In the present study we tested several pyrethroids for their ability to interact with androgen binding sites in dispersed, intact human genital skin fibroblasts and in human plasma to sex hormone binding globulin (SHBG). All the pyrethroids tested inhibited fibroblast binding of [3H]methyltrienolone (R1881) at 22 degrees C with the following rank order of potency:pyrethrins greater than bioallethrin greater than fenvalerate greater than fenothrin greater than fluvalinate greater than permethrin greater than resmethrin. 50% displacement of [3H]R1881 binding to fibroblast androgen receptors was achieved by 1.5-44 x 10(-5) M concentrations of the competitors, respectively. Previous studies with cimetidine, a known inhibitor of androgen receptor binding, showed 50% competition at a concentration of 1.4 x 10(-4) M in this system. Scatchard analysis of binding experiments performed with increasing concentrations of [3H]R1881 in the presence of the pyrethroids indicated that the binding inhibition was competitive. On the other hand, of the pyrethroids examined only the pyrethrins (50% inhibition) and bioallethrin (43% inhibition) were able to displace [3H]testosterone from SHBG when tested at a concentration of 10(-4) M. These data indicate that a novel class of non-steroidal compounds, the pyrethroids, can interact competitively with human androgen receptors and SHBG. These findings provide a mechanism by which chronic exposure of humans or animals to pesticides containing these compounds may result in disturbances in endocrine effects relating to androgen action.  相似文献   

13.
The aim of this study was to determine the effect of both acute exercise and maintained training during a period of competition (3 mo, at the start of the season) on iron metabolism in sportsmen on a professional volleyball team. Twelve sportsmen volunteered for this study. The exercise test was performed on a mechanically braked Monark cycle ergometer and consisted of a triangular progressive test. Three blood samples were obtained in each test: at rest, just after exercise, and after recovery. The following hematological parameters were determined: red blood count (RBC), hemoglobin (Hb) and hematocrit (Hto), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), total proteins (TP), serum iron (Fe) and total iron-binding capacity (TIBC), ferritin (FER), transferrin (TRF), haptoglobin (HPT), and serum cortisol (COR) concentrations. We have found changes in hematological and biochemical variables related to Fe metabolism during the study. The changes observed could be the result of hemoconcentration processes after exercise and, at least in part, to physical stress and muscular damage. We conclude that athletes, after a period of adaptation, with a good plan of work/recovery series, undergo a biological redistribution on hematological and biochemical parameters concerning Fe metabolism during the training and competition period. Also, daily Fe supplementation could restore and mask the true repercussions of maintained training observed in other sports.  相似文献   

14.
Testosterone and other anabolic-androgenic steroids enhance athletic performance in men and women. As a result, exogenous androgen is banned from most competitive sports. However, due to variability in endogenous secretion, and similarities with exogenous testosterone, it has been challenging to establish allowable limits for testosterone in competition. Endogenous androgen production is dynamically regulated by both exercise and winning in competition. Furthermore, testosterone may promote athletic performance, not only through its long-term anabolic actions, but also through rapid effects on behavior. In women, excess production of endogenous testosterone due to inborn disorders of sexual development (DSD) may convey a competitive advantage. For many years, female competitors have been subject to tests of sexual genotype and phenotype known as gender verification. Although gender verification has not identified any normal man competing as a woman, this process has identified women athletes with DSD. As understanding of DSD has expanded in recent years, women with DSD are increasingly able to continue athletic competition.  相似文献   

15.
Objective: This study was carried out to investigate the role of sex in the regulation of the hypothalamic‐pituitary‐adrenal (HPA) axis and its relationship with testosterone levels in male and female obesity. Research Methods and Procedures: Twenty‐two obese men (OB‐M) and 29 obese women (OB‐W) participated in the study. Two groups of normal weight men (NW‐M) and women (NW‐W), respectively, served as controls. In basal conditions, blood concentrations of major androgens, sex hormone—binding protein, and gonadotropins were assessed, and the free androgen index (testosterone ×100/ sex hormone‐binding globulin) was calculated. All subjects underwent a combined corticotropin‐releasing hormone plus arginine‐vasopressin stimulation test. Results: OB‐M and NW‐M had higher basal adrenal cortical tropic hormone (ACTH) and cortisol levels than their female counterparts. In addition, ACTH, but not cortisol basal, levels were significantly higher in obese than in normal weight controls in both sexes. OB‐W had a higher response than OB‐M to the combined corticotropin‐releasing hormone plus arginine‐vasopressin test of both ACTH and cortisol [expressed as incremental percentage of area under the curve (AUC%)]. The same finding was present between NW‐W and NW‐M. Basal luteinizing hormone levels were negatively correlated to ACTHAUC% in both OB‐W and OB‐M. In the OB‐W, however, a positive correlation was found between cortisolAUC% and testosterone (r = 0.48; p = 0.002), whereas a tendency toward a negative correlation was present in OB‐M. Discussion: In conclusion, we have shown a significant positive relationship between the activity of the HPA axis and testosterone in obese women, which suggests a partial responsibility of increased HPA axis activity in determining testosterone levels. In addition, it clearly seems that, as reported in normal weight subjects, a sex difference in the HPA axis activity still persists even in the presence of obesity.  相似文献   

16.
Serum sulphates of 5-androstene-3 beta,17 beta-diol (5-ADIOL-S), 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-DIOL-S) and dehydroepiandrosterone (DHEA-S), unconjugated androstene-dione (AD) and testosterone (T), sex hormone binding globulin (SHBG), free androgen index (FAI), 17 alpha-hydroxyprogesterone (17OHP), luteinising hormone (LH) and follicle stimulating hormone (FSH) were measured by specific radioimmunoassay in 28 hirsute women with polycystic ovarian disease (PCO) and in normal women (n = 73). Mean levels of steroids measured were significantly elevated, and SHBG significantly depressed, in the women with PCO with values (mean +/- SE) for 5-ADIOL-S (516 +/- 51 vs 267 +/- 10 nmol/l), 3 alpha-DIOL-S (130 +/- 9 vs 52 +/- 2 nmol/l), DHEA-S (7.3 +/- 0.5 vs 4.4 +/- 0.2 mumol/l), AD (11.3 +/- 1.1 vs 3.4 +/- 0.2 nmol/l), T (3.3 +/- 0.2 vs 1.5 +/- 0.1 nmol/l) and 17OHP (5.1 +/- 0.8 vs 2.8 +/- 0.2 nmol/l). SHBG levels were 31 +/- 2.9 vs 65 +/- 2.5 nmol/l, and the free androgen index [100 x T (nmol/l) divided by (SHBG nmol/l)] was 12.5 +/- 1.4 vs 2.4 +/- 0.1. The mean LH to FSH ratio was also elevated at 2.8 +/- 0.3. These studies suggest that the measurement of 5-ADIOL-S and DHEA-S may indicate adrenal gland involvement in PCO while 3 alpha-DIOL-S appears to be a reflection of peripheral androgen metabolism. A comprehensive biochemical profile of PCO should thus include the analysis of these sulphoconjugates as well as unconjugated steroids.  相似文献   

17.
Seven female and eight male elite junior skaters performed cycle ergometer tests at four different times during the 1987/1988 season. The tests consisted of a Wingate-type 30-s sprint test and a 2.5-min supramaximal test. The subjects were tested in February, May and September 1987 and in January 1988. Maximal oxygen consumption was measured during the 2.5-min test. With the exception of the maximal oxygen consumption of the women in May which was about 6% lower than in the other three tests, no seasonal changes in the test results could be observed--this, in spite of a distinct increase in training volume (from 10 to more than 20 h.week-1) and training intensity in the course of the season. When the test data were compared to those of elite senior skaters, it appeared that the junior skaters showed the same values for mean power output during the sprint test [14.2 (SD 0.4) W.kg-1 for the men and 12.6 (SD 0.5) W.kg-1 for the women] and maximal oxygen consumption [63.1 (SD 2.8) ml.kg-1.min-1 for the men and 55.3 (SD 3.5) ml.kg-1.min-1 for the women, respectively] as found for senior skaters. It seemed, therefore, that the effects of training in these skaters had already levelled off in the period before they participated in this investigation. In contrast to previous studies, no relationship could be shown between the test results and skating performance. This was most likely due to the homogenous character of the groups (mean standard deviations in power and oxygen consumption were only 5%).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Fecal testosterone and cortisol levels were analyzed from six wild male muriquis (Brachyteles arachnoides) over a 19-month period at the Esta??o Biológica de Caratinga in Minas Gerais, Brazil, to investigate the hormonal correlates of seasonal sexual behavior and environmental conditions. Group mean testosterone levels based on weekly samples from the six males did not differ between copulatory and noncopulatory periods or between rainy and dry seasons. Cortisol levels did change with copulatory periods, and were significantly higher during the second dry season, when mating continued following an exceptionally heavy rainy season, than during the first dry season, when mating ceased. Males exhibited individual variation in the timing of their hormone shifts relative to their sexual activity, but neither hormone levels nor sexual activity were related to male age. Despite individual differences in the timing of testosterone fluctuations around the onset and offset of the copulatory season, all males exhibited elevated cortisol concentrations following a slight increase in testosterone at the beginning of the copulatory season. Both the lack of significant changes in testosterone levels with the onset of the rainy and copulatory season and the lack of prebreeding increases in cortisol may be related to the low levels of overt aggression displayed by male muriquis over access to mates.  相似文献   

19.
Knowledge of the basic reproductive physiology of snow leopards is required urgently in order to develop a suitable management conditions under captivity. In this study, the long-term monitoring of concentrations of three steroid hormones in fecal matter of three female snow leopards was performed using enzyme immunoassays: (1) estradiol-17β, (2) progesterone and (3) cortisol metabolite. Two of the female animals were housed with a male during the winter breeding season, and copulated around the day the estradiol-17β metabolite peaked subsequently becoming pregnant. The other female was treated in two different ways: (1) first housed with a male in all year round and then (2) in the winter season only. She did not mate with him on the first occasion, but did so latter around when estradiol-17β metabolite peaked, and became pseudopregnant. During pregnancy, progesterone metabolite concentrations increased for 92 or 94 days, with this period being approximately twice as long as in the pseudopregnant case (31, 42, 49 and 53 days). The levels of cortisol metabolite in the pseudopregnant female (1.35 μg/g) were significantly higher than in the pregnant females (0.33 and 0.24 μg/g) (P<0.05). Similarly, during the breeding season, the levels of estradiol-17β metabolite in the pseudopregnant female (2.18 μg/g) were significantly higher than those in the pregnant females (0.81 and 0.85 μg/g) (P<0.05). Unlike cortisol the average levels of estradiol-17β during the breeding season were independent of reproductive success.The hormone levels may also be related to housing conditions and the resulting reproductive success in female leopards. The female housed with a male during the non-breeding season had high levels of cortisol metabolites and low levels of estradiol-17β in the breeding season, and failed to become pregnant. This indicates that housing conditions in snow leopards may be an important factor for normal endocrine secretion and resulting breeding success.  相似文献   

20.
Serum sulphates of 5-androstene-3 beta,17 beta-diol (5-ADIOL-S), 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-DIOL-S) and dehydroepiandrosterone (DHEA-S), as well as 5 alpha-androstane-3 alpha,17 beta-diol glucuronide (3 alpha-DIOL-G) and unconjugated androstenedione (AD) and testosterone (T), sex hormone binding globulin (SHBG), free androgen index (FAI) and 17 alpha-hydroxyprogester-one (17OHP) were measured by specific radioimmunoassays (RIA) in 14 women with late-onset 21-hydroxylase deficiency (LOCAH), and in normal women (n = 73). The diagnosis of LOCAH was made on the finding of a (17OHP) response level greater than 30 nmol/l following ACTH stimulation, and/or an elevation of urinary metabolites of 17OHP. Mean values for serum concentrations of all steroids measured and the free androgen index (100 X T nmol/l divided by SHBG nmol/l) were significantly elevated, and SHBG levels depressed in patients with LOCAH. These studies show that in LOCAH, in addition to the unconjugated steroids AD and T, the sulphoconjugated steroids DHEA-S, 5-ADIOL-S and 3 alpha-DIOL-S are increased, as is the glucuronide conjugate 3 alpha-DIOL-G and the index of bioavailable testosterone (FAI), and that mean SHBG levels are depressed. These data suggest that as well as AD, 5-ADIOL-S and DHEA-S may act as pro-hormones for more potent steroids (T and 5 alpha-dihydrotestosterone) in peripheral tissues, while 3 alpha-DIOL-S and 3 alpha-DIOL-G may both reflect peripheral androgen metabolism in patients with LOCAH.  相似文献   

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