58,701 research outputs found
The reward value of infant facial cuteness tracks within-subject changes in womenâs salivary testosterone
âBaby schemaâ refers to infant characteristics, such as facial cues, that
positively influence cuteness perceptions and trigger caregiving and protective
behaviors in adults. Current models of hormonal regulation of parenting
behaviors address how hormones may modulate protective behaviors and
nurturance, but not how hormones may modulate responses to infant
cuteness. To explore this issue, we investigated possible relationships
between the reward value of infant facial cuteness and within-woman changes
in testosterone, estradiol, and progesterone levels. Multilevel modeling of
these data showed that infant cuteness was more rewarding when womenâs
salivary testosterone levels were high. Moreover, this within-woman effect of
testosterone was independent of the possible effects of estradiol and
progesterone and was not simply a consequence of changes in womenâs
cuteness perceptions. These results suggest that testosterone may modulate
differential responses to infant facial cuteness, potentially revealing a new
route through which testosterone shapes selective allocation of parental
resources
Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae
Physiological measurements of both stress and sex hormones are often used to estimate the consequences of natural or human-induced change in ecological studies of various animals. Different methods of hormone measurement exist, potentially explaining variation in results across studies; methods should be cross-validated to ensure that they correlate. We directly compared faecal and plasma hormone measurements for the first time in a wild free-living species, the Adelie penguin (Pygoscelis adeliae). Blood and faecal samples were simultaneously collected from individual penguins for comparison and assayed for testosterone and corticosterone (or their metabolites). Sex differences and variability within each measure, and correlation of values across measures were compared. For both hormones, plasma samples showed greater variation than faecal samples. Males had higher mean corticosterone concentrations than females, but the difference was only statistically significant in faecal samples. Plasma testosterone, but not faecal testosterone, was significantly higher in males than females. Correlation between sample types was poor overall, and weaker in females than in males, perhaps because measures from plasma represent hormones that are both free and bound to globulins, whereas measures from faeces represent only the free portion. Faecal samples also represent a cumulative measure of hormones over time, as opposed to a plasma âsnapshotâ concentration. Our data indicate that faecal sampling appears more suitable for assessing baseline hormone concentrations, whilst plasma sampling may best define immediate responses to environmental events. Consequently, future studies should ensure that they select the most appropriate matrix and method of hormone measurement to answer their research questions
Influences of various hormones on the megakaryocyte in bone-marrow tissue culture
In our study on the influences of various hormones and various endocrines on the megakaryocyte function by means of bone-marrow tissue culture, we obtained the following.
1. In the repeated administration of ACTH, cortisone, testosterone, progesterone, or thyroxin to guinea pigs, these hormones accelerated the megakaryocyte function, whereas estradiol on the contrary diminished the function.
2. The removal of such endocrines as the pituitary, adrenal, thyroid or testicles will diminish the megakaryocyte function, while removal of the ovaries accelerates it.
3. For the megakaryocytes in the hypophysectomized rats, ACTH acts most effectively to restore their function, followed by cortisone and pulverized thyroid, while testosterone has hardly any effect on the function.
4. ACTH, cortisone, prednisolone, testosterone, progesterone, and pulverized thyroid act directly on megakaryocytes so as to accelerate their function, while estradiol diminishes the megakaryocyte function. 5. For the megakaryocytes in idiopathic thrombocytopenic purpura
ACTH is most effective in restoring the function; for the megakaryocytes in hypoplastic anemia cortisone is most effective; and for the megakaryocytes in Banti's disease prednisolone is most effective in restoring the megakaryocyte function.</p
Gender ideology, same-sex peer group affiliation and the relationship between testosterone and dominance in adolescent boys and girls
Although the role of testosterone in the aetiology of social dominance is often suggested, surprisingly few studies have addressed the relationship between sex steroid hormones and dominance as a personality trait. In this paper, the relationship between testosterone and dominance is studied in a sample of adolescent boys and girls, taking into account the moderating role of gender ideology and same-sex peer group orientation. A direct association between free testosterone (FT) and dominance was found in girls but not in boys. In boys, masculine ideology moderated the relationship between FT and dominance, while in girls the relationship between FT and dominance was moderated by same-sex peer group affiliation
The Acute Responses of Different-sized Coronary Arteries to Testosterone
Coronary arteries supply blood to the myocardium. The blood flow within the coronary arteries is altered by various compounds produced within the body. Sex hormones such as testosterone are known to cause the relaxation of large coronary arteries. But the response to testosterone is greater in in vivo conditions compared to in vitro conditions. We hypothesize that the responses of LADs (left anterior descending arteries) and its side branches to testosterone are heterogeneous and testosterone-induced vasodilation is greater in its side branches. Therefore, our study was designed to determine the effect of testosterone in different-sized coronary arteries. LADs and one of its side branches were isolated from porcine hearts and mounted in organ baths to mimic in vivo conditions. The coronary arteries were then preconstricted with potassium chloride (KCl) and administered increasing concentrations of testosterone to determine if the responses to testosterone vary within different regions of the coronary circulation. The testosterone caused significant relaxation in both LADs and its side branches. However the side branches showed similar responses to testosterone as compared to the larger, upstream LADs. Further studies on androgen receptor expression using real time PCR indicated that androgen receptor expression was higher in LADs than its side branches. A third group of small coronary arteries exhibited greater androgen receptor expression than the LADs and its side branches. The enhanced testosterone-induced vascular reactivity exhibited in vivo may be at the level of the small coronary arteries, not the LAD and its side branches
Response of selected hormonal markers during training cycles on indian female swimmers
The present study was taken up to monitor the fluctuations of the hormones testosterone, cortisol and T/C (Testosterone/Cortisol) ratio concentrations during the three phases of training namely preparatory phase, pre-competitive phase and competitive phase in Indian female swimmers. Blood samples were collected at the completion of each phase to study the impact of training on these hormones. Our results reveal that the testosterone and T/C ratio significantly decreases whereas cortisol increases in the subsequent periodised cycle and it was due to the intensity and volume of training. Our study concludes that the intensity and volume of training has effects on these hormones and also, a swimmer with higher testosterone, lowest cortisol and highest T/C ratio has the highest percentage difference of performance record between the preparatory and competitive phase. Hence, monitoring of these hormones is essential to avoid overtraining and to enhance the performance of the swimmers
Associations between anxiety, body mass index, and sex hormones in women
Background: Several studies have shown a positive association between anxiety and obesity, particularly in women. We aimed to study whether sex hormone alterations related to obesity might play a role in this association. Patients and methods: Data for this study were obtained from a population-based cohort study (the LIFE-Adult-Study). A total of 3,124 adult women (970 premenopausal and 2,154 postmenopausal) were included into the analyses. The anxiety symptomatology was assessed using the GAD-7 questionnaire (cut-off â„ 10 points). Sex hormones were measured from fasting serum samples. Results: We did not find significant differences in anxiety prevalence in premenopausal obese women compared with normal-weight controls (4.8% vs. 5.5%). Both obesity and anxiety symptomatology were separately associated with the same sex hormone alteration in premenopausal women: higher total testosterone level (0.97 ± 0.50 in obese vs. 0.86 ± 0.49ânmol/L in normal-weight women, p = 0.026 and 1.04 ± 0.59 in women with vs. 0.88 ± 0.49ânmol/L in women without anxiety symptomatology, p = 0.023). However, women with anxiety symptomatology had non-significantly higher estradiol levels than women without anxiety symptomatology (548.0 ± 507.6 vs. 426.2 ± 474.0âpmol/L), whereas obesity was associated with lower estradiol levels compared with those in normal-weight group (332.7 ± 386.5 vs. 470.8 ± 616.0âpmol/L). Women with anxiety symptomatology had also significantly higher testosterone and estradiol composition (p = 0.006). No associations of sex hormone levels and BMI with anxiety symptomatology in postmenopausal women were found. Conclusions: Although both obesity and anxiety symptomatology were separately associated with higher testosterone level, there was an opposite impact of anxiety and obesity on estradiol levels in premenopausal women. We did not find an evidence that the sex hormone alterations related to obesity are playing a significant role in anxiety symptomatology in premenopausal women. This could be the explanation why we did not find an association between obesity and anxiety. In postmenopausal women, other mechanisms seem to work than in the premenopausal group
Cortisol levels are positively associated with pup-feeding rates in male meerkats
In societies of cooperative vertebrates, individual differences in contributions to offspring care are commonly substantial. Recent attempts to explain the causes of this variation have focused on correlations between contributions to care and the protein hormone prolactin, or the steroid hormone testosterone. However, such studies have seldom considered the importance of other hormones or controlled for non-hormonal factors that are correlative with both individual hormone levels and contributions to care. Using multivariate statistics, we show that hormone levels explain significant variation in contributions to pup-feeding by male meerkats, even after controlling for non-hormonal effects. However, long-term contributions to pup provisioning were significantly and positively correlated with plasma levels of cortisol rather than prolactin, while plasma levels of testosterone were not related to individual patterns of pup-feeding. Furthermore, a playback experiment that used pup begging calls to increase the feeding rates of male helpers gave rise to parallel increases in plasma cortisol levels, whilst prolactin and testosterone levels remained unchanged. Our findings confirm that hormones can explain significant amounts of variation in contributions to offspring feeding, and that cortisol, not prolactin, is the hormone most strongly associated with pup-feeding in cooperative male meerkats
Sex hormones in allergic conjunctivitis: altered levels of circulating androgens and estrogens in children and adolescents with vernal keratoconjunctivitis
PURPOSE:
Vernal keratoconjunctivitis (VKC) is a chronic allergic disease mainly affecting boys in prepubertal age and usually recovering after puberty. To evaluate a possible role of sex hormones in VKC, serum levels of sex hormones in children and adolescents with VKC were assessed.
METHODS:
12 prepubertal and 7 early pubertal boys with active VKC and 6 male patients with VKC in remission phase at late pubertal age and 48 healthy age and sex-matched subjects were included. Serum concentration of estrone, 17 beta-estradiol, dehydroepiandrosterone-sulfate, total testosterone and free testosterone, dihydrotestosterone (DHT), cortisol, delta-4-androstenedione, follicle-stimulating hormone, luteinizing hormone, and sex-hormones binding globuline (SHBG) were evaluated.
RESULTS:
Serum levels of Estrone were significantly increased in all groups of patients with VKC when compared to healthy controls (P < 0.001). Prepubertal and early pubertal VKC showed a significant decrease in DHT (P = 0.007 and P = 0.028, resp.) and SHBG (P = 0.01 and P = 0.002, resp.) when compared to controls and serum levels of SHBG were increased in late pubertal VKC in remission phase (P = 0.007).
CONCLUSIONS AND RELEVANCE:
VKC patients have different circulating sex hormone levels in different phases of the disease and when compared to nonallergic subjects. These findings suggest a role played by sex hormones in the pathogenesis and/or activity of VKC
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