Inter-annual repeatability and age-dependent changes in plasma testosterone levels in a longitudinally monitored free-living passerine bird

Oecologia ◽  
2021 ◽  
Author(s):  
Martin Těšický ◽  
Tereza Krajzingrová ◽  
Jiří Eliáš ◽  
Hana Velová ◽  
Jana Svobodová ◽  
...  
Keyword(s):  
Passerine Bird ◽  
Plasma Testosterone ◽  
Free Living ◽  
Testosterone Levels ◽  
Age Dependent

scholarly journals Inter-annual stability and age-dependent changes in plasma testosterone levels in a longitudinally monitored free-living passerine bird

2020 ◽  
Author(s):  
Martin Tešický ◽  
Tereza Krajzingrová ◽  
Jiří Eliáš ◽  
Hana Velová ◽  
Jana Svobodová ◽  
...  
Keyword(s):  
Resource Allocation ◽  
Hormonal Regulation ◽  
Parus Major ◽  
Passerine Bird ◽  
Plasma Testosterone ◽  
Free Living ◽  
Testosterone Levels ◽  
Long Term Stability ◽  
Age Related ◽  
Age Dependent

AbstractWhile seasonal trends in the testosterone-driven hormonal regulation of resource allocation are known from cohort population samples, data on the inter-annual individual stability of blood plasma testosterone levels in wild birds are lacking, and our understanding of age-dependent changes is limited. We assessed plasma testosterone levels in 105 samples originating from 49 repeatedly captured free-living great tits (Parus major) to investigate their relative long-term stability and lifetime changes. Furthermore, we examined the inter-annual stability of selected condition-related traits (carotenoid- and melanin-based plumage ornamentation, ptilochronological feather growth rate, body mass, and haematological heterophil/lymphocyte ratio) and their relationships to testosterone levels. We show that testosterone levels in both sexes are inter-annually repeatable, both in their absolute values and individual ranks (indicating the maintenance of relative status in a population), yet with higher stability in females. Despite this stability, in males we found a quadratic dependence of testosterone levels on age, with a peak in midlife. In contrast, female testosterone levels showed no lifetime trend. The inter-annual stability of condition-related traits was mostly moderate and unrelated to plasma testosterone concentrations. However, males with elevated testosterone had significantly higher carotenoid-pigmented yellow plumage brightness, presumably serving as a sexually selected trait. Showing inter-annual stability in testosterone levels, this research opens the way to further understanding of the causes of variation in fitness-related traits. Based on a unique longitudinal dataset, this study demonstrates that male plasma testosterone undergoes age-related changes that may regulate resource allocation. Our results thus demonstrate that male birds undergo hormonal senescence similar to mammals.

scholarly journals Neuroendocrine patterns underlying seasonal song and year-round territoriality in male black redstarts

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Camila P. Villavicencio ◽  
Harriet Windley ◽  
Pietro B. D’Amelio ◽  
Manfred Gahr ◽  
Wolfgang Goymann ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Life Cycle ◽  
Receptor Expression ◽  
Territorial Behavior ◽  
Plasma Testosterone ◽  
Estrogen Receptor Expression ◽  
Free Living ◽  
Testosterone Levels ◽  
Life Cycle Stages ◽  
Song Control

Abstract Background The connection between testosterone and territoriality in free-living songbirds has been well studied in a reproductive context, but less so outside the breeding season. To assess the effects of seasonal androgenic action on territorial behavior, we analyzed vocal and non-vocal territorial behavior in response to simulated territorial intrusions (STIs) during three life-cycle stages in free-living male black redstarts: breeding, molt and nonbreeding. Concurrently, we measured changes in circulating testosterone levels, as well as the mRNA expression of androgen and estrogen receptors and aromatase in the preoptic, hypothalamic and song control brain areas that are associated with social and vocal behaviors. Results Territorial behavior and estrogen receptor expression in hypothalamic areas did not differ between stages. But plasma testosterone was higher during breeding than during the other stages, similar to androgen receptor and aromatase expression in the preoptic area. The expression of androgen receptors in the song control nucleus HVC was lower during molt when birds do not sing or sing rarely, but similar between the breeding and the nonbreeding stage. Nevertheless, some song spectral features and the song repertoire differed between breeding and nonbreeding. Territorial behavior and song rate correlated with the expression of steroid receptors in hypothalamic areas, and in the song control nucleus lMAN. Conclusions Our results demonstrate seasonal modulation of song, circulating testosterone levels, and brain sensitivity to androgens, but a year-round persistency of territorial behavior and estrogen receptor expression in all life-cycle stages. This suggests that seasonal variations in circulating testosterone concentrations and brain sensitivity to androgens is widely uncoupled from territorial behavior and song activity but might still affect song pattern. Our study contributes to the understanding of the complex comparative neuroendocrinology of song birds in the wild.

The effects of terrestrial and breeding densities on corticosterone and testosterone levels in spotted salamanders, Ambystoma maculatum

2004 ◽  
Vol 82 (11) ◽  
pp. 1795-1803 ◽  
Author(s):  
Mark D Cooperman ◽  
J Michael Reed ◽  
L Michael Romero
Keyword(s):  
Plasma Concentrations ◽  
High Density ◽  
Ambystoma Maculatum ◽  
Plasma Testosterone ◽  
Adult Density ◽  
Free Living ◽  
Testosterone Levels ◽  
Potential Competition

We examined plasma concentrations of corticosterone (CORT) and testosterone in male free-living and captive spotted salamanders, Ambystoma maculatum (Shaw, 1802), to determine if (i) they mounted significant CORT responses to conspecifics in captive enclosures during potential competition for limited burrows; (ii) artificially induced, increased breeding densities altered CORT and testosterone levels in a free-living population; and (iii) testosterone in free-living males varied seasonally. We found increased baseline CORT in captive male spotted salamanders exposed to conspecifics under high densities (4 animals with only 1 burrow). Original residents of the cage, however, had significantly higher baseline CORT titers than did newly introduced animals, and titers were significantly higher in animals cohabiting a burrow than those remaining outside the burrow. This suggests that spotted salamanders perceive con specifics as threats for burrows and become stressed when forced to share these resources. In contrast, free-living spotted salamanders during breeding showed no significant increases in baseline CORT or testosterone in high-density treatments. This suggests that increased adult density during breeding is not stressful to these salamanders. Finally, spotted salamanders had greater plasma testosterone titers in fall than in spring, suggesting that they are dissociated breeders.

INFLUENCE OF METYRAPONE ON PLASMA CONCENTRATIONS OF TESTOSTERONE AND ANDROSTENEDIONE IN MAN

1971 ◽  
Vol 68 (3) ◽  
pp. 576-584 ◽  
Author(s):  
K. O. Nilsson ◽  
B. Hökfelt
Keyword(s):  
Body Weight ◽  
Male Patient ◽  
Gradual Increase ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Normal Males ◽  
A Minor ◽  
Secondary Hypogonadism

ABSTRACT Metyrapone was administered either orally, 750 mg every four h, in a total of six doses, or intravenously 30 mg per kg body weight as a four h infusion. In three males with normal endocrine functions, metyrapone given orally or intravenously induced a fall in plasma testosterone and an elevation of androstenedione within 2–8 h. When metyrapone was administered to a patient given dexamethasone to suppress endogenous ACTH production, the androstenedione levels did not alter whereas the testosterone levels showed a slight, transient decrease. In two normal females metyrapone administration was followed by a marked increase in plasma androstenedione whereas testosterone showed only a minor, gradual increase. In one male patient with Addison's disease the basal plasma testosterone was normal whereas the level of androstenedione was low. Following metyrapone intravenously, there was a slight suppression of plasma testosterone but no change in the androstenedione concentration. In one patient with primary hypogonadism, two with secondary hypogonadism and two with Klinefelter's syndrome the plasma testosterone was low under basal conditions and did not change following metyrapone. Basal plasma androstenedione was within the range for normal males and increased markedly following metyrapone in all the cases.

Effects of oestradiol benzoate (OeB) and human chorionic gonadotrophin (hCG) on the testes and accessory sex glands of the rat

1981 ◽  
Vol 96 (2) ◽  
pp. 273-280 ◽  
Author(s):  
Mridula Chowdhury ◽  
Robert Tcholakian ◽  
Emil Steinberger
Keyword(s):  
Treated Group ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Control Group ◽  
Intact Male ◽  
Intact Control ◽  
Testosterone Levels ◽  
Oestradiol Benzoate ◽  
Direct Inhibitory Effect

Abstract. It has been suggested that treatment of intact male rats with oestradiol benzoate (OeB) causes an interference with testosterone (T) production by the testes by a direct inhibitory effect on steroidogenesis. To test this hypothesis, different doses (5, 10 or 25 IU) of hCG were administered concomitantly with 50 μg of OeB to adult intact or hypophysectomized male rats. The testicular and plasma testosterone, and serum hCG levels were determined. The sex accessory weights were recorded. In the intact OeB-treated group of animals, hCG stimulated both the secondary sex organs and plasma testosterone levels above the intact control group. However, in hypophysectomized animals, although plasma testosterone levels increased above that of intact controls, their secondary sex organ weights did not. Moreover, inspite of high circulating hCG levels, the testicular testosterone content and concentration remained suppressed in OeB-treated animals. The reason for such dichotomy of hCG action on OeB-treated animals is not clear at present.

scholarly journals The serotonin transporter gene and female personality variation in a free-living passerine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bert Thys ◽  
Andrea S. Grunst ◽  
Nicky Staes ◽  
Rianne Pinxten ◽  
Marcel Eens ◽  
...  
Keyword(s):  
Serotonin Transporter ◽  
Strong Support ◽  
Serotonin Transporter Gene ◽  
Female Aggression ◽  
Nucleotide Polymorphisms ◽  
Transporter Gene ◽  
Evolutionary Potential ◽  
Free Living ◽  
Age Related ◽  
Age Dependent

AbstractQuantifying variation in behaviour-related genes provides insight into the evolutionary potential of repeatable among-individual variation in behaviour (i.e. personality). Yet, individuals typically also plastically adjust their behaviour in response to environmental conditions and/or age, thereby complicating the detection of genotype–phenotype associations. Here, using a population of free-living great tits (Parus major), we assessed the association between single nucleotide polymorphisms (SNPs) in the serotonin transporter gene (SERT) and two repeatable behavioural traits, i.e. female-female aggression and female hissing behaviour. For female-female aggression, a trait showing age-related plasticity, we found no evidence for associations with SERT SNPs, even when assessing potential age-dependent effects of SERT genotype on aggression. We also found no strong support for associations between SERT SNPs and hissing behaviour, yet we identified two synonymous polymorphisms (exon 13 SNP66 and exon 12 SNP144) of particular interest, each explaining about 1.3% of the total variation in hissing behaviour. Overall, our results contribute to the general understanding of the biological underpinning of complex behavioural traits and will facilitate further (meta-analytic) research on behaviour-related genes. Moreover, we emphasize that future molecular genetic studies should consider age-dependent genotype–phenotype associations for behavioural trait (co)variation, as this will vastly improve our understanding of the proximate causes and ultimate consequences of personality variation in natural populations.

Association Between Androgen Receptor Gene CAG Repeat Polymorphism and Plasma Testosterone Levels in Postmenopausal Women

2005 ◽  
Vol 12 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Ilma Simoni Brum ◽  
Poli Mara Spritzer ◽  
Franyoise Paris ◽  
Maria Augusta Maturana ◽  
Franyoise Audran ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Postmenopausal Women ◽  
Receptor Gene ◽  
Androgen Receptor Gene ◽  
Cag Repeat ◽  
Plasma Testosterone ◽  
Repeat Polymorphism ◽  
Testosterone Levels

Lymphocyte subset distribution and natural killer cell activity in men with idiopathic hypogonadotropic hypogonadism

1991 ◽  
Vol 124 (4) ◽  
pp. 399-404 ◽  
Author(s):  
Wieland Kiess ◽  
Linda L. Liu ◽  
Nicholas R. Hall
Keyword(s):  
Natural Killer Cell ◽  
Natural Killer ◽  
Natural Killer Cell Activity ◽  
Hypogonadotropic Hypogonadism ◽  
Killer Cell ◽  
Cell Activity ◽  
Hormonal Treatment ◽  
Plasma Testosterone ◽  
Idiopathic Hypogonadotropic Hypogonadism ◽  
Testosterone Levels

Abstract. Sex-related differences in immune responsiveness are mediated at least in part by sex steroid hormones. Lymphocyte subset distribution in peripheral blood and natural killer cell function both have been reported to be under hormonal control. In order to gain more insight into sex steroid hormone action on the immune system, we have measured the lymphocyte subset distribution and natural killer cell activity in 18 men with idiopathic hypogonadotropic hypogonadism before treatment, and after hormonal treatment had normalized plasma testosterone levels. In untreated patients, the mean plasma testosterone concentrations were significantly lower than those in the treated men (3.0 ± 0.5 nmol/l vs 16 ± 1.7 nmol/l, p < 0.001). The percentage of peripheral CD3+ lymphocytes, CD8+ cells, the CD4+/CD8+ ratio, and the natural killer cell activity of peripheral mononuclear cells measured in a 51Cr release assay against target K 562 cells did not differ between patients with idiopathic hypogonadotropic hypogonadism and healthy adults, and most importantly, did not change during hormonal treatment which normalized plasma testosterone levels in the patients. In contrast, the percentage of peripheral CD4+ cells was significantly higher in untreated patients compared with normal adult subjects or patients with idiopathic hypogonadotropic hypogonadism after hormonal treatment that resulted in normal plasma testosterone levels (53 ± 2 vs 47 ± 2, p < 0.05). It should be noted that the percentage of peripheral CD 16+ cells was significantly lower in untreated men with low plasma testosterone levels than in normal controls. The percentage of CD16+ cells in peripheral venous blood rose significantly after hormonal treatment restored plasma testosterone levels to normal (6 ± 1 vs 11 ± 1, p < 0.001). In addition, the percentage of peripheral CD16+ cells correlated significantly with the plasma testosterone levels measured in men with idiopathic hypogonadotropic hypogonadism (r = 0.534, p < 0.001). In conclusion, both the percentage of peripheral CD4+ cells (T-helper lymphocytes) and peripheral CD16+ cells (non-T-non-B cells) are related to the plasma testosterone levels in men with idiopathic hypogonadotropic hypogonadism. These data suggest that in vivo human immune cells are under the regulatory influence of endogenous sex steroids.

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