Adrenals

Ringer, Robert K.

doi:10.1007/978-3-642-96274-5_20

Cited by 8 publications

(6 citation statements)

References 53 publications

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“…Samples were collected at various times of the day (0900-2000 h), however circadian rhythms in hormone concentrations were unlikely to have produced any within-day variation due to the continuous 24 h daylight (Ringer, 1976 and references therein); furthermore, Vleck and Van Hook (2002) found no evidence that circadian rhythms operate in Adelie penguins in this context.…”

Section: Sample Collectionmentioning

confidence: 97%

“…Corticosterone is the main avian glucocorticoid (Ringer, 1976), and has been traditionally measured from blood plasma using radio immunoassays (RIAs) or enzyme immunoassays (EIAs) (Adkins-Regan, 2005). More recently, however, the measurement of corticosterone (and its metabolites), as well as other steroid hormones, from faecal samples has become increasingly popular (Adkins-Regan, 2005); for example, the method has been used extensively in recent studies measuring steroid hormones in birds (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae

et al. 2009

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Abstract. 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 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 'snapshot' concentration. Our data indicate that faecal sampling appears more suitable for assessing baseline hormone concentrations, while plasma sampling may best define immediate responses to environmental events. Consequently, future studies should ensure they select the most appropriate matrix and method of hormone measurement to answer their research questions.

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Section: Sample Collectionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae

et al. 2009

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“…Avian adrenal anatomy and physiology have been reviewed by Ringer (1976) and Freeman (1983). In all avian species studied, corticosterone is considered the major glucocorticoid (Lothrop et al, 1985;Zenoble et al, 1985a,b;Walsh et al, 1985).…”

Section: Introductionmentioning

confidence: 99%

Action of acth^{1 ‐24}upon plasma corticosterone concentrations in racing pigeons(Columba Livia domestica)

Lumeij

Boschma²,

Mol

et al. 1987

Avian Pathology

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SUMMARYTo establish the optimal dose and sampling times for the ACTH stimulation test in racing pigeons, plasma corticosterone concentrations were measured in experimental animals at 0, 30, 60, 90, 120 and 150 min after intramuscular administration of different doses of ACTH 1-24 .Baseline corticosterone concentrations varied between less than 0.2 and 1.24 μtg/dl. To evaluate adrenocortical function the clinician is advised to take a blood sample before and at 60 or 90 min after stimulation with 50 μg ACTH or at 30, 60, 90 or 120 min after stimulation with 125 μg ACTH. In healthy individuals a ten-to hundred-fold increase over baseline (t=0) corticosterone concentrations and absolute concentrations in the range of 2.2 to 15.0 μg/dl can be expected in the post stimulation sample.

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“…This forced change recorvers to the normal state after 2 months. Many studies employed different conditions to induce forced molting (Cole-and Hutt, 1928;Schaffner, 1954;Tanabe et al, 1957;Harris and Schaffner, 1957;Nakazawa et al, 1968;Ringer, 1976;Scanes et al, 1979;Pethes et al, 1982) van Bohemen et al, 1981;Korsgaard et al, 1986), Xenopus (Wallace and Jared, 1969;Kato et al, 1986;Holland and Wangh, 1987). Thus, vitellogenin synthesis is largely coupled with egg production under the control of the endocrine system.…”

mentioning

confidence: 99%

Acute Decrease in Vitellogenin Synthesis by deprivation of food and Water in Laying Hens.

et al. 1990

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Adrenals

Cited by 8 publications

References 53 publications

Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae

Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae

Action of acth^{1 ‐24}upon plasma corticosterone concentrations in racing pigeons(Columba Livia domestica)

Acute Decrease in Vitellogenin Synthesis by deprivation of food and Water in Laying Hens.

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Adrenals

Cited by 8 publications

References 53 publications

Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae

Comparing plasma and faecal measures of steroid hormones in Adelie penguins Pygoscelis adeliae

Action of acth1 ‐24upon plasma corticosterone concentrations in racing pigeons(Columba Livia domestica)

Acute Decrease in Vitellogenin Synthesis by deprivation of food and Water in Laying Hens.

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Action of acth^{1 ‐24}upon plasma corticosterone concentrations in racing pigeons(Columba Livia domestica)