Adrenal sensitivity to stress is maintained despite variation in baseline glucocorticoids in moulting seals

Champagne, Cory D.; Tift, Michael S.; Houser, Dorian S.; Crocker, Daniel E.

doi:10.1093/conphys/cov004

Cited by 25 publications

(44 citation statements)

References 58 publications

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“…The mid-molt period exhibiting the highest aldosterone concentrations and a decrease in both late fasting and late molting is identical to the pattern exhibited during a previous ACTH challenge study (Champagne et al, 2015). The similarity seen in free-ranging baseline concentrations and the ACTH challenge supports control by the HPA axis.…”

Section: Discussionsupporting

confidence: 79%

“…In a recent study in molting juvenile northern elephant seals, the HPA axis remained sensitive to ACTH stimulation regardless of varying baseline levels of glucocorticoids (Champagne et al, 2015). If sampled at the appropriate temporal scale, ACTH should be predictive of concentrations of cortisol concentrations in normal HPA axis regulation.…”

Section: Discussionmentioning

confidence: 95%

“…Angiotensin II then promotes release of aldosterone by the adrenal gland. Several studies have suggested that aldosterone is an important component of the stress response in marine mammals, being released in response to an ACTH challenge or perceptual stress (Champagne et al, 2015;Gulland et al, 1999;Houser et al, 2011;Thomson and Geraci, 1986). The regulation of aldosterone release by the HPA axis may reflect the need to alter kidney perfusion and lung perfusion during diving, inhibiting typical RAS regulation (Atkinson et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

“…Both thyroid hormone concentrations (total T3 (tT3) and total T4 (tT4)) varied between sexes, and tT4 concentrations declined over the fasting period in juveniles (Kelso et al, 2012). Cortisol levels increased dramatically during molting (Champagne et al, 2015) but did not increase across the Fall haul-out in this age class (Kelso et al, 2012). Together these features make yearling elephant seals an ideal study group to explore sex differences and associations between stress hormones, not confounded by differences in reproductive effort or behavior.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Variation in adrenal and thyroid hormones with life-history stage in juvenile northern elephant seals (Mirounga angustirostris)

Jelincic

Tift

Houser

et al. 2017

General and Comparative Endocrinology

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Section: Discussionsupporting

confidence: 79%

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Variation in adrenal and thyroid hormones with life-history stage in juvenile northern elephant seals (Mirounga angustirostris)

Jelincic

Tift

Houser

et al. 2017

General and Comparative Endocrinology

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“…, Champagne et al . , Keogh and Atkinson ). Furthermore, HPA axis activation, through ACTH administrations or handling effects, has been shown to stimulate aldosterone release in these taxa (Thomson and Geraci , Gulland et al .…”

Section: Discussionmentioning

confidence: 98%

Blubber cortisol qualitatively reflects circulating cortisol concentrations in bottlenose dolphins

Champagne

Kellar

Crocker

et al. 2016

Marine Mammal Science

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Stress hormones, released into circulation as a consequence of disturbance, are classically assayed from blood samples but may also be detected in a variety of matrices. Blubber and fecal samples can be remotely collected from free‐ranging cetaceans without the confounding hormone elevations associated with chase, capture, and handling required to collect blood samples. The relationship between cortisol concentrations in circulation with that of blubber and feces, however, is unknown. To assess these associations, we elevated cortisol by orally administering hydrocortisone for five days in five bottlenose dolphins. Voluntary blood and fecal samples were collected daily; blubber biopsies were collected on day one, just prior to hydrocortisone administration, and days three and five of hydrocortisone administration. We evaluated subsequent changes in several circulating stress hormones as well as cortisol and glucocorticoid metabolites in blubber and feces, respectively. There was a significant association between cortisol levels in serum and in blubber (F1,12.7 = 14.3, P < 0.01, mR2 = 0.57) despite substantial variability in blubber cortisol levels. Counterintuitively, fecal cortisol metabolite levels were inversely related to serum cortisol. The relationship between serum and blubber cortisol levels suggests blubber samples from remote sampling may be useful to detect stress loads in this species.

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Beneficial effect of hot spring bathing on stress levels in Japanese macaques

et al. 2018

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The ability of animals to survive dramatic climates depends on their physiology, morphology and behaviour, but is often influenced by the configuration of their habitat. Along with autonomic responses, thermoregulatory behaviours, including postural adjustments, social aggregation, and use of trees for shelter, help individuals maintain homeostasis across climate variations. Japanese macaques (Macaca fuscata) are the world's most northerly species of nonhuman primates and have adapted to extremely cold environments. Given that thermoregulatory stress can increase glucocorticoid concentrations in primates, we hypothesized that by using an available hot spring, Japanese macaques could gain protection against weather-induced cold stress during winter. We studied 12 adult female Japanese macaques living in Jigokudani Monkey Park, Japan, during the spring birth season (April to June) and winter mating season (October to December). We collected faecal samples for determination of faecal glucocorticoid (fGC) metabolite concentrations by enzyme immunoassay, as well as behavioural data to determine time spent in the hot springs, dominance rank, aggression rates, and affiliative behaviours. We used nonparametric statistics to examine seasonal changes in hot spring bathing, and the relationship between rank and air temperature on hot spring bathing. We used general linear mixed-effect models to examine factors impacting hormone concentrations. We found that Japanese macaques use hot spring bathing for thermoregulation during the winter. In the studied troop, the single hot spring is a restricted resource favoured by dominant females. High social rank had both costs and benefits: dominant females sustained high fGC levels, which were associated with high aggression rates in winter, but benefited by priority of access to the hot spring, which was associated with low fGC concentrations and therefore might help reduce energy expenditure and subsequent body heat loss. This unique habit of hot spring bathing by Japanese macaques illustrates how behavioural flexibility can help counter cold climate stress, with likely implications for reproduction and survival.

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Adrenal sensitivity to stress is maintained despite variation in baseline glucocorticoids in moulting seals

Cited by 25 publications

References 58 publications

Variation in adrenal and thyroid hormones with life-history stage in juvenile northern elephant seals (Mirounga angustirostris)

Variation in adrenal and thyroid hormones with life-history stage in juvenile northern elephant seals (Mirounga angustirostris)

Blubber cortisol qualitatively reflects circulating cortisol concentrations in bottlenose dolphins

Beneficial effect of hot spring bathing on stress levels in Japanese macaques

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