Repeated adrenocorticotropic hormone administration alters adrenal and thyroid hormones in free-ranging elephant seals

McCormley, Molly; Champagne, Cory D.; Deyarmin, Jared; Stephan, Alicia; Crocker, Daniel E.; Houser, Dorian S.; Khudyakov, Jane

doi:10.1093/conphys/coy040

Cited by 16 publications

(37 citation statements)

References 82 publications

(130 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Baseline sample collection was conducted as previously described ( Deyarmin et al , 2019 , McCormley et al , 2018 ) during September to November of 2017 at Año Nuevo State Reserve, San Mateo County, CA, USA. This period is generally a short haul out and is not associated with extensive fasting, molting or reproduction.…”

Section: Methodsmentioning

confidence: 99%

“…Serum cortisol, total T3 (tT3) and reverse T3 (rT3) were measured in duplicate using radioimmunoassays (RIAs; cortisol: cat# 07221102, tT3: cat # 0613254215, both from MP Biomedicals, USA; rT3: cat # 38-RT3HU-R125, Alpco, USA), which were previously validated for use in northern elephant seals ( Ensminger et al , 2014 , Khudyakov et al , 2017 ). Aldosterone was measured in duplicate using an enzyme-linked immunosorbent assay (cat# 11-ALDHU-E0, lot # 172040; Alpco, USA) previously validated for use in elephant seals ( McCormley et al , 2018 ). Mean intra-assay CVs were <2.5% for all hormone assays.…”

Section: Methodsmentioning

confidence: 99%

“…Commonly used markers, such as circulating GCs, are extremely variable and do not fully capture the complexity of the physiological response ( MacDougall-Shackleton et al , 2019 , Romero et al , 2019). For example, marine mammal responses to various stressors can be associated with significant elevation of the mineralocorticoid aldosterone and decrease in thyroid hormone levels ( Champagne et al , 2018 , DeRango et al , 2019a , DeRango et al , 2019b , McCormley et al , 2018 , St Aubin et al , 1992 ). Furthermore, circulating hormone measurements are not practical for many marine mammal species because they are difficult to access for blood sampling (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…As marine mammal blubber is vertically stratified by fatty acid composition, cellular morphology, rate of lipid accumulation and mobilization and gene expression ( Ball et al , 2017 , Guerrero et al , 2017 , Struntz et al , 2004 ), the impacts of stress hormones are likely to be more pronounced in the inner, more metabolically active layer of blubber. We previously identified a cluster of genes that were differentially expressed in inner blubber in response to acute and repeated HPA axis stimulation in a model marine mammal, the northern elephant seal ( Mirounga angustirostris ; Deyarmin et al , 2019 , McCormley et al, 2018 , Khudyakov et al , 2017 ). These included upregulated genes encoding metabolic and antioxidant enzymes (long-chain-fatty-acid CoA ligase 1, ACSL1 ; hydroxymethylglutaryl-CoA synthase 2, HMGCS2 ; cysteine dioxygenase 1, CDO1 ; E3-SUMO-protein ligase PIAS4, PIAS4 ; glutathione peroxidase 3, GPX3 ; microsomal glutathione S-transferase 1, MGST1 ), adipokines (adiponectin, ADIPOQ ; leptin, LEP ), pro-adipogenic factors (dickkopf-related protein 1, DKK1 ; zinc-alpha-2-glycoprotein 1, AZGP1 ), lipid droplet proteins (perilipin 1, PLIN1 ; cell death activator CIDE-A, CIDEA ) and other metabolism-regulating proteins (glycine receptor subunit alpha-2, GLRA2 ), and a gene associated with extracellular matrix remodeling (transforming growth factor beta-induced, TGFBI ), which was downregulated ( Deyarmin et al ., 2019 ).…”

Section: Introductionmentioning

confidence: 99%

“…These included upregulated genes encoding metabolic and antioxidant enzymes (long-chain-fatty-acid CoA ligase 1, ACSL1 ; hydroxymethylglutaryl-CoA synthase 2, HMGCS2 ; cysteine dioxygenase 1, CDO1 ; E3-SUMO-protein ligase PIAS4, PIAS4 ; glutathione peroxidase 3, GPX3 ; microsomal glutathione S-transferase 1, MGST1 ), adipokines (adiponectin, ADIPOQ ; leptin, LEP ), pro-adipogenic factors (dickkopf-related protein 1, DKK1 ; zinc-alpha-2-glycoprotein 1, AZGP1 ), lipid droplet proteins (perilipin 1, PLIN1 ; cell death activator CIDE-A, CIDEA ) and other metabolism-regulating proteins (glycine receptor subunit alpha-2, GLRA2 ), and a gene associated with extracellular matrix remodeling (transforming growth factor beta-induced, TGFBI ), which was downregulated ( Deyarmin et al ., 2019 ). Gene expression changes were correlated with other markers, including increase in cortisol, aldosterone and reverse triiodothyronine (rT3) levels and decrease in total triiodothyronine (tT3) levels ( McCormley et al , 2018 ).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A blubber gene expression index for evaluating stress in marine mammals

Busqueta

Crocker

Champagne

et al. 2020

Conservation Physiology

Self Cite

View full text Add to dashboard Cite

Evaluating the impacts of anthropogenic disturbance on free-ranging marine mammal populations, many of which are in decline, requires robust diagnostic markers of physiological stress and health. However, circulating levels of canonical ‘stress hormones’ such as glucocorticoids, which are commonly used to evaluate animal health, do not capture the complexity of species-specific responses and cannot be easily measured in large, fully aquatic marine mammals. Alternatively, expression of stress-responsive genes in hormone target tissues such as blubber, the specialized subcutaneous adipose tissue that can be manually or remotely sampled from many marine mammals, may be a more informative and sensitive indicator of recent (within 24 h) exposure to stressors. We previously identified genes that were upregulated in the inner blubber of juvenile northern elephant seals during experimental stimulation of the hypothalamic–pituitary–adrenal axis. In this study, we measured baseline expression levels of a subset of these genes in inner blubber of unmanipulated juvenile elephant seals of varying physiological states and correlated them with other stress markers (body condition index, corticosteroid and thyroid hormone levels). Expression of 10 genes, including those associated with lipid metabolism (ACSL1, HMGCS2, CDO1), redox homeostasis (GPX3), adipokine signaling (ADIPOQ), lipid droplet formation (PLIN1, CIDEA) and adipogenesis (DKK1, AZGP1, TGFBI), was described by three principal components and was associated with cortisol and thyroid hormone levels. Significantly, baseline gene expression levels were predictive of circulating hormone levels, suggesting that these markers may be potential indicators of exposure to stressors in marine mammal species that are inaccessible for blood sampling. A similar approach may be used to identify species-specific stress markers in other tissues that can be sampled by remote biopsy dart from free-ranging marine mammals, such as outer blubber and skin.

show abstract

Section: Methodsmentioning

confidence: 99%