Comparative aspects of vertebrate adrenals

Norris, David O.; Carr, James A.

doi:10.1016/b978-0-12-820093-3.00009-5

Cited by 6 publications

(12 citation statements)

References 49 publications

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“…Stress evolved in vertebrates as an adaptive endocrine response that increases survival, helping individuals cope with noxious stimuli or stressors (M€ ostl & Palme, 2002;Pacak & Palkovits, 2001). Stressors activate the hypothalamic-pituitary-adrenocortical axis (HPA), resulting in the release of GC into the bloodstream (Hadley & Levine, 2007;Norris, 2006). The main role of GC in mammals is the control of energy homeostasis (Roldan & Herzig, 2015).…”

Section: Introductionmentioning

confidence: 99%

Faecal cortisol levels in a wild Iberian red deer population are best explained by prior weather conditions

Gort‐Esteve,

Carbajal,

López

et al. 2024

Journal of Zoology

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The responsiveness of the hypothalamic–pituitary‐adrenocortical axis to stressors is crucial for wild animals to survive and adapt to environmental changes without compromising individual welfare. We analysed the influence of prior weather conditions, seasonality, the influx of ecotourism, and nutrition on stress levels in a wild population of red deer in a Mediterranean hunting reserve in the Pre‐Pyrenees, Spain. We used faecal cortisol metabolites as a proxy for physiological and psychological stress, and faecal triiodothyronine metabolites as an indicator of nutritional stress. Faecal analyses were chosen because it is a non‐invasive technique that does not alter an individual's behaviour, and it is easy to conduct in a wild population, something which presents added challenges due to the lack of a controlled environment. Our results indicate that prior weather conditions, rather than just seasonality, best explained the variations in these hormones within seasons and among years. On the contrary, the results showed that high levels of the cortisol hormone did not necessarily correspond to low levels of the triiodothyronine hormone. This could be a sign of acute nutritional stress in this population. Finally, we did not find an effect of the ecotourism influx on cortisol levels, suggesting that this deer population tolerates the presence of tourists.

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Section: Introductionmentioning

confidence: 99%

Faecal cortisol levels in a wild Iberian red deer population are best explained by prior weather conditions

Gort‐Esteve,

Carbajal,

López

et al. 2024

Journal of Zoology

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“…Progesterone elevations can occur in advance of implantation owing to the secretions of the corpus luteum (CL), a temporary endocrine structure formed from the ruptured ovarian follicle following ovulation. The CL secretes P4 to prepare the uterine lining for the implantation of a blastocyst [12], and continues to secrete P4 during early pregnancy prior to development of the placenta. High tissue P4 values have been associated with ovulation in cetaceans [50,53,76], with sequential ovulations and concurrent P4 elevation for 86 and 103 days, respectively, in captive odontocetes [77].…”

Section: Discussionmentioning

confidence: 99%

“…Recent studies have used endocrine markers of various tissues to study health, stress and reproductive rates of baleen whales ( [1,[5][6][7][8][9][10], reviewed in [11]). Endocrine systems regulate body processes via negative feedback loops involving steroid hormones, which ultimately control reproductive processes such as maturation, oestrous and ovulation, pregnancy and seasonal mating behaviour [12]. For example, the female steroid hormone progesterone is produced at high concentrations during pregnancy and is a known proxy for gestation [13,14].…”

Section: Introductionmentioning

confidence: 99%

Prolonged baleen hormone cycles suggest atypical reproductive endocrinology of female bowhead whales

et al. 2023

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Serial measurements of hormone concentrations along baleen plates allow for reconstructions of mysticete whale reproductive histories. We assessed gestation and calving interval in bowhead whales ( Balaena mysticetus ) by measuring progesterone, oestradiol, corticosterone and nitrogen stable isotope ratios (δ 15 N) along baleen of 10 females from the eastern Canada-west Greenland population. Three immature females (body size < 14.32 m) had uniformly low progesterone concentrations across their baleen, while seven mature females (body size ≥ 14.35 m) had repeated, sustained elevations of progesterone indicative of pregnancies. The mean duration of progesterone elevations (23.6 ± 1.50 months) was considerably longer than the approximately 14 month gestation previously estimated for this species. We consider several possible explanations for this observation, including delayed implantation or sequential ovulations prior to gestation, strategies that would allow females to maximize their fitness in variable Arctic conditions, as well as suggest modified criteria defining gestation as a shorter component of the entire progesterone peak. Calving intervals varied within and among individuals (mean = 3.7 years; range = range 2.8–5.7 years), providing population-specific reproductive estimates for growth models used in bowhead whale management and conservation.

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“…The neurohypophysis in teleosts consists of fiber bundles protruding dorsally into the larger adenohypophysis ( 17 , 18 ). Adenohypophyseal cells are arranged in distinct subregions [rostral lactotropes and corticotropes; intermediate somatotropes, thyrotropes, gonadotropes; caudal melanotropes and corticotropes ( 19 – 21 )].…”

Section: Introductionmentioning

confidence: 99%

Altered glucocorticoid reactivity and behavioral phenotype in rx3-/- larval zebrafish

2023

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IntroductionThe transcription factor rx3 is important for the formation of the pituitary and parts of the hypothalamus. Mutant animals lacking rx3 function have been well characterized in developmental studies, but relatively little is known about their behavioral phenotypes.MethodsWe used cell type staining to reveal differences in stress axis architecture, and performed cortisol measurements and behavior analysis to study both hormonal and behavioral stress responses in rx3 mutants.Results and DiscussionConsistent with the role of rx3 in hypothalamus and pituitary development, we show a distinct loss of corticotrope cells involved in stress regulation, severe reduction of pituitary innervation by hypothalamic cells, and lack of stress-induced cortisol release in rx3 mutants. Interestingly, despite these deficits, we report that rx3-/- larval zebrafish can still display nominal behavioral responses to both stressful and non-stressful stimuli. However, unlike wildtypes, mutants lacking proper pituitary-interrenal function do not show enhanced behavioral performance under moderate stress level, supporting the view that corticotroph cells are not required for behavioral responses to some types of stressful stimuli but modulate subtle behavioral adjustments under moderate stress.

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Comparative aspects of vertebrate adrenals

Cited by 6 publications

References 49 publications

Faecal cortisol levels in a wild Iberian red deer population are best explained by prior weather conditions

Faecal cortisol levels in a wild Iberian red deer population are best explained by prior weather conditions

Prolonged baleen hormone cycles suggest atypical reproductive endocrinology of female bowhead whales

Altered glucocorticoid reactivity and behavioral phenotype in rx3-/- larval zebrafish

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