Immunoendocrinology and Ecoimmunology in Brazilian Anurans

Integrative and Comparative Biology, Journal Year: 2022, Volume and Issue: 62(6), P. 1654 - 1670

Published: April 12, 2022

Abstract This paper reviews several aspects of immunoendocrinology and ecoimmunology in Brazilian species anurans under investigation for more than a decade, including (1) patterns annual covariation circulating steroids, calling behavior innate immunity, (2) endocrine immune correlates performance, (3) behavioral physiological parasite load, (4) thermal sensitivity function, (5) immunomodulation by experimental exposure to acute chronic stressors, as well manipulations simulated infections. Integrated results have shown an immunoprotective role increased steroid plasma levels during reproductive activity males. Moreover, higher helminth load is associated with changes traits field conditions. We also found anuran immunity generally characterized eurythermy, maximal performance observed temperatures close normal fever preferendum. the aerobic scope response decreased at Experimental stressors corticosterone redistribution, impact on function depending duration stress exposure. Interestingly, fate depends part individual body condition. Acute treatment enhances while prolonged immunosuppression. Still, hormonal are complex depend dose, treatment, variable considered. Finally, infection modulation expression cytokines, activation Hypothalamus-Pituitary-Interrenal axis, Hypothalamus-Pituitary-Gonadal reduced melatonin levels, suggesting that functional Immune-Pineal homologous previously described mammals. These integrated complementary approaches contributed better understanding mechanisms processes, ecological evolutionary implications immunoendocrinology.

Language: Английский

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Contrasting effects of transdermal and implant corticosterone treatments in the American bullfrog wound healing

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 378(1882)

Published: June 12, 2023

Glucocorticoid (GC) release is triggered by adverse stimuli that activate the hypothalamus-pituitary-adrenal/interrenal axis. Glucocorticoids may enhance or suppress immune functions depending on level of elevation. In this study, we investigated effects transient and chronic increase corticosterone (CORT) wound healing American bullfrog. Frogs were submitted to a daily transdermal hormonal application acutely elevated CORT plasma levels, vehicle as control. Other frogs surgically implanted with silastic tube filled resulted in elevation levels received empty implants A dermal biopsy was performed create photographed every 3 days. Individuals treated started faster than their control 32 days after biopsy. tended heal slower subjects. Plasma bacterial killing ability not affected treatment, which reinforces constitutive nature innate trait. By end experiment, from acute treatment had smaller wounds compared those receiving CORT-filled implants, highlighting differential (immunoenhancing) (immunosuppressive) levels. This article part theme issue ‘Amphibian immunity: stress, disease ecoimmunology’.

Language: Английский

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Stress and reproduction in amphibians

Elsevier eBooks, Journal Year: 2024, Volume and Issue: unknown, P. 121 - 150

Published: Jan. 1, 2024

Language: Английский

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Introduction to the special issue Amphibian immunity: stress, disease and ecoimmunology

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 378(1882)

Published: June 12, 2023

Amphibian populations have been declining worldwide, with global climate changes and infectious diseases being among the primary causes of this scenario. Infectious are drivers amphibian declines, including ranavirosis chytridiomycosis, which gained more attention lately. While some led to extinction, others disease-resistant. Although host's immune system plays a major role in disease resistance, little is known about mechanisms underlying resistance host–pathogen interactions. As ectotherms, amphibians directly subjected temperature rainfall, modulate stress-related physiology, immunity pathogen physiology associated diseases. In sense, contexts stress, ecoimmunology essential for better understanding immunity. This issue brings details ontogeny system, crucial aspects innate adaptive how can influence resistance. addition, papers demonstrate an integrated view stress on immune–endocrine The collective body research presented herein provide valuable insights into outcomes natural populations, particularly context changing environmental conditions. These findings may ultimately enhance our ability forecast effective conservation strategies populations. article part theme ‘Amphibian immunity: ecoimmunology’.

Language: Английский

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Temperature Extreme Events Decrease Endocrine and Immune Reactive Scope in Bullfrogs (Lithobates catesbeianus)

Integrative and Comparative Biology, Journal Year: 2022, Volume and Issue: 62(6), P. 1671 - 1682

Published: June 30, 2022

Abstract Currently, effects of increased atmospheric temperature, in the context ongoing climate change, have been investigated multiple organisms and levels biological organization. While there has a focus on impacts mean an emergent equally important point is consequences recurrent exposure to extreme temperature events, simulating heat waves. This study serial high temperatures immune endocrine variables before after acute secondary stressor bullfrogs (Lithobates catesbeianus). Adult males were divided into three groups subjected thermal regimes: control (c; constant 22°C); experimental 1 (E1; kept at 22°C exposed 4 days 30°C every 16 days); 2 (E2; 6 days). Blood samples collected last day key events. Two weeks event, animals restraint stress (1 h) sampled again. used determine neutrophil: lymphocyte ratio, plasma bacterial killing ability, as well as, corticosterone testosterone levels. Overall, we found events did not affect over time. Meanwhile, previous modulated responsiveness restraint. The amplitude ratio response decreased with number exposures These results suggest that climatic hidden bullfrog's response, expressed diminished reactive scope novel stressor. represents highly deleterious facet change since prevents proper coping wildlife challenges.

Language: Английский

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Testosterone immunomodulation in free-living and captive Rhinella icterica male toads

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 378(1882)

Published: June 12, 2023

Testosterone (T) regulates immune function, with both immunostimulatory and immunosuppressive effects on several vertebrates. We investigated the covariation between plasma T corticosterone (CORT) levels immunity (plasma bacterial killing ability (BKA), neutrophil to lymphocyte ratio (NLR)) in free-living

Language: Английский

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The Impacts of Transdermal Application of Corticosterone on Toad (Rhinella icterica) Immunity

Integrative and Comparative Biology, Journal Year: 2022, Volume and Issue: 62(6), P. 1640 - 1653

Published: July 28, 2022

Abstract Recent studies have shown that acute physiological increases in endogenous glucocorticoid levels immunostimulatory effects. Although post-acute stress immunosuppressive effects also been described, the difference between enhancing and suppressing immune response seems mediated by stressor's duration, intensity, component under analysis. To elicit physiologically relevant corticosterone can be found Rhinella icterica toads after stressful events (e.g., restraint or captivity) understand how increased of different intensities affect testosterone plasma parameters (in vitro bacterial killing ability, neutrophil-to-lymphocyte ratio, vivo phagocytosis peritoneal leukocytes), we submitted to transdermal application two doses (1 10 μg). Corticosterone with intensities: 3 times for 1 μg fourteen μg, compared vehicle, ratio regardless dose. However, there was no effect on ability. Interestingly, both promoted immunosuppression, decreasing leukocytes' activity 60% receiving dose 1µg 40% those μg. Our results show complexity relationship immunomodulation. The distinct magnitudes levels, less intense increase generating greater cell-mediated immunosuppression. Future using achieve compare vs. pharmacological hormone are imperative understanding these interrelationships response.

Language: Английский

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Dehydration followed by restraint sustains high circulating corticosterone and improves immunity in toads

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology, Journal Year: 2024, Volume and Issue: 296, P. 111683 - 111683

Published: June 21, 2024

Language: Английский

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Baseline and stress-induced changes in plasma bacterial killing ability against gram-negative bacteria are partially mediated by the complement system in Rhinella diptycha toads

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology, Journal Year: 2024, Volume and Issue: 297, P. 111701 - 111701

Published: July 17, 2024

Language: Английский

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