The modulation exerted by glucocorticoids in physiological responses to stressors is essential for maintaining short-term homeostasis. However, highly frequent and/or prolonged activation of the hypothalamic-pituitary-adrenal/interrenal axis may inhibit processes that are important to long-term fitness and health, including reproduction and immunocompetence. The present study evaluates the response to adrenocorticotropic hormone (ACTH) injection in the adult male tree frog, Hypsiboas faber, as indicated by levels of plasma corticosterone (CORT), plasma testosterone (T), ocular melatonin (MEL), hematocrit and immune functioning (total leukocyte count and bacterial killing ability against Escherichia coli). All levels were measured 1, 3 and 6h after treatment. ACTH increased CORT levels whilst decreasing T and MEL levels at 1h post-treatment. 6h after ACTH injection, hematocrit and MEL levels increased. ACTH treatment did not significantly modulate the immune measures over the time-range sampled. The hormonal changes observed in response to ACTH treatment suggest that stressors could act as inhibitors of reproductive activity, as well as differentially modulating melatonin levels at different time-points.
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http://dx.doi.org/10.1016/j.cbpa.2016.12.002 | DOI Listing |
Aquat Toxicol
January 2025
Programa de Pós-Graduação em Biologia Animal, Centro de Biociências, Universidade Federal de Pernambuco, Av. Professor Moraes Rego, S/N - Cidade Universitária, Recife 50670-420, Brazil; Aquatic Ecotoxicology Laboratory, Centro de Biociências, Departamento de Zoologia, Universidade Federal de Pernambuco, Av. Professor Moraes Rego, S/N - Cidade Universitária, Recife 50670-420, Brazil. Electronic address:
Phenanthrene is considered a priority polycyclic aromatic hydrocarbon due to its ubiquitous presence in aquatic and terrestrial environments and its toxic potential. Tadpoles are sensitive ecotoxicological models that provide important information regarding effects of contaminants in amphibian species. The goal of the present study was to generate information regarding the acute and chronic toxicity of phenanthrene to the neotropical tree frog Dendropsophus branneri early life stages.
View Article and Find Full Text PDFEcol Evol
January 2025
Conservation Science Research Group, School of Environmental and Life Sciences University of Newcastle Callaghan New South Wales Australia.
Amphibians are among the most threatened vertebrate taxa globally. Their global decline necessitates effective conservation actions to bolster populations across both the larval and adult stages. Constructing man-made ponds is one action proven to enhance reproduction in pond-breeding amphibians.
View Article and Find Full Text PDFToxicon
January 2025
Universidade Estadual do Oeste do Paraná, Programa de Pós-Graduação em Biociências e Saúde (PPG-BCS), Cascavel, Brazil.
This study investigated the effects of a novel bombesin-related peptide (BR-b), derived from the skin of the Chaco tree frog (Boana raniceps), on glucose homeostasis in non-obese and hypothalamic-obese male rats. Hypothalamic obesity was induced in neonatal rats through high-dose administration of monosodium glutamate (MSG; 4 g/kg), while control animals (CTL) received an equimolar saline solution. At 70 days of age, both MSG and CTL groups underwent an oral glucose tolerance test (OGTT; 2 g/kg) with or without prior intraperitoneal administration of BR-b at doses of 0.
View Article and Find Full Text PDFInt J Parasitol Parasites Wildl
April 2025
Department of Biology, University of New Mexico, Albuquerque, NM, USA.
A new genus and a new species of isosporoid coccidium (Apicomplexa: Conoidasida: Eimeriorina) are described and illustrated from green tree frogs () (Anura: Hylidae) imported from Papua New Guinea and Indonesia. The described species has disporocystic and tetrasporozoic oocysts without a Stieda body. Nine species originally belonging to the genus Schneider, 1881 in the family Eimeriidae Minchin, 1903 described from Anura are recognized as members of the new genus and new combinations of the species names are proposed.
View Article and Find Full Text PDFMicrobiol Spectr
December 2024
College of Ecology, Lishui University, Lishui, Zhejiang, China.
Unlabelled: and are recognized as significant opportunistic pathogens affecting aquatic animals and humans. However, their infections in amphibians are poorly documented, and their pathogenicity to the Chinese spiny frog () remains unexplored. This study investigated an outbreak of putrid-skin disease among on a farm in Lishui City, Zhejiang Province, China.
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