title: ACTH modulation on corticosterone, melatonin, testosterone and innate immune response in the tree frog Hypsiboas faber.
abstract: 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.
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, 05508-900 São Paulo, SP, Brazil. Electronic address: adriana33@gmail.com.
authors.forename: Adriana Maria Giorgi
authors.initials: AMG
authors.lastname: Barsotti
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, 05508-900 São Paulo, SP, Brazil.
authors.forename: Vania Regina
authors.initials: VR
authors.lastname: de Assis
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, 05508-900 São Paulo, SP, Brazil.
authors.forename: Stefanny Christie Monteiro
authors.initials: SCM
authors.lastname: Titon
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, 05508-900 São Paulo, SP, Brazil.
authors.forename: Braz
authors.initials: B
authors.lastname: Titon
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, 05508-900 São Paulo, SP, Brazil.
authors.forename: Zulma Felisbina
authors.initials: ZF
authors.lastname: da Silva Ferreira
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, 05508-900 São Paulo, SP, Brazil.
authors.forename: Fernando Ribeiro
authors.initials: FR
authors.lastname: Gomes
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001001:Anura / Q000276:immunology / Q000378:metabolism*; D003345:Corticosterone / Q000097:blood*; D007113:Immunity, Innate / Q000187:drug effects*; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D000324:Adrenocorticotropic Hormone; D008550:Melatonin; D003345:Corticosterone
keywords: ACTH; Corticosterone; Immunocompetence; Melatonin; Stress; Testosterone