Plasma leves of corticosterone, testosterone and immunocompetence in Bufonids.

• Grant number: 11/10560-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): September 01, 2011
• Effective date (End): July 30, 2015
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Fernando Ribeiro Gomes
• Grantee: Vania Regina de Assis
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 14/05806-6 - Effects of acute stress of movement restriction, transdermal application of corticosterone and subcutaneous testosterone implant on immunocompetence and plasma levels of corticosterone and testosterone on the cane toad (Rhinella marina), BE.EP.DR

Abstract

Several lines of evidence have emphasized the importance of the ability of the immune response as part of the evolution of various aspects of the life history of animals, and chronically elevated plasma levels of corticosteroids and androgens have been identified as immunosuppressants. The objective of this study is to understand the interrelationships between levels of corticosterone (CORT), testosterone (T) and immunocompetence in Bufonids seeking to verify if the experimental elevation of steroid hormones have an immunosuppressive effect, as well as if the elevation of each they interfere in plasma levels of the other. Since preliminary studies indicate the existence of interspecific variation in levels of steroids and immunosuppressive effects, a comparative approach will be used for three species of Bufonids, which differ in geographical distribution and susceptibility to deforestation: Rhinella ornata, R. icterica and R. schneideri. The hypotheses to be tested are: 1) In natural environment, the basal levels of CORT and T should vary in the following order: R. ornata> R. icterica> R. schneideri, while the immune response should vary in the following order: R. schneideri> R. icterica> R. ornata, 2) after experimental restraint stress, all species have elevated baseline levels of CORT, decreased T and reduced immune response, but the post-stress levels of CORT should vary in the following order: R. ornata> R. icterica> R. schneideri, while levels of T and immunocompetence should vary in the following order: R. schneideri> R. icterica> R. ornata; 3) Animals treated with chronic transdermal administration of CORT have lower immune response and lower plasma levels of T, when compared to animals Placebo and control groups, and the effect of treatment on T levels and immunocompetence should vary in following order: R. schneideri> R. icterica> R. ornata, 4) animals chronically treated with transdermal administration of T have lower immunocompetence and lower plasma levels of CORT compared with animals Placebo and control groups, and the effect of treatment on plasma levels of CORT and immunocompetence should vary in the following order: R. schneideri> R. icterica> R. ornata.

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ASSIS, VANIA REGINA; MONTEIRO TITON, STEFANNY CHRISTIE; GOMES, FERNANDO RIBEIRO. Acute stress, steroid plasma levels, and innate immunity in Brazilian toads. General and Comparative Endocrinology, v. 273, n. SI, p. 86-97, MAR 1 2019. (11/10560-8, 13/00900-1)

GIORGI BARSOTTI, ADRIANA MARIA; DE ASSIS, VANIA REGINA; MONTEIRO TITON, STEFANNY CHRISTIE; TITON JUNIOR, BRAZ; DA SILVA FERREIRA, ZULMA FELISBINA; GOMES, FERNANDO RIBEIRO. ACTH modulation on corticosterone, melatonin, testosterone and innate immune response in the tree frog Hypsiboas faber. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY, v. 204, p. 177-184, FEB 2017. (11/10560-8, 13/00900-1)

DE ASSIS, VANIA REGINA; MONTEIRO TITON, STEFANNY CHRISTIE; GIORGI BARSOTTI, ADRIANA MARIA; TITON, JR., BRAZ; GOMES, FERNANDO RIBEIRO. Effects of Acute Restraint Stress, Prolonged Captivity Stress and Transdermal Corticosterone Application on Immunocompetence and Plasma Levels of Corticosterone on the Cururu Toad (Rhinella icterica). PLoS One, v. 10, n. 4, APR 1 2015. (11/10560-8, 13/00900-1)

MONTEIRO TITON, STEFANNY CHRISTIE; TITON JR, BRAZ; GIORGI BARSOTTI, ADRIANA MARIA; GOMES, FERNANDO RIBEIRO; ASSIS, VANIA REGINA. Time-related immunomodulation by stressors and corticosterone transdermal application in toads. PLoS One, v. 14, n. 9, SEP 20 2019. (14/16320-7, 11/10560-8, 16/05024-3)

ASSIS, VANIA REGINA; MONTEIRO TITON, STEFANNY CHRISTIE; TEIXEIRA QUEIROZ-HAZARBASSANOV, NICOLLE GILDA; MASSOCO, CRISTINA DE OLIVEIRA; GOMES, FERNANDO RIBEIRO. Corticosterone transdermal application in toads (Rhinella icterica): Effects on cellular and humoral immunity and steroid plasma levels. JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL GENETICS AND PHYSIOLOGY, v. 327, n. 4, p. 200-213, APR 2017. (11/10560-8, 13/00900-1)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

ASSIS, Vania Regina de. Plasma levels of corticosterone, testosterone and immunocompetence in Bufonids. 2015. Doctoral Thesis - Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) São Paulo.