| Texto completo | |
| Autor(es): |
Titon, Braz
;
Barsotti, Adriana Maria Giorgi
;
Titon, Stefanny Christie Monteiro
;
Vaz, Renata Ibelli
;
de Figueiredo, Aymam Cobo
;
Vasconcelos-Teixeira, Ronyelle
;
Navas, Carlos A.
;
Gomes, Fernando Ribeiro
Número total de Autores: 8
|
| Tipo de documento: | Artigo Científico |
| Fonte: | General and Comparative Endocrinology; v. 354, p. 12-pg., 2024-04-27. |
| Resumo | |
Theoretical models predict that elevated androgen and glucocorticoid levels in males during the reproductive season promote immunosuppression. However, some studies report decreased stress response during this season. This study investigated annual variation in plasma corticosterone and testosterone levels, plasma bacterial killing ability (BKA), and neutrophil to lymphocyte ratio (NLR) in free-living male toads (Rhinella icterica). Toads were sampled in the field (baseline) and 1 h-post restraint over five months, and we considered the occurrence of vocal activity. Baseline corticosterone, testosterone, and BKA showed higher values during the reproductive period, specifically in calling male toads. The NLR was similar throughout the year, but higher values were observed in calling toads. Moreover, baseline NLR and BKA were positively correlated with both testosterone and corticosterone, suggesting higher steroid levels during reproduction are associated with enhanced cellular and humoral immunity. Despite fluctuation of baseline values, post-restraint corticosterone levels remained uniform over the year, indicating that toads reached similar maximum values throughout the year. Testosterone levels decreased following restraint before one specific reproductive period but increased in response to restraint during and after this period. Meanwhile, BKA decreased due to restraint only after the reproductive period, indicating immune protection and resilience to immunosuppression by stressors associated with steroid hormones during reproduction. Our results show that baseline and stress-induced hormonal and immune regulation varies throughout the year and are associated with vocal activity in R. icterica males, indicating a possible compromise between steroids and immune function in anuran males. (AU) | |
| Processo FAPESP: | 16/05024-3 - Estresse hídrico e resposta imune em sapos (Rhinella ornata) habitando fragmentos de Floresta Atlântica |
| Beneficiário: | Adriana Maria Giorgi Barsotti |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |
| Processo FAPESP: | 14/16320-7 - Impactos das mudanças climáticas e ambientais sobre a fauna: uma abordagem integrativa |
| Beneficiário: | Carlos Arturo Navas Iannini |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático |
| Processo FAPESP: | 16/01782-0 - Relações entre as condições ambientais e fisiológicas de atividade e sua importância para alterações da distribuição de sapos frente às mudanças climáticas |
| Beneficiário: | Braz Titon Junior |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |