Captivity effects on immune response and steroid plasma levels of a Brazilian toad (Rhinella schneideri). Issue 2 (28th June 2017)

• Record Type: Journal Article
• Authors: Titon, Stefanny Christie Monteiro; Assis, Vania Regina; Titon Junior, Braz; Cassettari, Bruna de Oliveira; Fernandes, Pedro Augusto Carlos Magno; Gomes, Fernando Ribeiro
• Is Part Of: Journal of experimental zoology. Volume 327:Issue 2/3(2017)
• Page Start: 127
• Page End: 138
• Publication Date: 2017-06-28
• Subjects: Zoology -- Periodicals; Zoology; Animal Population Groups -- physiology; Zoology; Electronic journals; Periodical; Periodicals; 590
• DOI: 10.1002/jez.2078
• Languages: English
• ISSNs: 2471-5646

Abstract

GRAPHICAL ABSTRACT: Toads maintain high corticosterone, while body condition and testosterone gradually fall during prolonged time in captivity. Phagocytic percentage of macrophages and neutrophils decay over time, also associated with decreasing testosterone plasma levels. Abstract: Stressors can increase plasma glucocorticoid (GC) levels and decrease plasma androgen levels in different species of vertebrates. GCs can have immune‐enhancing or immunosuppressive effects, which are dependent upon stress duration and intensity. The worldwide decline in amphibian populations is strongly linked to an array of different stressors. The impacts of stress on GCs, androgens, and the immune response are important to clarify and should lead to the better development of conservation strategies. The present study in adult male toads of Rhinella schneideri investigated the effects of captivity (7, 30, and 60 days) on plasma corticosterone (CORT) and plasma testosterone (T), as well as innate immune responses, specifically humoral and cell mediated responses, as indicated by bacterial killing ability (BKA) and phagocytosis by peritoneal cells, respectively. Captivity increased CORT threefold and decreased T versus controls. CORT maintained a threefold elevation throughout the captivity period, while body mass and T gradually decreased with time in captivity. BKA was lower at day 30, versus days 7 and 60, while peritoneal cell phagocytic efficiency decreased after day 30, remaining low at day 60. Moreover, phagocytosis efficiency was positively associated with T and body condition, suggesting that the effects of chronic stress on reproductive potential and immune response might be associated with the state of energetic reserves.