Behavioral and physiological responses to intraperitoneal injection of zymosan in chicks

• Published in: Domestic animal endocrinology 2020-07, Vol.72, p.106471-106471, Article 106471
• Main Authors: Tachibana, T., Nakatani, A., Islam Khan, M.S., Makino, R., Cline, M.A.
• Format: Article
• Language: English
• Subjects: Chick; Cloacal temperature; Corticosterone; Feeding; Zymosan
• ISSN: 0739-7240; 1879-0054
• DOI: 10.1016/j.domaniend.2020.106471

Zymosan is a cell wall component of the yeast Saccharomyces cerevisiae and produces severe inflammatory responses in mammals. When zymosan is peripherally injected in mammals, it induces several behavioral and physiological changes including anorexia and hyperthermia. However, to our knowledge, behavioral and physiological responses to zymosan have not yet been clarified in birds. Therefore, the purpose of the present study was to determine if intraperitoneal injection of zymosan affects food intake, voluntary activity, cloacal temperature, plasma corticosterone (CORT) and glucose concentrations, and splenic gene expression of cytokines in chicks (Gallus gallus). Intraperitoneal injection of zymosan (2.5 mg) significantly decreased food intake, voluntary activity, and plasma glucose concentration, and increased plasma CORT concentration. The injection of 0.5 mg zymosan significantly increased cloacal temperature, while 2.5 mg zymosan had a tendency to increase it. Finally, 2.5 mg zymosan significantly increased the splenic gene expression of interleukin-1β (IL-1β), IL-6, IL-8, interferon-γ, and tumor necrosis factor–like cytokine 1A. The present results suggest that zymosan would be one of components which induces nonspecific symptoms including anorexia, hypoactivity, hyperthermia, and stress responses, under fungus infection in chicks. •Intraperitoneal injection of zymosan decreased food intake and voluntary activity in chicks.•Zymosan induced hyperthermia.•Zymosan decreased plasma glucose level while it increased plasma corticosterone level.•Zymosan induced mRNA expression of cytokines in the spleen.•Zymosan induces nonspecific symptoms including anorexia, hypoactivity, hyperthermia, and stress responses in chicks.