Meeting Abstract

P2-40  Monday, Jan. 5 15:30  Interplay between acclimation temperature and immune challenge on energy expenditure and immune response in the precocial rodent Octodon degus RAMIREZ-OTAROLA, N.N.*; ESPINOZA, J.; KALERGIS, A.M.; SABAT, P.; Lab. of Animal Ecophysiol., Univ. of Chile, Santiago; MIII, Pont. Cathol. Univ. of Chile, Santiago; MIII, Pont. Cathol. Univ. of Chile, Santiago; Lab. of Animal Ecophysiol., Univ. of Chile, Santiago nat.rotarola@gmail.com

We examined the influence of thermal conditions experienced at an early age on the immune response and the energetic costs associated in the precocial rodent, Octodon degus. Pups were acclimated to either warm or cold conditions (15 ° C or 30 ° C), from birth to weaning (day 30). Following the acclimation period, pups were randomly injected with lipopolysaccharide (LPS) or pyrogen-free saline. Samples of blood and measures of metabolic rate (BMR) were obtained 24h before and after the immune challenges. Individuals acclimated at 15 ° C and injected with pyrogen-free saline presented the lowest levels of Interleukin-1β (IL-1β), while the levels of Il-1β in individuals acclimated at 15 ° C and treated with LPS were similar to the individuals acclimated at 30 ° C and injected with LPS or pyrogen-free saline. Pups acclimated at 15° C and injected with LPS exhibited the lowest body temperature. Also, we did not find a significant effect of the interaction between ambient temperature and immune challenge on BMR. However, individuals challenged with LPS showed the highest BMR and the lowest body mass among treatments. We concluded that thermal conditions experienced at an early stage influence some aspects of the immune response in pups of Octodon degus. Nevertheless, ambient temperature at this developmental stage does not seem to affect energy expenditure associated to this response. Financial support Beneficio Apoyo de Tesis Doctoral CONICYT N°21110063 to NRO