Influence of low environmental temperature on inflammation in bullfrog (Rana catesbeiana): qualitative and quantitative evaluation

Abstract

Objectives of this study were to investigate the influence of low environmental temperature on the experimentally induced inflammatory response in post-metamorphic Rana catesbeiana (bullfrogs). To accomplish these goals, 120 specimens of Rana catesbeiana were kept at 6ºC and 24ºC, and treated by transfixion of thigh muscular tissue with a 5-0 suture or IM carrageenan injection. Results obtained through qualitative and quantitative evaluations showed that the lower environmental temperature significantly modulates the inflammatory process development. The animals in both models that were kept at 6ºC showed a significantly lower number of inflammatory cells in the lesion site than the one verified at 24ºC, apart from the evolution time. On the other hand, any factor related to the host mechanism of defense ought not to be blocked by the temperature, since the area of reaction to the injury showed to be equivalent in most of the studied time.