Fever and Behavioural Temperature Regulation in the FrogRana esculenta

Publisher Website
Google Scholar
Abstract
The skin and colonic temperatures were recorded in frogs(Rana esculenta)which had selected a suitable microenvironment in a box filled with 2–3 cm water. The water temperatures ranged from 0°C to + 40°C. Such measurements were performed before and after intraperitoneal injections of killed pathogenic bacteria (M. xenopiandM. ranae), killed non‐pathogenic bacteria (M. aquae II) and 0.9% sterile saline, intraperitoneal injections of blood plasma from frogs pre‐injected with killedM. ranae, injections of PGE, into the brain. The injections of pathogenic bacterial endotoxin caused, after latencies of 5–120 min, higher preferred water temperatures, which produced an average maximum colonic temperature increase of 6.5°C ± 1.0°C (S.E.) (p< 0.001). The non‐pathogenic bacteria and sterile saline caused no temperature change. Monophasic hyperthermia of shorter latency was caused by injections of blood plasma from frogs pre‐injected withM. ranae.Monophasic hyperthermia of the shortest latency was observed after diencephalic injections of PGE1. Based on their similarity we suggest that ectothermic and endothermic fever have a common phylogenetic origin.