Behavioural thermoregulatory responses to malaria infection and interleukin-1 beta in rats

1. Behavioural thermoregulation was assessed by the ambient temperatures se lected by rats moving freely around an enclosed temperature gradient circui t (15 to 32 degrees C). 2. Interleukin-1 beta (10 mu g/kg i.p.) increased both colonic and selected ambient temperatures, but malaria (Plasmodium berghei) had no effect on ei ther temperature, although malarial rats responded to interleukin-lp with p yrexia. 3. Immune status of lymph and spleen cells appeared unaltered by malaria in rats. 4. These data indicate that malarial rats do not have a pyrogenic drive to develop fever. (C) 2000 Elsevier Science Ltd. All rights reserved.