AJP - Regulatory, Integrative and Comparative Physiology, Vol 241, Issue 3 198-R202, Copyright © 1981 by American Physiological Society
Pyrogens fail to produce fever in a cordylid lizard
H. P. Laburn, D. Mitchell, E. Kenedi and G. N. Louw
We investigated the effects on body temperature of the lizard Cordylus
cataphractus of intracardiac injections of leucocyte pyrogen (LP)
synthesized from rabbit blood and of killed Aeromonas hydrophila, a
gram-negative bacterium reputed to be pathogenic in lizards. Lizards were
placed in a photothermal gradient that allowed them to select a preferred
body temperature following the injections. Neither injection of 0.5 ml
rabbit LP nor of 4 X 10(9) organisms of A. hydrophila in 0.2 ml sterile
saline caused body temperature of lizards to differ from that of control
lizards injected with sterile saline. Following injection of these
solutions in the lizards placed in a thermal gradient where ambient
temperature ranged from 20-88 degrees C, body temperature was maintained
between 32 and 34 degrees C. Pyrogens failed to elevate body temperature
even when body temperature was elevated artificially to 36 degrees C before
injection. We conclude that C. cataphractus does not respond with fever to
either rabbit LP or A. hydrophila. Fever may not be ubiquitous even among
lizards.
