Journal of Applied Physiology, Vol 44, Issue 3 438-445, Copyright © 1978 by American Physiological Society
Temperature and corticosterone relationships in microwave-exposed rats
W. G. Lotz and S. M. Michaelson
Plasma corticosterone and colonic temperature were measured in
unanesthetized male rats exposed to 2,450-MHz continuous wave (cw)
radiation to characterize the response of the pituitary-adrenal axis to
microwave exposure. The rats were exposed in the far field of a horn
antenna for 30 or 60 min at power densities of 0, 13, 20, 30, 40, 50, or 60
mW/cm2, or for 120 min at 0, 13, 20, 30, or 40 mW/cm2. The average energy
absorption rate of the rats was 0.16 W/kg absorbed per mW/cm2 incident.
Plasma from individual rats decapitated immediately after exposure was
collected for analysis. Colonic temperature was significantly elevataed
after exposures to power densities of 13 mW/cm2 or greater, with
progressively larger increases after high intensity exposures. Plasma
corticosterone was significantly elevated above control levels only after
exposures at 50 or 60 mW/cm2 for 30- or 60-min exposures, and at 20, 30,
and 40 mW/cm2 for 120-min exposures. The relationship between the increased
levels of circulating corticosterone and colonic temperature suggested that
the increases in corticosterone levels may reflect a level of physiological
response to the body temperature elevations caused by microwave exposure.
