Tj. Walters et al., HSP70 EXPRESSION IN THE CNS IN RESPONSE TO EXERCISE AND HEAT-STRESS IN RATS, Journal of applied physiology, 84(4), 1998, pp. 1269-1277
We have previously documented the regional distribution of 70-kDa heat
shock protein (HSP70) in brains of rats made hyperthermic by brief ex
posure to high-powered microwaves (HPM; 2.06 GHz). We now compare HSP7
0 expression induced by HPM exposure to that induced by exertional and
/or environmental heat stress. Rats were chronically implanted with a
temperature probe guide in the hypothalamic region of the brain (T-br)
After recovery, the following treatment groups were examined: HPM; sh
am exposed; treadmill exercise at room temperature (24 degrees C; Ex-1
); treadmill exercise in a warm environment (34 degrees C; Ex-2); and
sedentary groups (Sed-1 and Sed-2), in which ambient temperature was a
djusted so that the T-br mimicked the T-br in the corresponding exerci
se groups. Significant HSP70 expression occurred only in the hyperther
mic (Ex-2, Sed-2, and HPM) groups. The pattern of HSP70 expression was
similar among Ex-2 and Sed-2 rats but differed from that in HPM rats.
We conclude that 1) the pattern of HSP70 expression differs between H
PM and non-microwave heating, and 2) exercise alone was not sufficient
to induce central HSP70 expression.