THE EFFECT OF HYPERTHERMIC TREATMENT ON ELECTROENCEPHALOGRAPHIC RECOVERY AFTER INTERRUPTION OF RESPIRATION IN RATS

Electroencephalography (EEG) was utilized for investigating the effect of hyperthermia followed by apneic hypoxia in rats. They were heated whole-bodily to 41 degrees C for 15 min under the control of an artifi cial rodent ventilator, after drug-induced generalized paralysis. A tr anscutaneous oxygen saturation monitor was applied to detect the hypox ic condition. EEG was monitored with bipolar needle electrodes. The 72 -kDa heat-shock protein (HSP72) in brain was analyzed by sodium dodecy l sulfate-polyacrylamide electrophoresis, followed by immunostaining w ith an anti-HSP72 antibody. There was no difference in the time interv al from onset of apneic hypoxia to flat EEG between the hyperthermic a nd control groups, but cortical electrical activity appeared earlier i n the hyperthermia group than the control group, after 90 s of ventila tion interruption. The cardiac function did not change in the two grou ps. The HSP72 synthesis significantly increased in the brain of the ra ts with hyperthermic treatment.