Hyperthermic toxicity and the modulation of heat damage to cell protein synthesis in HeLa cells.

That some of the effects of hyperthermia on HeLa cell protein synthesis may involve free radical activity is suggested by experiments with free radical scavengers. A possible source of damaging free radicals induced by heat may lie in peroxidative events within lipid-containing membranes. These can be blocked by EGTA. Other experiments with t-butylhydroperoxide indicate that cycloheximide can also neutralise peroxidative effects. These effects are discussed in the light of observations that calcium depletion (or EGTA treatment) can induce thermotolerance and that cycloheximide does not prevent the development of thermotolerance.