Deuterium oxide protects against hyperthermic cell death: evidence for role of interfacial water

Tissue culture cells incubated at 43 degrees C show a dramatic decrease in cell survival compared with cells incubated at lower temperatures; the effect is termed hyperthermic cell death (HCD). Replacing water in the culture medium with deuterium oxide produces a dose-dependent reduction in HCD. On the basis of this and other evidence it is concluded that the mechanism of HCD involves a hydration-dependent phase transition in membrane lipids.