Heat protection by sugars and sugar analogues

We have examined the relative ability of 16 sugars and sugar analogues to reduce cell killing by hyperthermia of 40 min, 45°C. In general, sugars were added to the culture medium 6 h prior to heating at a concentration of 100 mM (400 mosmol). The results show that D-hexoses, L-hexoses, methylated or thiolated sugars and disaccharides significantly protected cells against thermal damage, increasing survival by factors of 10 to 100. The degree of protection varied for specific sugars and could not be predicted on the basis of sugar conformation or the number of hydroxyl groups. Relative heat protection was partially dependent on the survival assay technique (pre-and post-plating); consistently lower cell survival was measured when cells were subcultured after hyperthermia, both in medium-control and sugar-protected cells. However, the time dependence of heat protection appeared independent of pre-and post-plating.Cell survival after heating was not increased by two sugars: (a) D-idose, and (b) 2-deoxy-D-gal...