Survival and Concanavalin-A-Induced Capping in CHO Fibroblasts after Exposure to Hyperthermia, Ethanol, and X Irradiation

Abstract

Two parameters, concanavalin-A-induced capping and clonogenicity, were examined in HA-1 fibroblasts after exposure to heat, ethanol, x irradiation, and heat plus deuterium oxide. Capping and clonogenicity were shown to decrease over time in samples exposed to 43, 44, and 45/sup 0/C, while both parameters remained unaffected at 37, 41, and 42/sup 0/C. Ethanol exposure showed a survival decrease at a concentration of 8% but no significant effect on survival at 4, 6, and 7%. Capping, however, decreased over time at ethanol concentrations of 6, 7, and 8%. X irradiation had no effect on capping over a dose range of 0 to 1400 rad, while survival was markedly decreased. At 37/sup 0/C, exposure to 20, 40, and 80% deuterium oxide showed no effect on either survival or capping. However, at 43/sup 0/C, the same concentrations of deuterium oxide markedly increased both capping and clonogenicity over that of cells exposed to 43/sup 0/C without deuterium oxide. Potential mechanisms accounting for the heat- and ethanol-induced impairment of capping ability are inhibition of cellular energy metabolism and/or alteration of plasma membrane composition.