HEAT PROTECTION BY DEUTERIUM-OXIDE OF HEAT-SENSITIVE AND WILD-TYPE CHINESE-HAMSTER OVARY CELLS

The ability of deuterium oxide (D2O) to protect a heat-sensitive and t hermotolerance-impaired Chinese hamster ovary (CHO) mutant cell line, HS-36 (Harvey and Bedford 1988), from heat killing was examined and co mpared to the parent CHO 10B cell line (WT). Both non-thermotolerant ( NT) and thermotolerant (TT) G1 populations were examined. D2O differen tially protected the NT cell lines from heat killing, with thermal pro tection ratios (D0) of 2.5 and 4.3 for HS-36 and WT cells. respectivel y. D2O provided additional protection to TT cells, but now protected t he TT HS-36 cells more than the TT WT cells when the thermal protectio n ratios of TT cells are compared with those of NT cells (1.15 versus 0.82). The differential protection from heat of the mutant and wild-ty pe lines by D2O may be useful in studies of induced lesions in protein aceous cellular systems (e.g. the nuclear matrix, cytoskeleton and pla sma membrane) using these two paired cell lines.