OXIDANT-INDUCED INHIBITION OF DNA-SYNTHESIS

The DNA synthesis inhibitory effect of hydrogen peroxide is more pronounced when treatments are performed at 37-degrees-C than at 4-degrees-C and in low density rather than high density cultures. Recovery from DNA synthesis inhibition appears to be rapid in cells challenged with the oxidant at 4-degrees-C, whereas no recovery (for up to 6 hours) was apparent in cells treated at 37-degrees-C. These results correlate well with our previous data, indicating that different types of lesions are produced by hydrogen peroxide at the two different temperatures, and suggest an explanation for the lower toxicity elicited by the oxidant at 4-degrees-C, as compared to the physiological temperature of 37-degrees-C.