Survival response of asynchronous and synchronous Chinese hamster cells exposed to fluorescent light following 5-bromodeoxyuridine incorporation

Abstract

Flourescent light illumination of 5-bromodeoxyuridine-substituted Chinese hamster cells results in an exponential decrease in survival. The slope of the resulting survival curves is dependent on the percentage of thymine replaced by bromouracil in DNA. The lack of shoulder on the survival curves suggests that the cells are unable to repair sublethal damage. This is further supported by the lack of recovery in split-dose experiments. The age-response pattern of the cells is essentially flat and this is discussed relative to the lack of capacity for sublethal damage. Cysteamine protects 5-bromodeoxyuridine-substituted cells against fluorescent light killing with a dose-modification factor of 2.1.