Changes in Repair of Potentially Lethal Damage with Culture Age in EMT6 Cells

Publisher Website
Google Scholar
Abstract
The changes in the amplitude of repair of potentially lethal damage (PLD) were investigated in EMT6 [mouse mammary tumor] cells with increasing culture age and the delay necessary to achieve this repair was determined. This experimental system presents all intermediaries between the exponential growth type and a plateau with a cell turnover nearly nil. The radiosensitivity was studied by the colony method. When the percentage of surviving cells was tested immediately after irradiation it was observed that their radiosensitivity increased with culture age. This percentage fell only slightly when the cells were tested for viability 6 h after irradiation. Therefore, the amplitude of repair increases with culture age. Repair terminated 1, 1.75, 3 and 6 h after irradiation of cultures aged, respectively, 2, 4, 6 and 9 days. The delay and amplitude of repair did not vary significantly for cultures of 9, 11 and 13 days.