[Simultaneous effect of 5-bromodeoxyuridine and cysteamine on x-irradiated diploid cells of Chinese hamster, Cricetulus griseus, in vitro].

Cells of the Chinese hamster line B 14 FAF 28 were treated with BUdR and irradiated with X-rays under the presence of cysteamine. The dose-dependent inactivation rates could be determined rather precisely by marking single cells. Daily cell counts in the growing colonies made it possible to establish individual colony growth curves. The results of both analyses show for untreated and treated cells a nearly equal factor with respect to the protecting effect of cysteamine. Also in the "macrocolonies" this effect is clearly measurable even five days after irradiation indicating a still existing very different vitality of the cells at that time. The results are discussed with concern to following irradiations.