| Abstrakt: |
The sensitivity to the lethal effect of gamma-rays, cis- and trans-diamminedichloroplatinum (DDP), cis- and trans-iminoethers of DDP (IE) was compared in two groups of E. coli--K12 and B. In all experiments, cells of wild types appeared to be most resistant to these agents. gamma-Resistant and gamma-sensitivity/hypersensitive strains occupy an intermediate position according to their sensitivity to cis-DDP derivatives. In almost all the cases, both single and especially double mutants defective for the systems of nucleotide excision repair, recombination repair, and inducible SOS-repair are most sensitive to DDP derivatives. The data obtained show that in E. coli the repair of lethal lesions after cis-DDP action is more complicated than after gamma-irradiation. Of DDP derivatives cis-DDP is most effective, while trans-DDP is less effective, and cis- and trans-IE are considerably less effective, respectively. It is shown that the effects of ionizing radiation in low doses (more than 10 different regimes), or of treatment with cis-DDP in low concentrations do not change the survival of E. coli after their respective effects in high doses. In other words, under the effect of ionizing radiation and cis-DDP no adaptive response for the lethal action was found in E. coli. |
