[Carminomycin induction of single-stranded DNA breaks in the normal and tumorous cells of mice administered the antibiotic intravenously].

The effect of carminomycin administered intravenously to albino mice on the sedimentation character of the ascitic cell DNA of mouse lymphadenosis NK/Li, as well as the cells of the lungs, kidneys, liver, heart and spleen in alkaline sucrose gradients was studied. It was found that carminomycin in a dose of 3.5 mg/kg (LD50) induced DNA single-strand breaks in the cells of the lungs, kidneys, liver and heart. At the same time the single-strand breaks were not detected in the tumor cells NK/Li and the cells of the spleen. The results are indicative of correlation between sensitivity of the cells to carminomycin and a decreased capacity of the antibiotic for induction of single-strand breaks in DNA. Probably, the cell ability for DNA repair is an important factor defining the antitumor selective effect of carminomycin. Induction of the single-strand breaks reflects the role of the excision repair in healing the damages induced by carminomycin.