[Action of carminomycin on the structural integrity, primary damage susceptibility and postradiation regeneration of the DNA from Erhlich's ascitic carcinoma].

Carminomycin added to the cell culture of Ehrlichs ascites carcinoma (EAC) induced single breaks in DNA whose number increased proportionally to the amount of the antibiotic and the incubation time with it (up to 1 hour). The relationship between the incubation time and DNA injury is first of all defined by the necessity for the antibiotic metabolic activation or the properties of endonucleases. No increase in the number of one-thread breaks during the incubation period of 60 to 120 minutes indicated a possible reparation of DNA injury induced by the antibiotic in the late periods. The exposure of the EAC cells to carminomycin before gamma-irradiation did not result in any increase in the primary radiation injury to DNA but suppressed DNA postradiation reparation.