DAMAGE AND REPAIR OF DNA IN URINARY-BLADDER EPITHELIUM OF RATS TREATED WITH N-BUTYL-N-(4-HYDROXYBUTYL)NITROSAMINE

  • 1 January 1977
    • journal article
    • research article
    • Vol. 68  (6) , 781-783
Abstract
N-Butyl-N-(4-hydroxybutyl)nitrosamine (BBN), which selectively induced urinary bladder tumors in several experimental animal species, caused damage of DNA in the bladder epithelium. Wistar rats were given 100 mg/kg of BBN intravesically and killed after 2, 6, 12, 24 or 48 h. DNA damage was examined by measuring the change in sedimentation pattern in an alkaline sucrose gradient. The amount of DNA in each fraction was determined by fluorescence spectrophotometry. At 2 h, the sedimentation profile shifted from heavier (no. 15, control peak) to lighter (no. 2 .apprx. 4) fractions, and the maximum effect appeared at 6 h as a single peak in the lighter fractions. At 12 h damaged DNA was in the process of repair as 2 peaks were present, 1 light and 1 heavy. At 48 h, the sedimentation profile showed a single peak identical with that of controls indicating complete repair of DNA.