engleski

A DNA Repair Using The Alkaline Comet Assay in Human Peripheral Blood Lymphocytes After In vitro Exposure to 2 and 4 Gy of Gamma Radiation

Human population is not uniform in radiation sensitivity. The exposure of humans to low doses of ionizing radiation is still a great concern to occupational as well as environmental medicine. The alkaline comet assay determines single- and double-strand breaks as well as alkali labile sites in the DNA of single cells. To investigate the repair kinetics for gamma ray induced DNA damage following acute irradiation we exposed whole blood samples to 2 and 4 Gy. We used blood specimens from ten medical workers, all man, average age 39, 1 years (range: 23-59), and ten controls (occupationally non-exposed man) of average age 40, 5 years (range: 22-58). In each group there was four smokers and six non-smokers.The reduction of the tail length values at the different time intervals (immediately after exposure -„ zero time“ , 15, 30, 60 120 minutes and 24 hours in the case of 4 Gy) was measured. The radio induced damage and repair capacity were compared between groups by one-way ANOVA. For the post hoc-analyses Tukey HSD test for unequal N was used.The effect of an acute dose of 2 Gy is repaired 71, 84 % in control group and in exposed group 84, 46 % for 120 minutes. Twenty-four hours after dose of 4 Gy of gamma irradiation repair in controls were 96, 07 % and in exposed group 86, 59 %.

alkaline comet assay; gamma radiation; repair

Workshop 14: Exogenous and Endogenous Background Exposures to Carcinogens and Regulatory Consequences ; Poster Presentations S32-S89, P3: Risk Assessment ; doi:10.1016/j.toxlet.2008.06.570