Correlation between age and DNA damage detected by FADU in human peripheral blood lymphocytes

Abstract

Fluorometric analysi of DNA unwinding (FADU) is a fast and reliable method for detecting single strand DNA breaks as an index of DNA damage induced by clastogenic agents. A study of damage detected by FADU was conducted on DNA extracted from peripheral blood lymphocytes of 128 healthy nonsmoking regular donors (ranging in age from 19 to 67 years) and from 5 umbilical cord blood samples. DNA damage was measured as percentage of unwound DNA after alkalinization. Statistical analyses, both parametric (Pearson r correlation coefficient, b regression coefficient, ANOVA) and nonparametric (Kruskal-Wallis H test, Spearman r_s rank correlation coefficient) support a significant correlation between age of donors and amount of DNA damage. The same results are found when adult donors are divided in four age classes and ANOVA test performed among the mean percentages of unwound DNA of each class. Furthermore, donors of the same age belonging to different blood groups (A, B. AB and O) do not show any difference in DNA damage detected by FADU.