Abstract
In comparison to chromosomal breakage (CB) studies, sister chromatid exchange (SCE) is considered a more sensitive indicator of chromosomal damage. The present study answers the question as to whether or not methylazoxymethanol acetate (MAM AC) exerts an effect on chromosomal breakage and sister chromatid exchange in short-term human leucocyte cultures derived from the same individuals. Only chromatid breaks were observed in a total 1168 metaphases. Statistical analyses of the data have indicated that there were no significant differences in the incidence of chromatid breaks when cultures treated with MAM AC were compared to control cultures (p>.2). However, an examination of 1020 metaphases derived from BrdU treated cultures from the same individuals revealed a significant increase in SCE with MAM AC exposure. Therefore, MAM AC has no effect on the incidence of CB, and SCE is a more sensitive indicator of chromosomal damage than CB is in this system.
