THE EFFECTS OF A PURIFIED DIET ON SISTER CHROMATID EXCHANGE FREQUENCIES AND MITOTIC-ACTIVITY IN ADULT-RAT HEPATOCYTES

When female Fischer 344 rats were fed a commercial diet (Purina Rodent Laboratory Chow 5010) the background sister chromatid exchange (SCE) level in hepatocytes significantly increased with time, whereas feeding a purified diet (TEKLAD TD 81050) led to no significant changes in the SCE frequency. These results are consistent with the hypothesis that the dietary intake of mutagens/carcinogens causes an 'age-dependent' increase in hepatocyte SCE frequency. However, the high level of SCE found at the beginning of the experiment appears also to result from factors that are independent of the diet. Possible explanations include the relatively long cell cycle in hepatocytes and their sensitivity to lipid peroxidation products.