Correlation between DNA damage and GST-P in hepatocytes of juvenile rats treated with diethylnitrosamine

We investigated the relationship between DNA damage detected as single strand breaks using a Comet assay and the expression of glutathione S-transferase P-form (GST-P) as a marker of the early stage of carcinogenesis. In this study, 4-week-old rats were exposed to 10 or 40 ppm diethylnitrosamine (DEN) in drinking water for 14 days, then both DNA damage and GST-P expression were evaluated in the three primary lobes [left (L), right median (RM) and right anterior (RA)] of the liver to clarify the correlation between two endpoints within the organ over time.Both DNA damage and GST-P expression increased almost in parallel in a dose- and time-dependent manner in all lobes, and those had a good relationship with heterogeneous response, L≥RM>RA. Therefore, it was confirmed that the result of the Comet assay could correspond to the histopathological changes appearing in the initiation stage in rat hepatocytes.