CYTOTOXIC AND GENOTOXIC EFFECTS OF 5 N-ALKANALS IN PRIMARY CULTURES OF RAT AND HUMAN HEPATOCYTES

Five n-alkanals were examined for cytotoxicity, as evaluated by the tr ypan blue exclusion test, and for genotoxicity, as evaluated by the in duction of unscheduled DNA synthesis (UDS), in primary cultures of rat and human hepatocytes. After 20 h exposure, cytotoxicity was similar in cells of the two species, and increased with the length of the carb on chain. In rat hepatocytes, propanal (10-100 mM), butanal (10-100 mM ), pentanal (3-30 mM) and hexanal (3-30 mM) induced a modest but signi ficant and dose-dependent increase of net nuclear grain counts, while in human hepatocytes this effect was not detected. Nonanal (3-30 mM), which showed the highest cytotoxic effect, failed to induce UDS in bot h cell types. These results seem to suggest that at the concentrations which are presumably attained after ingestion with food or generated by lipid peroxidation processes the five n-alkanals tested are presuma bly unable to induce genotoxic effects in the human liver.