FED BEFORE DIETHYLNITROSAMINE, FUSARIUM-MONILIFORME AND F-PROLIFERATUM MYCOTOXINS ALTER THE PERSISTENCE OF PLACENTAL GLUTATHIONE S-TRANSFERASE-POSITIVE HEPATOCYTES IN RATS

Groups of 5-w-old F344/N female rats were fed a semipurified diet for 13 w with or without 20 mg fumonisin B-1/kg provided from an aqueous e xtract of Fusarium moniliforme-corn culture. After 1 w, a single dose of 30 mg diethylnitrosamine (DEN)/kg was given orally. Twelve weeks la ter, the presence of placental glutathione S-transferase-positive (PGS T-[+]) hepatocytes were immunohistochemically quantified. Rats given D EN and the FB1-containing diet for 1 or 13 w developed 4-fold more PGS T-[+] hepatocytes than rats given DEN alone. In a second study, male a nd female F344/N rats were fed 20 mg purified FB1/kg diet or F prolife ratum-corn culture material containing 20 mg FB1/kg diet for 1 w befor e DEN treatment. One week after DEN treatment, male rats fed the F pro liferatum-corn culture material had significantly fewer PGST-[+] hepat ocytes than those fed DEN with or without purified FB1. At 9 w after D EN treatment, PGST-[+] cells in female rats given DEN and fed F prolif eratum-corn culture material were more persistent than in rats given D EN alone. Males given DEN and fed FB1 or F proliferatum culture materi al had significantly fewer PGST-[+] hepatocytes than males given DEN a lone. These results suggest that F moniliforme and F proliferatum comp onents are cocarcinogens males however, FB1 and unidentified F prolife ratum components reduced the persistence