Fusarium proliferatum-fermented corn stimulates development of placental glutathione S-transferase-positive altered hepatic foci in female rats
Lebepe-Mazur, S.; Wilson, T.; Hendrich, S.
Veterinary and Human Toxicology 37(1): 55-59
1995
ISSN/ISBN: 0145-6296 PMID: 7709594 Document Number: 450363
Groups of 6-wk-old female Sprague Dawley rats (n=8) were initiated with 30 mg diethylnitrosamine (DEN)/kg. Control and initiated groups were fed a semi-purified diet or diets supplemented with F. proliferatum-contaminated maize containing 20 or 50 mg fumonisin B1 (FB1)/kg. Histochemical staining for gamma -glutamyltransferase (GGT) and immunochemical staining for placental glutathione S-transferase (PGST), markers of altered hepatic foci (AHF), were performed on serial frozen hepatic sections. gamma -Glutamyltransferase-(+) AHF were not found in any group. Dosing with DEN significantly increased the number of PGST-(+) hepatocytes compared with the uninitiated groups. Groups fed F. proliferatum diets also had a significantly increased number of PGST-(+) AHF compared with those fed F. proliferatum-free diets. The volume percentage of liver occupied by PGST-(+) foci was significantly greater in the groups treated with DEN or F proliferatum. The number of PGST-(+) AHF/liver in the groups given DEN was also significantly greater than in the uninitiated groups. F. proliferatum exposure also significantly increased the number of PGST-(+) AHF/liver. It is concluded that feeding F. proliferatum containing 20 mg/kg FB1 promotes the development of DEN-initiated AHF in rats and that placental glutathione S-transferase is a more useful marker than GGT in detecting AHF produced by small amounts of fumonisins fed after initiating dosing with DEN.