Species and sex differences of aflatoxin B1-induced glutathione S-transferase placental form in single hepatocytes.

Abstract Species and sex differences of aflatoxin B 1 (AFB 1 )-induced glutathione S-transferase placental form (GST-P) positive single hepatocytes have been investigated 48 h after an intraperitoneal injection of AFB 1 to young male and female Fischer rats (2 mg AFB 1 /kg body wt) and male Syrian golden hamsters (6 mg AFB 1 /kg body wt). The presence of GST-P positive hepatocytes was examined by the immunohistochemical method. Male rats formed three times as many AFB 1 -induced GST-P positive hepatocytes as females. Pretreatment of both male and female rats with an inhibitor of GSH synthesis, buthionine sulfoximine (BSO) (4 mmol/kg body wt), 2 h and 4 h before AFB 1 injection increased AFB 1 -induced GST-P positive hepatocytes by about 120% above the controls. Male hamsters formed several-fold less AFB 1 -induced GST-P positive hepatocytes than male rats. Pretreatment with BSO did not increase AFB 1 -induced GST-P positive hepatocytes in hamsters even though it produced an increase in hepatic necrosis. It appears that GSH and GSH S-transferases play an important role in modulating hepatic AFB 1 -DNA binding and AFB 1 -induced GST-P positive hepatocytes in rats and hamsters.