EFFECTS OF OCHRATOXIN A ON CYTOTOXICITY AND CELL DIFFERENTIATION IN CULTURED RAT EMBRYONIC CELLS

In the present study, the effects of ochratoxin A (OTA) on cytotoxicity, cell differentiation, and other cell functions in the embryonic midbrain cells, which are dopaminergic, were compared to those in the limb bud cells, which are nondopaminergic, to assess the selectivity of OTA central action. Twelve-day rat embryo midbrain and limb bud cells were cultured in Dulbecco's modified Eagle's medium nutrient and Ham's F12 (1:1) mixture containing 10% Nuserum for 96 h in the presence of various concentrations of OTA. OTA significantly reduced the levels of protein, DNA and glutathione, and [3H]thymidine incorporation into DNA in both embryonic midbrain and limb bud cells in a similar concentration-dependent manner. The IC50 values for cytotoxicity measured by neutral red uptake were 1.10 µ M in the midbrain cells and 1.05 µ M in the limb bud cells. The IC50 values of cell differentiation were 1.10 µ M in the midbrain cells and 1.0 µM in the limb bud cells. The addition of exogenous glutathione (32.5 µ M) did...