SELECTIVE LOSS OF NEUROFILAMENT PROTEINS AFTER EXPOSURE OF DIFFERENTIATED HUMAN IMR-32 NEUROBLASTOMA-CELLS TO OXIDATIVE STRESS

Millimolar concentrations of ascorbate in the presence of iron can cau se neuronal cell death. This study shows that the human neuronal cell line IMR-32 is sensitive to ascorbate and that cytotoxicity can be blo cked by the antioxidant enzymes Cu/Zn-superoxide dismutase and catalas e. There was a selective loss of neurofilament proteins after exposure to 5 or 10 mM ascorbate, as assessed by immunostaining and by Western blotting. Loss of actin or tubulin was not seen, suggesting that loss of neurofilaments is a sensitive and selective marker for free radica l damage in these cells.