ORTHOVANADATE INDUCES CELL-DEATH IN RAT DENTATE GYRUS PRIMARY CULTURE

THE aim of this study was to define the effects of a potent inhibitor of tyrosine phosphatases, sodium orthovanadate (0.1-100 mu M for up to 48 h), on dentate gyrus cells (DGC) in culture. Treatment with 100 mu M orthovanadate evoked a delayed form of cell death. To examine the p ossible involvement of apoptosis in orthovanadate-induced cell death, biochemical and morphological alterations were compared with those of necrotic death induced by sodium azide. Phase-contrast microscopy and nuclear condensation analysis showed that orthovanadate and azide each evoked cell death by distinct pathways. TUNEL assay was positive in b oth cases. Application of a protein synthesis inhibitor, cycloheximide , did not prevent cytotoxicity caused by either orthovanadate or azide and potentiated the effects of vanadate. We conclude that orthovanada te-induced death of DGC bears features of apoptosis.