Fig. 4.

Cytoplasmic phospholipase A₂ enzyme activity in cultured astrocytes and neurons following H₂O₂ exposure: embryonic hippocampal neurons and astrocytes in culture were treated with H₂O₂ and assessed for cPLA₂ activation using an enzyme activity assay. cPLA₂ enzyme activity normalized to untreated cells in cultured A. astrocytes and B. neurons. C. cPLA₂ enzyme activity normalized to untreated cells in cultured astrocytes following exposure to physiologically relevant concentrations of H₂O₂. H₂O₂ concentrations were determined by the levels of H₂O₂ produced by whole brain mitochondria isolated from reproductively incompetent female mice. D. Levels of cPLA₂ enzyme activation in astrocytes and neurons (nmol/min/ml/mg of protein).