Calcium dependence of bleb formation and cell death in hepatocytes

Calcium dependence of bleb formation and cell death was evaluated in rat hepatocytes following ATP depletion by metabolic inhibition with KCN and iodoacetate (‘chemical hypoxia’). Cytosolic free Ca 2+ was measured in single cells by ratio imaging of Fura-2 fluorescence using multiparameter digitized video microscopy. Cells formed surface blebs within 10 to 20 minutes after chemical hypoxia and most cells lost viability within an hour. An increase of cytosolic free Ca 2+ was not required for bleb formation to occur. One to a few minutes prior to the onset of cell death, free Ca 2+ increased rapidly in high Ca 2+ buffer (1.2 mM) but not in low Ca 2+ buffer (