Fig. 6. Hyperosmotic cell shrinkage results in activation of caspase 3. (A) Normalized MCVs of D54-MG cells were recorded following the addition of 150 or 300 mOsm mannitol in the presence or absence of 2 mM glutamine. Data are the mean results from three independent experiments. Error bars represent s.e.m. with n=10,000-20,000 cells. (B) Caspase 3 activity, as measured by luminescence, in cells exposed to isosmotic (300 mOsm) or hyperosmotic (337.5-600 mOsm) bath solutions for 24 hours. Activity normalized to 300 mOsm exposure. Data are from three experiments. Error bars represent s.e.m. and n=3 samples per experiment. ^*P<0.05.