Figure 3

Wistar rat lung tissue respiration, ATP content and caspase activity with and without 30 min prior incubation with glucose oxidase. Lung fragments were incubated at 37°C in 2.0 mL MEM with and without 200 μg glucose oxidase (which totally depleted O₂ from the solution) for 30 min. The samples were then rinsed with MEM and incubated at 37°C in 50 mL MEM (continuously gassed with 95% O₂: 5% CO₂) for up to ~7 h. At indicated time periods, samples were removed from the incubation medium and processed for measurements of O₂ consumption, ATP content and caspase activity. Panel A: Runs of cellular mitochondrial O₂ consumption are shown; t = 0 corresponds to animal sacrifice. The values of k _c (μM O₂ min^-1 mg^-1) are shown at the bottom of each run. Panel B: The values of k _c and ATP are plotted as a function of incubation time. Panel C: HPLC runs of caspase activity at 0, 3 and 6 h of incubation, showing only the AMC peak at ~4.8 min (solid lines, with GO; dotted lines, with GO). The substrate run (dashed line) was sample incubated without lung specimen for 6 h. Panel D: AMC peak areas are shown as a function of incubation period.