Lung tissue respiration, ATP content and caspase activity in Wistar rats anesthetized with sevoflurane (S) or urethane (U). Lung fragments were 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
(μM O2 min-1 mg-1) are shown at the bottom of each run. Panel B: The values of k
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. The Rt for Ac-DEVD-AMC was ~2.5 min and AMC ~4.8 min (insert). The substrate run (dashed line) was without lung specimen at 6 h. Panel D: AMC peak areas are shown as a function of incubation period.