Figure 7.

Hypoxia after lipopolysaccharide (LPS) exacerbates injury. Pulmonary artery endothelial cells (PAECs) were treated with 0.5 μg/mL LPS for 24 hours in a normoxic environment, after which time the medium was exchanged for LPS-free medium. Cells were then maintained another 24 hours in either normoxia or hypoxia, after which time caspase 3 activity (left) or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT; right) was measured. Relative to cells maintained in normoxia after LPS treatment, caspase 3 activity was increased and MTT was decreased in PAECs kept in a hypoxic environment. n values appear in the bars, and P values with symbols appear within the graphs.