Fig. 2.

Antioxidant enzymatic activities in response to ceramide augmentation in the lung and modulation by caspase inhibitors. Lung SOD activity levels measured 24 h after intratracheal dihydroceramide (control; white bar) or ceramide (Cer) instillation (1 mg/kg) without (black bar) or with Z-Asp-CH2-DCB (3 mg/kg ip daily ×2; gray bar). SOD activity was measured in lung lysates after fractionation into cytosolic (A) and mitochondrial components (B), respectively, followed by normalization by protein concentration (means + SE; *P < 0.05 vs. control). C: catalase activity levels in the mouse lung measured 24 h after intratracheal dihydroceramide (control; n = 3) or ceramide (Cer; n = 4) instillation (1 mg/kg) without (black bar) or with Z-Asp-CH2-DCB (3 mg/kg ip daily ×2; gray bar). Results were expressed as mean fold change compared with control (dotted line) +SE.