Figure 4.

Shc isoform expression in the severely fibrotic baboon BPD model. Animals delivered at 140 days' gestation (gestational control, GC) and exposed to 100% oxygen for 10 days were infused with 5 mg/kg of either anti– bombesin-like peptide antibody (2A11) or nonimmune isotype-matched IgG (MOPC-21). 2A11 treatment clinically and pathologically attenuates BPD. Samples were equilibrated by total protein content, then analyzed by Shc Western analysis (A) and densitometry (C). Baboon lungs treated with MOPC-21 demonstrated 4.8-fold higher p66^Shc expression relative to gestational control lungs; this difference approached statistical significance (p = 0.059). In contrast, 2A11 treatment increased p52^Shc by sixfold, p46^Shc by sevenfold, and p66^Shc by tenfold (*p < 0.003 for all) relative to MOPC-21 control lungs, suggesting isoform-specific regulation (p = 0.0073). Glyceraldehyde phosphate dehydrogenase (GAPDH) reprobe of the Shc blot (B) confirmed equivalent total protein loading.