Fig. 2.

Lungs of mice exposed to intraperitoneal bleomycin have increased expression of HIF1-α and HIF2-α within the vascular endothelium. A: representative images of immunohistochemical staining for HIF1-α and HIF2-α in wild-type mice given vehicle (PBS) vs. intraperitoneal bleomycin. Scale bars: 50 μm at ×60 magnification. Arrows point to immunostain positive cells. B: confocal IF images from lung sections of bleomycin-treated mice for HIF1-α or HIF2-α (green), endothelial cell marker CD34 (red), and DAPI (blue). Magnification ×100. C: In vehicle (PBS)-treated lungs, immunostaining for pimonidazole was not detected, while after bleomycin was administered, immunostaining for pimonidazole was noted in multiple cell populations in the lung parenchyma, including alveolar epithelium (arrow in panel at 1 wk) and vascular endothelium (arrow in panel at 33 days). Scale bars: 50 μm at × 60 magnification. Counterstains with methyl green.