Main sites of immunohistochemical staining for proteoglycans and collagens in normal and fibrotic rat lungs.
| Region | CSPG | Versican | Biglycan | Decorin | Collagen I |
| Normal rat lung | |||||
| Airways | |||||
| Epithelium | − | − | + | + | − |
| Amina propria | ++ | ++ | − | − | ++ |
| Submucosa | ++ | − | − | + | ++ |
| Vessels | |||||
| Endothelium | − | − | − | − | − |
| Lamina propria | + | ++ | − | + | + |
| Media | + | + | ++ | − | + |
| Adventitia | ++ | − | + | ++ | ++ |
| Alveolar Walls | |||||
| Extracellular | ++ | + | − | − | + |
| Intracellular | − | − | − | − | − |
| Changes associated with bleomycin-induced pulmonary fibrosis in rat | Increased extracellular staining in fibrotic foci | Increased extracellular staining in fibrotic foci | Weak intracellular staining (PII, AM) | Weak intracellular staining (PII, AM) | Increased extracellular staining |
−: no staining
+: weak staining
++: prominent staining
CSPG: Chondroikinsulphate proteoglycan
PII: alveolar type II pneumocytes
AM: alveolar macrophages