Significance of lysosomal proteases; cathepsins B and H in maxillary mucosa and nasal polyp with non-atopic chronic inflammation.

Tissue extracts from maxillary mucosa (MM) and nasal polyp (NP) with non-atopic chronic inflammation were applied to DEAE-Sepharose, and hydrolytic activity of lysosomal proteases (cathepsins B and H) was measured by the fluorometric assay. Hydrolytic activity of cathepsins B and H in MM, of which cathepsin B was a major one, was about 3.5 times as high as that in NP. Protein composition resembled in both extracts except for several apparent protein bands with high molecular weight observed in NP. These results suggest that in MM with chronic inflammation, mucosal destruction induced by excess lysosomal granuloproteases overwhelming protease inhibitors would occur, being much related to the formation of its irreversible lesion.