title: The relationship between proteases activity and glycoprotein levels in middle ear effusions from experimental otitis media in cats.
abstract: The relationship between lysosomal proteases activity (elastase and cathepsin B) and levels of mucous glycoproteins in middle ear effusions (MEEs) was studied using a cat model of otitis media with effusion (OME) induced by Eustachian tube obstruction (ETO). The ratio of cathepsin B activity to total protein concentration (TPC) in MEE was 25.6 +/- 19.4 RFU/g x dl-1 at 1 week after ETO, and increased with the duration of OME. The ratio of elastase activity to TPC had a significant correlation to total leukocyte count. The ratio of fucose levels to TPC, which is one of the parameters reflecting levels of mucous glycoprotein, at 1 week after ETO was significantly higher than that at both 2 and 4 weeks after ETO. The percentage of glycoprotein levels absorbed to wheat germ lectin was highest at 1 week after ETO, and decreased with the duration of OME. In conclusion, mucous glycoproteins in cat occupy a larger portion of glycoproteins in MEE at the early stage of OME, and elastase and other lysosomal proteases may play a role in both stimulation of mucin release from goblet cells and mucin degradation. The balance of these processes seems to be a key factor determining mucin levels in MEEs.
authors.affiliation: Department of Otorhinolaryngology, Mie University School of Medicine, Tsu, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hamaguchi
authors.forename: K
authors.initials: K
authors.lastname: Takeuchi
authors.forename: C S
authors.initials: CS
authors.lastname: Jin
authors.forename: Y
authors.initials: Y
authors.lastname: Majima
authors.forename: H
authors.initials: H
authors.lastname: Suzumura
authors.forename: Y
authors.initials: Y
authors.lastname: Sakakura
authors.forename: S K
authors.initials: SK
authors.lastname: Juhn
mesh_terms: D000418:Albumins / Q000032:analysis; D000818:Animals; D002401:Cathepsin B / Q000378:metabolism; D002415:Cats; D010450:Endopeptidases / Q000378:metabolism*; D005643:Fucose / Q000032:analysis; D006023:Glycoproteins / Q000032:analysis*; D006651:Histocytochemistry; D007958:Leukocyte Count; D008247:Lysosomes / Q000201:enzymology; D010034:Otitis Media with Effusion / Q000097:blood / Q000201:enzymology / Q000378:metabolism*; D010196:Pancreatic Elastase / Q000378:metabolism; D011506:Proteins / Q000032:analysis
chemical_list: D000418:Albumins; D006023:Glycoproteins; D011506:Proteins; D005643:Fucose; D010450:Endopeptidases; D010196:Pancreatic Elastase; D002401:Cathepsin B