title: Immunolocalization of cysteine proteinases (cathepsins) and cysteine proteinase inhibitors (salarin and salmon kininogen) in Atlantic salmon, Salmo salar.
abstract: Tissue localization of cysteine proteinases (cathepsins) and their inhibitors (salarin, salmon kininogen) was performed in tissues of the Atlantic salmon. In skin, both epidermis and dermis were strongly stained by antisera against salarin and salmon kininogen. In epidermis the intercellular space seemed to be heavily stained (salarin). In kidney, the inhibitors were mainly localized to the interstitial capillaries. Also, some epithelial cells of the tubules (salarin) and some cells of the interstitium were stained. Mostly, the staining had a diffuse cytoplasmic localization. In the liver some hepatocytes were strongly positive for salarin and salmon kininogen. Purified fish cysteine proteinase inhibitors were not found to inhibit the growth of fish pathogenic bacteria and viruses. In the trunk kidney cathepsins B and L were localized in epithelial cells of the tubules (proximal part) and in cells of the interstitium. Mostly, the staining showed a prominent lysosomal localization. In head kidney large macrophage-like cells were positively stained for cathepsin B. The staining was localized to granula/vacuoles in the cytoplasm. In the liver, some hepatocytes were strongly stained and some were less strongly positive for cathepsin B and L. Mostly, the hepatocytes showed lysosomal staining. Cathepsin L was found in some big macrophage-like cells in the spleen. Mucosal epithelial cells of the esophagus and intestine seemed to be strongly stained for cathepsin B and L. The results show that cathepsins and their inhibitors are specifically and widely distributed in the Atlantic salmon skin indicating that they perform some biologically important and specific but so far unknown functions.
authors.affiliation: Norwegian College of Fishery Science, University of Tromsø, Tromsø, Norway.
authors.forename: Vilja
authors.initials: V
authors.lastname: Tähtinen
authors.forename: Ekkehard
authors.initials: E
authors.lastname: Weber
authors.forename: Dagmar
authors.initials: D
authors.lastname: Günther
authors.forename: Anne
authors.initials: A
authors.lastname: Ylönen
authors.forename: Nisse
authors.initials: N
authors.lastname: Kalkkinen
authors.forename: Randi
authors.initials: R
authors.lastname: Olsen
authors.forename: Mikko
authors.initials: M
authors.lastname: Järvinen
authors.forename: Karl-Ove
authors.initials: KO
authors.lastname: Söderström
authors.forename: Ari
authors.initials: A
authors.lastname: Rinne
authors.forename: Harry
authors.initials: H
authors.lastname: Björklund
authors.forename: Jarl
authors.initials: J
authors.lastname: Bøgwald
mesh_terms: D000818:Animals; D002196:Capillaries / Q000201:enzymology / Q000648:ultrastructure; D002403:Cathepsins / Q000378:metabolism* / Q000648:ultrastructure; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism* / Q000494:pharmacology; D004847:Epithelial Cells / Q000201:enzymology / Q000648:ultrastructure; D029941:Fish Proteins / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D007668:Kidney / Q000098:blood supply / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D007704:Kininogens / Q000378:metabolism*; D012474:Salmon; D014018:Tissue Distribution
chemical_list: D015853:Cysteine Proteinase Inhibitors; D029941:Fish Proteins; D006023:Glycoproteins; D007704:Kininogens; C403188:salarin protein, Salmo salar; D002403:Cathepsins