title: Alveolar accumulation of hyaluronan and alveolar cellular response in bleomycin-induced alveolitis.
abstract: Hyaluronan (HA) accumulating in the alveolar interstitial tissue of rats injured by a single intratracheal instillation of bleomycin has been visualized histologically and assayed. HA was present already by Day 1 after bleomycin treatment, increased to a maximum value on Days 3 and 7 and then declined. A time-dependent relationship between this early connective tissue response and the invasion of inflammatory cells in the alveolar tissue was apparent. The dominating invading cells by Day 1 were granulocytes showing positive staining for the monoclonal antibody OX-42 reflecting the C3b receptor. The numbers of macrophages expressing class II antigens started to increase on Day 1, reaching a maximum on Days 3-7 and then declined. Macrophages were the dominating OX-42+ cells by Day 7. The appearance of W3/13+ cells ("pan-T-lymphocytes") showed a similar pattern to that for the class II expressing macrophages. The number of cells expressing CD4 antigen increased until Day 3 and levelled off on Day 30 whilst the largest number of cells expressing CD8 antigen was seen on Day 30. Few cells expressing B-cell phenotype outside lymph nodules were identified. Alveolar lining epithelial cells, probably epithelial type II cells, expressed class II antigens by Days 3-14. The time-related accumulation of HA and the appearance of T-cells, macrophages and granulocytes expressing signs of activation suggests that these cells may be involved in the early connective tissue response of the lung injured by bleomycin.
authors.affiliation: Dept. of Lung Medicine, Uppsala University, Akademiska sjukhuset, Sweden.
authors.forename: O
authors.initials: O
authors.lastname: Nettelbladt
authors.forename: A
authors.initials: A
authors.lastname: Scheynius
authors.forename: J
authors.initials: J
authors.lastname: Bergh
authors.forename: A
authors.initials: A
authors.lastname: Tengblad
authors.forename: R
authors.initials: R
authors.lastname: Hällgren
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001761:Bleomycin / Q000009:adverse effects*; D006098:Granulocytes / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006820:Hyaluronic Acid / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D008264:Macrophages / Q000276:immunology; D008297:Male; D011650:Pulmonary Alveoli / Q000276:immunology / Q000378:metabolism*; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II; D001761:Bleomycin; D006820:Hyaluronic Acid