title: Some implications of augmented collagen levels with bleomycin exposure or hyperoxic exposure of lung fibroblasts: fibrosis as altered phenotypic expression.
abstract: Bleomycin is a primary fibrogenic agent which increases collagen content in a fibroblast system by a direct effect on fibroblasts. A mechanism for the increase in collagen content is an increase in the rate of collagen biosynthesis. This implies alteration of either collagen transcription or translation. Hyperoxia depresses collagen biosynthesis without changing collagen content. This implies that hyperoxia also depresses collagen degradation. The addition of phagocytes (macrophages) to hyperoxically exposed cells increases both collagen content and the rate of collagen biosynthesis. Hyperoxia is therefore a secondary fibrogenic agent. This suggests that mediators released from phagocytes alter collagen transcription or translation.
mesh_terms: D001761:Bleomycin / Q000494:pharmacology*; D002460:Cell Line; D003094:Collagen / Q000096:biosynthesis*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology*; D010641:Phenotype; D011658:Pulmonary Fibrosis / Q000235:genetics
chemical_list: D001761:Bleomycin; D003094:Collagen; D010100:Oxygen