The Myofibroblast in Pulmonary Fibrosis

The pulmonary interstitium of several mammalian species contains nonmuscle cells with abundant cytoplasmic filaments composed of actin. 1 Kapanci Y Assimacopoulos A Irle C Zwahlen A Gabbiani G “Contractile interstitial cells” in pulmonary alveolar septa: a possible regulator of ventilation/perfusion ratio?. J Cell Biol. 1974; 60: 375-392 Crossref PubMed Scopus (249) Google Scholar , 2 Evans JN Adler KB The lung strip: evaluation of a method to study contractility of pulmonary parenchyma. Exp Lung Res. 1981; 2: 187-205 Crossref PubMed Scopus (34) Google Scholar , 3 Kapanci Y Mo Costabella P Cerutti P Assimacopoulos A Distribution and function of cytoskeletal proteins in lung cells with particular reference to “contractile interstitial cells.”. in: Josmin G Cantin M Methods and achievement in experimental pathology. vol 9. Karger, Basel1979: 147-168 Google Scholar Evidence indicates that these cells are capable of the contractile activity, and it has been suggested that they play a role in the matching of ventilation and perfusion. 1 Kapanci Y Assimacopoulos A Irle C Zwahlen A Gabbiani G “Contractile interstitial cells” in pulmonary alveolar septa: a possible regulator of ventilation/perfusion ratio?. J Cell Biol. 1974; 60: 375-392 Crossref PubMed Scopus (249) Google Scholar An augmentation of the contractile cell population has been described in rats with pulmonary fibrosis induced with bleomycin sulphate. 4 Evans JN Kelley J Low RB Adler KB Increased contractility of isolated lung parenchyma in an animal model of pulmonary fibrosis induced by bleomycin. Rev Respir Dis. 1982; 125: 89-94 PubMed Google Scholar In the fibrotic rat model there is an increased proportion of actin in the polymerized form (F-actin). 5 Low RB Evans JN Adler KB Effects of bleomycin induced fibrosis on lung actin content and polymerization. Am Rev Respir Dis. 1982; 125 (abst): 218 Google Scholar Furthermore it has been shown that force generation in vitro by parenchymal strips isolated from fibrotic rat lung is significantly increased compared to control. 4 Evans JN Kelley J Low RB Adler KB Increased contractility of isolated lung parenchyma in an animal model of pulmonary fibrosis induced by bleomycin. Rev Respir Dis. 1982; 125: 89-94 PubMed Google Scholar