Abstract
Background & Aims : Pulmonary epithelial cells line the human respiratory tract and are covered with respiratory tract mucus. Fluid flow affects them, because they are exposed to the shearing force of the mucus slab. In this study, we investigated the effect of mechanical fluid flow on the proliferation by A549 pulmonary epithelial cells. Methods : We used a Mild mixer to produce fluid flow by rotating the stand. Results : Mechanical fluid flow enhanced proliferation by A549 cells, and the stimulation of cell proliferation was unaffected by either the competitive inhibitor of nitric oxide synthase NG-monomethyl-L-arginine or by sodium nitroprusside, which spontaneously generates nitric oxide. However, it was reduced by the guanylate cyclase inhibitor methylene blue. Conclusions : These findings suggest that mechanical fluid flow activates guanylate cyclase. Mechanical fluid flow may enhance the proliferation of pulmonary epithelial cells and thereby facilitate the repair of the denuded epithelium in asthma.
