Shear stress alters pleural mesothelial cell permeability in culture. Waters, Christopher M., Matthew R. Glucksberg, Natacha Depaola, Julie Chang, and James B. Grotberg. Departments of Anesthesia and Biomedical Engineering, Northwestern University, Chicago, IL 60611
APStracts 3:0129A, 1996.
The sliding motion of the lung against the chest wall creates a shear stress in the pleural space which can be as high as 60 dynes/cm2 depending upon the respiration rate. Such shear stresses may affect the mesothelial cells which line the pleural space on the lung (visceral pleura) and chest wall (parietal pleura). When exposed to shear stress (17 dynes/cm2) in a parallel plate flow chamber for 22 hours, rat visceral pleura mesothelial cells were not altered morphologically and did not align in the direction of flow, in contrast to the shape changes observed for bovine aortic endothelial cells. Using mesothelial cells cultured on porous microcarrier beads, we measured the permeability of the cells at different flows in a cell-column chromatography assay. The permeabilities to sodium fluorescein and cyanocobalamin increased from 8.2 + 1.0 and 7.8 + 0.7 x 10-5 cm/s to 22.5 + 1.2 and 21.8 + 3.0 x 10-5 cm/s, respectively, when the flow was increased from 0.9 to 3.5 ml/min (corresponding to average shear stresses of 4.7 to 18.4 dynes/cm2). The permeabilities returned to baseline values when the flow was reduced. Cytochalasin D stimulated an increase in permeability which was not augmented by a subsequent increase in shear stress. These results suggest that the barrier function of mesothelial cells is responsive to changes in fluid shear stress.

Received 26 January 1995; accepted in final form 13 February
1996.
APS Manuscript Number A97-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96