We studied responses of endothelial and epithelial cells in the thin portion of the air-blood barrier to a rise in interstitial pressure caused by an increase in extravascular water (interstitial edema) obtained in anesthetized rabbits receiving saline infusion (0.5 ml . kg(-1) . min(-1) for 3 h). We obtained morphometric analyses of the cells and of their microenvironment (electron microscopy); furthermore, we also studied in lung tissue extracts the biochemical alterations of proteins responsible for signal transduction (PKC, caveolin-1) and cell-cell adhesion (CD31) and of proteins involved in membrane-to-cytoskeleton linkage (alpha-tubulin and beta-tubulin). In endothelial cells, we observed a folding of the plasma membrane with an increase in cell surface area, a doubling of plasmalemma vesicular density, and an increase in cell volume. Minor morphological changes were observed in epithelial cells. Edema did not affect the total plasmalemma amount of PKC, beta-tubulin, and caveolin-1 but alpha-tubulin and CD-31 increased. In edema, the distribution of these proteins changed between the detergent-resistant fraction of the plasma membrane (DRF, lipid microdomains) and the rest of the plasma membrane [high-density fractions (HDFs)]. PKC and tubulin isoforms shifted from the DRF to HDFs in edema, whereas caveolin-1 increased in DRF at the expense of a decrease in phosphorylated caveolin-1. The changes in cellular morphology and in plasma membrane composition suggest an early endothelial response to mechanical stimuli arising at the interstitial level subsequently to a modest (similar to5%) increase in extravascular water.
Citazione: | Daffara, R., Botto, L., Beretta, E., Conforti, E., Faini, A., Palestini, P., et al. (2004). Endothelial cells as early sensors of pulmonary interstitial edema. JOURNAL OF APPLIED PHYSIOLOGY, 97(4), 1575-1583. |
Tipo: | Articolo in rivista - Articolo scientifico |
Carattere della pubblicazione: | Scientifica |
Titolo: | Endothelial cells as early sensors of pulmonary interstitial edema |
Autori: | Daffara, R; Botto, L; Beretta, E; Conforti, E; Faini, A; Palestini, P; Miserocchi, G |
Autori: | |
Data di pubblicazione: | ott-2004 |
Lingua: | English |
Rivista: | JOURNAL OF APPLIED PHYSIOLOGY |
Digital Object Identifier (DOI): | 10.1152/japplphysiol.00236.2004 |
Appare nelle tipologie: | 01 - Articolo su rivista |