EXTRACELLULAR-MATRIX BIOLOGY IN THE LUNG

The lung and other organs are comprised of both cellular and extracell ular compartments. Interaction of these components modulates physiolog ical function at the organ, cellular, and subcellular levels. Extracel lular components in the gas-exchange region of the lung include both n oncellular interstitium and basement membranes. Connective tissue elem ents of the interstitium in part determine ventilatory function by con tributions to tissue compliance and to resistance of the diffusion bar rier. The basement membrane underlies cells of both the alveolar epith elium and the capillary endothelium; basement membrane components exer t biological effects on adjacent cells through receptor-mediated inter actions. This review emphasizes current knowledge concerning the compo sition and biological activity of extracellular matrix in the alveolar region of the lung. Matrix synthesis and turnover are also considered . Directions for future research are suggested in the context of curre nt knowledge of the lung and other model systems.