A role for interstitial matrix in tissue tension of alveolar wall.
Single alveolar walls subjected to length-tension studies in saline and Bicine (0.2 M) undergo a progressive decay in tissue tension (TTD). We have examined the effect of different solutions on this TTD and looked for corresponding changes in the ultrastructure. Lung parenchyma was dissected to single alveolar walls (30 X 30 X 150 microns) in phosphate-buffered saline (0.15 M). Transferred to a length-tension bath, the tissue was immersed in Bicine, saline, fortified Hank's solution, 0.25% Alcian blue in saline, or a sodium dodecyl sulfate solution, for variable periods. Cycled through a given extension with peak force measured over time, these same tissues were fixed in buffered glutaraldehyde/tannic acid and processed for electron microscopy. Single alveolar walls immersed in saline or Bicine showed a progressive TTD. Vacuoles or spaces appeared in the interstitium which with cellular disorganization progressed with the TTD. Seen within 0.3 h, the changes were well advanced at 0.6 h. In sodium dodecyl sulfate (70 mM), however, there was no TTD and structurally there was no interstitium, with only basement membranes and fibrous proteins remaining. In fortified Hank's solution or 0.25% Alcian blue the interstitial matrix, cell morphology and tissue tension were well preserved for 1 h. This study suggest that leaching of the interstitial matrix occurs in saline or Bicine, and an intact matrix is essential for the preservation of tissue tension.
D000423:Alcian Blue / Q000494:pharmacology; D000818:Animals; D001485:Basement Membrane / Q000648:ultrastructure; D003094:Collagen / Q000378:metabolism; D003238:Connective Tissue / Q000187:drug effects / Q000648:ultrastructure; D004549:Elastin / Q000378:metabolism; D005109:Extracellular Matrix / Q000502:physiology*; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D008170:Lung Compliance; D008252:Macaca fascicularis; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride / Q000494:pharmacology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013314:Stress, Mechanical; D013997:Time Factors
C027494:N,N-bis(2-hydroxyethyl)glycine; D012967:Sodium Dodecyl Sulfate; D012965:Sodium Chloride; D003094:Collagen; D004549:Elastin; D000423:Alcian Blue; D005998:Glycine