Morphological alteration of fibroblasts mechanically stressed in a collagen lattice

The behavior of fibroblast-populated collagen lattices under mechanical stress was studied. Lattice retraction was blocked to allow the application of mechanical stress by contraction of the fibroblasts against the fixed ends of the lattice. The forces were modulated by varying the collagen/fibroblast ratio and the amount of collagen fibrils produced, by which the forces were transmitted. Transmission electron microscopy showed several disturbances of fibroblast ultrastructure, with empty and full vacuoles, lamellar bodies and signs of cytolysis. It is suggested that the morphological alterations in the fibroblasts may constitute a feedback reaction to the mechanical stress.