A MECHANICAL STUDY OF TENSE COLLAGEN LATTICES

A new device is described, which allows the quantification, over 36 da ys, of the isometric force generated in collagen lattices whose contra ction has been prevented. Maximal force was achieved within 24 h and w as then kept constant. It was positively correlated with collagen conc entration at baseline. These data are in contrast with contraction of freely retracting lattices and indicate that the working mechanisms ar e different. In tense lattices, cells became spindle-shaped and orient ed along the tension axis. Multiplication was rapid up to the 3rd day, then became much slower just as if the force per cell had to be relax ed from a maximum 2.13 +/- 0.20 10(-7) N per cell to a constant level approximately 1 10(-7) N per cell. Finally the isometric force was fou nd to be inversely proportional to the distance between retainers. The se data support the view that the behaviour of tense collagen lattices is more closely related to that or mormal skin than freely retracting lattices, and that mechanical stress influences the internal structur e of the lattice.