Fig. 2.

Contraction of collagen gels by cardiac fibroblasts. (a) The volume of fibroblast populated collagen gels, as determined by the volume of buffer displaced by the gels, decreased throughout the course of the contraction with the most significant decreases occurring in the first 12 h. (b) Gel diameter also decreased during the observation period, paralleling observed volume changes, with the greatest decrease in gel diameter in the first 12 h. The addition of ascorbic acid, a cofactor necessary for the modification and assembly of collagen, to culture media did not alter the rate of gel contraction. Both figures represent an n = 3 gels from three independent experiments and error bars represent standard deviations