Fibroblastic cell cycling in collagen gels.

Quiescent C3H10T1/2 mouse fibroblasts resume DNA synthesis and proliferation following incubation in medium containing fresh serum both when grown in monolayer and when grown in a collagen matrix. We observed that the rate of DNA synthesis is reduced at high initial cell densities and low initial collagen concentrations. In a collagen matrix, fibroblasts contract the matrix causing an increase in cell density and collagen concentration. We studied the chronological relationship between the kinetics of DNA synthesis and the collagen matrix contraction. The rate of collagen collection per cell changes in time, dependent on initial cell and collagen concentration. The kinetics of the collagen collection showed a positive correlation with the kinetics of DNA synthesis, 16 h later.