Rabbit cranial suture fibroblasts under tension express a different collagen phenotype.

We present evidence that cells in fibrous joints respond to tensile mechanical stress by synthesizing significant quantities of type III collagen. Under normal conditions sutural fibroblasts synthesize type I collagen. Type III comprised some 20 per cent of the newly synthesized collagen in stressed joints, a level that was achieved within 24 h of the onset of tension and remained unchanged throughout a 4-day experimental period. These findings suggest that the biomechanical environment of a connective tissue cell is an important determinant of the type of collagen synthesized. However, we propose that the effect is likely to be an indirect one by virtue of its influence on the metabolic activity of the cells.