Abstract
The role of mesenchymes in the course of wound repair is presented, basing on experiments performed mainly in our laboratory. Two constituents in the connective tissue are considered separately, i.e. collagen and fibroblasts. The contents of this review are summarized as follows: (1) Inactivation of cellular activities by collagen fibers. Collagen fibrils greatly suppress the rate of DNA synthesis and proliferation of fibroblasts and epidermal cells. This suppresive effect is expressed by a polymerized form of collagen, but not by denatured or monomeric collagen. (2) Wound contraction might be controlled by fibroblasts. Fibroblasts can bind to collagen fibrils and contract them, resulting in a reorganization of collagen. This contractile force of fibroblasts could be a source of wound contraction. Our study strogly suggests that fibronectin is not involved in the binding of fibroblasts to collagen. (3) Physiological activities of epidermal cells largely depend on factors from mesenchymes. Epidermal cells require the presence of fibroblasts as a feeder for their proliferation at a low cell density culture. Some of this effect of feeder cells can be replaced with diffusible factors from fibroblasts.