Altered Production of Fibronectin and Collagen in Hypercortisolism May Inhibit Tissue Repair

To the Editor.—

Fibronectin, a large glycoprotein found in the circulation and in the extracellular matrix of adherent cells, is present during wound healing and, like collagen, is important for tissue repair.¹Fibronectin contributes significantly to the formation of granulation tissue during wound healing.^1,2Fibroblasts migrate into the wound area and rapidly produce a transient matrix of fibronectin,²which is important for the subsequent assembly of granulation tissue components—in particular, collagens type I and type III, heparin sulfate proteoglycan, and chondroitin sulfate.¹ I and others have observed that fibronectin biosynthesis is stimulated as much as fourfold in human skin fibroblasts by physiologic concentrations of glucocorticoids.³In contrast, biosynthesis of collagens type I and III decreases as a result of glucocorticoid treatment, both in vivo and in cultured fibroblasts.⁴The temporary increase in fibronectin production during the development of granulation tissue is probably a normal