PLATELET-DERIVED GROWTH-FACTOR INDUCES FETAL WOUND FIBROSIS

The fetal response to cutaneous injury differs markedly from that of t he adult, proceeding with only minimal inflammation, minimal fibroblas t proliferation, and only essential collagen deposition. Although the sequence of events in adult wound healing is well defined and thought to be controlled in part by potent polypeptide cytokines, relatively s parse information exists regarding growth factor involvement in fetal wound repair. Thus, the authors sought to examine the effect of platel et-derived growth factor (PDGF), a putative adult wound healing regula tor, on the cellular and extracellular matrix events at a fetal wound site. SILASTIC(R) wound implants containing 0, 1.0, 5.0, or 10.0 ng of human PDGF were placed subcutaneously on the backs of 24-day-gestatio n fetal rabbits (full term, 31 days) and then harvested after either 1 , 3, or 5 days in utero. The specimens underwent standard histological processing and were evaluated in a blinded fashion. Compared with con trols, PDGF treated implants had a marked increase in acute inflammati on, fibroblast recruitment, and collagen and hyaluronic acid depositio n; these differences appeared to be largely time- and PDGF dose-depend ent. Thus, the fetal system is responsive to an adult wound healing me diator, and these data suggest that fetal repair proceeds in the absen ce of PDGF. Copyright (C) 1994 by W.B. Saunders Company