An angiogenic growth factor produced by the blood’s platelet cells which attracts the growth of capillaries into the vicinity of a fresh wound. This action releases still other growth factors, and starts the process of building a fibrin network, to support the subsequent (blood) clot. PDGF is a competence factor (i.e., a growth factor that is required to make a cell able or competent to react to other growth factors). PDGF is normally contained within the platelet cells, so does not circulate in the blood in a form enabling it to be freely available to its “target cells.” This “containment” of PDGF in platelets ensures site-specific delivery of the PDGF directly to a wound site, so stimulus (i.e., of capillary growth) is localized to the actual wound site. After PDGF has caused the formation of the initial clot at a wound site, PDGF attracts connective tissue cells into the vicinity of the wound (to start the tissue-repair process). PDGF also acts as a mitogen (substance causing cell to divide and thus multiply) for connective tissue cells, granulocytes, and monocytes (each of which is involved in the wound’s healing process).
A polypeptide that stimulates collagen synthesis, smooth muscle formation, tissue repair, and the proliferation of fibroblasts and microglia.