Angiogenesis and Growth Factors in Ulcer Healing

Angiogenesis, i.e., endothelial-cell proliferation and tube formation in postembryonic tissue, is a crucial element in granulation tissue production. The formation of granulation tissue, i.e., angiogenesis followed by proliferation of fibroblasts and deposition of collagen, on the other hand, is a rate-limiting step in the repair of major tissue injury (e.g., after the loss of cardiac or smooth muscle). Only in certain organs such as the liver, adrenal and renal cortex, the regeneration involves the proliferation of original parenchymal cells that fast replace the lost tissue.