Initially, free radicals were thought to be destructive to normal tissue, and it also was thought that these free radicals should be bound to antioxidants to stop their destructive nature. Low-level free radicals were then later recognized as possibly serving as signalling messengers. Inflammation after an injury occurs as a site for significant production of ROS due to the amount of phagocytosis occurring. As wound healing progresses, things like cell proliferation and migration are present due to redox signalling of ROS. Production of hydrogen peroxide also occurs during wound healing. When hydrogen peroxide is decomposed, it generates oxygen as an end product. Redox signals are generated, and decreased tissue oxygen and tissue hypoxia will limit the signalling of redox; thus disabling the function of several growth factors such as platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and also limit some molecular mechanisms such as leukocyte recruitment.
Wounds. 2016;28(8):264-270. © 2016 HMP Communications, LLC