title: A hypothesis: factor VII governs clot formation, tissue repair and apoptosis.
abstract: A hypothesis: thrombin is a "Universal Enzyme of Energy Transduction" that employs ATP energy in flowing blood to activate biochemical reactions and cell effects in both hemostasis and tissue repair. All cells possess PAR-1 (thrombin) receptors and are affected by thrombin elevations, and thrombin effects on individual cell types are determined by their unique complement of PAR-1 receptors. Disruption of the vascular endothelium (VE) activates a tissue repair mechanism (TRM) consisting of the VE, tissue factor (TF), and circulating Factors VII, IX and X that governs localized thrombin elevations to activate clot formation and cellular effects that repair tissue damage. The culmination of the repair process occurs with the restoration of the VE followed by declines in thrombin production that causes Apoptosis ("programmed cell death") in wound-healing fibroblasts, which functions as a mechanism to draw wound edges together. The location and magnitude of TRM activity governs the location and magnitude of Factor VIII activity and clot formation, but the large size of Factor VIII prevents it from penetrating the clot formed by its activity, so that its effects are self-limiting. Factors VII, IX and X function primarily as tissue repair enzymes, while Factor VIII and Factor XIII are the only serine protease enzymes in the "Coagulation Cascade" that are exclusively associated with hemostasis.
authors: Lewis_coleman@yahoo.com
authors: Lewis S
authors: LS
authors: Coleman
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D001777:Blood Coagulation / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology; D005167:Factor VII / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D013917:Thrombin / Q000502:physiology; D013925:Thromboplastin / Q000502:physiology; D014945:Wound Healing / Q000502:physiology*
chemical_list: D005167:Factor VII; D013925:Thromboplastin; D013917:Thrombin