| Popis: |
Wounds heal by a series of events controlled by an information flow from the organism as a whole to the wound and from cell to cell during the healing process. This information is mediated by many signals. Thrombin and factor XIIIa, for example, beside their coagulation effects also function as a mitogen and a cross-linking agent for many types of proteins respectively. Beside their role in primary hemostasis, blood coagulation and clot retraction, platelets contain factors in their α-granules (PDGF, PF4, β TG) which, at nM concentration, are chemotactic and mitogenic for cells invading the wound. Macrophages not only phagocytose damaged tissue and bacteria but also produce and secrete coagulation factors, activators and inhibitors of plasminogen activation, collagenase, lysosomal enzymes as well as fibronectin and a potent mitogenic factor. Growth factors produced outside the wound (e.g. somatomedins, EGF and other peptides produced in salivary glands) also stimulate wound healing. Finally the sequential appearance of different “structural” proteins during tissue repair has a regulating effect. It is suggested that it is time to make clinical use of the new basic knowledge accumulating in this field. |
