Thrombin, binding to receptors of the protease-activated receptor (PAR) family, is involved in wound healing by inducing reparation processes and regulating the activity of mast cells, which secrete mediators of inflammation. Using thrombin receptor agonist peptide (TRAP-6) for the activation of rat mast cells, the effect of several receptors, including PAR-1, on mast cells was demonstrated. It was shown that TRAP increases the concentration of Ca+2in the cytoplasm of mast cells and regulates cell degranulation, while releasing nitrogen oxide. Thrombin encapsulated in poly(N-vinyl caprolactam)-calcium alginate (PVCL-Ca-Alg) hydrogel films promotes wound healing in rats as demonstrated by the acceleration of fibroblast proliferation and neovascularization. © 1998 MAHK Hayka/Interperiodica Publishing.