Abstract: Objective To explore the relationship between the expression change of cytokines and the wound age during the healing process of rats skin wound .Methods Immunohistochemical and image-analysis methods were performed on vital skin wounds(after incision 0.5-168h am) and postmortem damage(after incision 0.5-6h pm).Results The expression of the cytokines PDGF-β,PDGFR-β, TGF-β1, and bFGF in the epithelial cells was already enhanced since 0.5h am after damage and their strongest expression reaction was seen at 24-96h am. In addition, the expression of PDGF-β, PDGFR-β, TGF-β1 and bFGF was also found in the macrophages and the fibroblasts of the granulation tissue, and the expression changes in the postmortem damage group showed that the skin tissue within 0.5-3h after incision showed immunohistochemical changes but weakly expression and 3h thereafter no any change was found. Conclusion The expression characteristics of the above mentioned cytokines in wound repair should be related to the wound age and it reminds therefore that they may be used as immunohistochemical criteria for accurate determining the wound age.

Key words: wound healing, expression of cytokines, wound age estimation