Abstract: ] Objective To investigate the expressions of iNOS and eNOS during skin incised wound healing and theapplicability of time-dependent expressions of iNOS and eNOS to timing of wound. Methods An incised woundwas made in the dorsal skin of mouse . By using S-P method, the expression of iNOS and eNOS were studied in cu-taneous incised wound as well as normal skin in control mice. Results iNOS and eNOS expressed in epidermis,hair follicle, sebaceous gland, and the eNOS were also found in vascular endothelium in control group. Three hoursafter injuryed, the expression of iNOS and eNOS were detected in polymorphonuclear cells (PMNs) in the woundand peripheral region. From 6h to 24h of wound interval, the expression of NOS isoforms were identified in a largenumber of infiltrating PMNs and part of mononuclear cells (MNCs), afterwards the MNCs and fibroblastic cells(FBCs) accounted for the most part of the iNOS and eNOS positive cells. In addition, during wound healing, the ex-pressions of iNOS and eNOS were noticed in different level in vascular epithelial cells, especially neonatal capil-lary vessel in granulation tissue. Conclusion The results suggest that iNOS and eNOS express in polymorphonu-clear cells, macrophages and fibroblasts during healing process of skin incised wound in mice. Furthermore, iNOSand eNOS may play pivotal roles in all the events relating to wound healing, and the time-dependent expressions ofiNOS and eNOS may possibly be used as newmarkers for the wound age determination.

Key words: skin, wound healing, wound age determination, iNOS, eNOS, immunohistochemistry