| Objective To observe the effect of transforming growth factor-β(TGF-β)and Smad7 in wound healing of rats' skin, and to investigate the growth of granulation tissue and fibroblast count. To analyze the mechanism of IFN-γon signal transduction of TGF-β1 and Smad7.Methods Full thickness excisional wound on the back of rats were used as wound models. The rats were divided randomly into 5 groups as follows,①solvent control [saline solution (0.9% NaCl), group A],②IFN-γ500U/ml [group B],③IFN-γ1000U/ml[group C],④IFN-γ2000U/ml[group D],⑤blank control [group C].And 2 rats were compared as normal control. Wound tissues were collected on the 3rd,7th, 10th, 14th and 21st postwounding days. All specimens were dealed with by the pathology tectology (HE) and immunohistochemistry staining technique (SP) to observe the growth of granulation tissue, fibroblast count, the expression level of TGF-β1 and Smad7.Results In comparison with group A, the speed of wound healing in group C,D,E was more slowly(p＜0.01). The growth of granulation tissue and fibroblast count of groups C and D were less than groups A and B at the same day (P＜0.001). But on the 3rd and 21st day after wound, there were no differences all the groups on fibroblast count (P＞0.05). Image analysis showed that there were markable difference of TGF-β1 and Smad7 among the groups A,B and groups C,D (P＜0.001), Group E was between them (P＜0.05). The expression of Smad7 on 3rd and 14th daysafter wound was higher than other days (P＜0.05). So was expression of TGF-β1 on 7th day and 10th day after wound.Conclusion IFN-γcan make growth of granulation tissue slow down and make fibroblast count reduce in wound healing of rats' skin. After administration, the expression of Smad7 is enhancing but that of TGF-β1 is weaken. Effectively controlling the expressions of Smad7 and TGF-β1 might result in accelerating wound healing.
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