Effects of interferon-γ on and Smad7 in wound healing of rats' skin

Objective To observe the effect of Smad7 in wound healing of rats' skin,and to investigate the growth of granulation tissue and fibroblast count.To analyze the mechanism of IFN-γ on signal transduction of Smad7.Methods Full thickness excisional wound on the back of rats were used as wound models.The rats were divided randomly into 5groups 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 E].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 Smad7.Results The growth of granulation tissue and fibroblast count of groups C and D were less than groups A and B at the same day(P0.001).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 Smad7 among the groups A,B and groups C,D(P0.001),Group E was between them(P0.05).The expression of Smad7 on 3rd and 14th days after wound was higher than other days(P0.05).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