Relationship Between The Expression Of MMP-2 And MMP-9 In Rat Skin And The Injury Time

Objective: To explore the expression of MMP-2 and MMP-9 in rat skin after injury and its relationship with the wound time, in order to supply an experimental evidence for the prediction of injury time. Methods: After a model of incision of rat's skin was set,immuno-histochemistry technique and auto-image analysis were used to study the expression of MMP-2 and MMP-9 at different post-traumatic time intervals in both antemortem and post-mortem groups.Results: The expression of MMP-2 and MMP-9 in ante mortem group was higher than that in the normal control group(P<0.05).However,in post-mortem injury group,there were no significant changes in anti-MMP-2 and MMP-9 immuno-reactivities in the area of injury and around the area of injury, compared with the normal control group (P>0.05). Further,the expression of MMP-2 could be detected as increasing at 0.5 h,and reached maximum on 3 d, maintained the high level to the 5th day, then decreased gradually , returned to norma1 lastly on 12～14 d. Compared with MMP -2, the expression of MMP-9 could be detected increasing at l h,and reached maximum on 3 d,maintained the high level to the 5th day, then decreased gradually, returned to norma1 lastly on 12～14 d. From 0.5 h to 3 d of wound interva1,the expression of MMP isoforms were identified in a large number of infiltrating neutrophilic [0] granulocytes , afterwards the fibroblastic cells(FBCs) accounted for the most part of the MMP-2 and MMP-9 positive cells.Conclusion: The expression of MMP-2 and MMP-9 in rat's skin is time dependent after skin injury, which could be used as a bio-marker to determine the time of injury.