| Objective:The research on the mechanism of chronic wound has become one of the hotspots of clinical research,in which local tissue ischemia and hypoxia is the common feature of most chronic wounds.At present,the skin flap is designed and removed artificially on the body surface of animals.changing the local blood supply pattern of the wound has been proved to be a classical and effective method to prepare the animal model of ischemic and hypoxic wound.In this study,the widely used "rat dorsal double pedicle skin flap model" was improved in order to explore a rat ischemia and hypoxia wound model with more prominent characteristics of ischemia and hypoxia and more convenient preparation method.it provides another choice for the research based on animal model.Method:The model of ischemic and anoxic wound was established by traditional dorsal rectangular double-pedicled skin flap in SD male rats,and all the vertical perforating branches between the superficial fascia layer and the deep fascia layer of the flap were completely severed.According to the different characteristics of the experiment,the rats were randomly divided into 4 groups: group A,classical single wound with superficial fascia preservation group,group B,classical single wound with superficial fascia removal group,group C,modified three-wound(C-head,C-middle,C-tail)superficial fascia preservation group,and D group,modified three-wound(D-head,D-middle,D-tail)superficial fascia removal group.The wound healing of each group was observed,and the histomorphology was studied by HE and Masson staining,and the expression of ischemia and hypoxia related factors such as HIF-1 ? and CD31 in the wound was compared by immunohistochemical method.Results: 1?The wound healing time in group B was significantly longer than that in group A(P<0.01),and in the comparison between groups with the same location and whether to retain the superficial fascia of the wound base.The healing time in group C-middle was significantly longer than that in group A(P<0.01),the healing time in group D-middle was significantly longer than that in group B(P<0.01),and the healing time in group D-middle was significantly longer than that in group C-middle(P<0.01).In the comparison between group C and group D,the healing time in group C-middle was significantly longer than that in group C-head and group C-tail(P<0.01),and the healing time in group D-middle was significantly longer than that in group D-head and D-tail(P<0.01).2?When all the wounds in group A have healed,the results of HE staining showed that some skin appendages regenerated,epidermis regenerated and dermis thickened in B,C-head and D-head groups.Masson staining showed that the arrangement of collagen fibers in group B was more dispersed than that in group A at the same time point(P<0.05),the formation of collagen in group C-middle was significantly less than that in group A(P<0.01).In group D-middle,a large number of inflammatory cells infiltrated and collagen formation was significantly less than that in group B(P<0.01).In the process of wound healing,the formation of collagen in group D-middle was significantly less than that in group C-middle(P<0.01).In comparison between group C and group D,it was also found that the arrangement of collagen in the middle of the wound was significantly less than that of the head and tail wound(P<0.05).3?The results of CD31 immunohistochemistry showed that: The expression of wound healing in group A was significantly higher than that in group B during wound healing(P<0.01),the expression of group C-middle was significantly lower than that of group A during the whole healing process(P<0.01),the expression in group D-middle was significantly lower than that in group B(P<0.05).The expression in D-middle group was significantly lower than that in D-head and D-tail group(P<0.01).4?The expression in C-middle group was significantly lower than that in C-head(P<0.01),however,there is no consistency in the whole process of the C-tail group in the group.HIF-1 ? immunohistochemical results: During the whole process of wound healing,there was a higher expression of HIF-1 ? in group C-middle and group D-middle during the whole process of wound healing(P<0.01).In the comparison between groups,the level of group C-middle was significantly higher than that of group A(P<0.01).The expression in group D-middle was significantly higher than that in group B(P<0.05).Conclusion: 1?This study found that through the improved model,the wound healing was significantly delayed than before,at the same time,the preparation of three wounds in a single skin flap made the characteristics of ischemia and hypoxia of the wound in the center more prominent,which could provide a comparative advantage in the group.2?Through a simple method of removing the superficial fascia of the wound base,the interference of conventional placement of foreign bodies can be avoided,and the effect of the model can not be changed. |
PDF Full Text Request