| Scar is the nature outcome of wound healing in mankind.But in some cases,such as the opening wounded may lead to abnormal scar formation and scar contracture.Thus,scar can affect the function of body and the living quality of the wounded may be greatly declined. It is plastic and reconstructive surgerons' task to explore efficiency methods of preventing and treatment abnormal scars.Lots of scholars in our plastic surgery field gave their attention to Hyaluronic acid(HA)' s biology function and most of them researched the HA effect of wound healing. In order to explore the relationship of the persisting elevation of HA level after wound healing and abnormal scar formation, we designed this experiment:Firstly,Six round wounds were performed on gaster-side of auricle with 10 mm of distance and 8.5 mm of diameter by a stiletto which were deeply to the surface of cartilage of 3 rabbits , we got the hypertrophic scar model of rabbit ears Then we observedthe growth process of saline and blank group and their histology characteristics, measured the raising height at the wound sites, calculated the occurrence of excessive tissue and analyzed the results statistically; Secondly, hypertrophic scar model of 18 rabbits were performed upon the method of the above, we selected 12 rabbits of them randomly into 3 groups. HA and hyaluronidase (HAse) and saline were injected into the local regions after the heal of partial wounds. Within 40 days after wound healing, we observed them comparatively at 6 time points, The samples stained with HE and Masson were examined histologically. With immunalhistochemical methods, we studied the contents of myofibroblast in excessive dermal scarring of each group; By using the methods of tissue digestion technique, we observed the variation of the content of hydroxyproline during scar formation.All the results suggested:1,Wounds on gaster-side of rabbit auricle can produce excessive dermal scar after healing ,and the scar can contract.2,Excessive tissue is mainly in dermal layer and the occurrence rate is about 80 percent. There are a lot of fibroblasts in excessive dermal scar in the early period, while collagen mainly exists in the late period, and some whorl-like or nodular structure can be found; The type of exudation myofibroblast existed in every group3,After nature healing, the content of HPr was increased gradually in restoration area with the 14th day being the hightest .From then on , it entered reconstruction stage . The application of HA made the proliferative stage persisting to 21th day . HAse, the negative control restrain abnormal scar formation. HPr content in HAse group presented downtrend all the while ( P<0.05 ). In contrast to HAse group , HPr contents were much higher at every stage in HA group (PO.01) .4,MFc can be found in every group ,but it is less in HA group than that in HAse group; scar constraction in HA group is more than that in the other two groups.Conclusion:1,Excessive dermal scarring may occur after the healing or through skin defect on ventral side of rabbit ,and Excessive derma: scarring of rabbit ear is similar to human hypertrophic scar .thus hypertrophic scar model is farther proved.2,Injection HA into the local regions after the heal of rabbit ears wounds forms excessive dermal scarring.3,Injection HAse into the local regions after the heal of rabbit ears wounds restrains excessive dermal scarring.4,HA restrain MFc formation by controlling a -SMA and then block the scar constraction and scar absorption. |
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