增生性瘢痕动物实验模型的建立与应用

目的建立由动物自身产生的增生性瘢痕实验模型.方法选用47只日本大耳白兔,在耳腹侧面制作6mm圆形全层皮肤缺损创面、1.5cm×4.5cm长方形创面以及耳背圆形创面共388个,进行组织学等多项观察.结果70%兔耳圆形创面可发生与人增生性瘢痕类似的增生块,增生块持续时间最长为150d;长方形创面增生块发生率为80%以上,持续时间已超过262d.增生块内有特征性的结节或漩涡状结构.创基注入TGF-β1、IFN-y,可以促进或抑制增生块的发生.原位杂交,查明内源性TGF-β1mRNA为强阳性表达.利用此模型证实成纤维细胞凋亡在病理性瘢痕发生、发展过程中起着重要的调控作用.结论兔耳可以产生与人增生性瘢痕类似的病理改变,可以用作瘢痕研究的实验模型.

Establishment and application of experimental animal model for hypertrophic scar

OBJECTIVE: To establish a real animal model for hypertrophic scar. METHODS: 388 wounds on the ears of 47 rabbits were created including rounds 6 mm in diamiter on ventrol or dorsal side and 1.5 cm x 4.5 cm rectangular wounds. Histological and histochemical analyses, in situ hybridization and cell apoptosis were tested. RESULTS: 70 percent of the wounds can from excess dermal scarring which is similar to human hypertrophic scar. The hight of excess dermal scarring is as 3-4 times high as original ventol skin. The excess scarring can last 150 days at the most. while 80 percent appears on rectangular wounds and it lasts more than 262 days. Large amount of fibroblasts, nodular and spiral structures exist in excessive dermal scarring. Local injection of TGF-beta 1 and IFN-r can promote and inhibit the formation of excessive dermal scarring respectively. SDS-PAGE shows that type III collagen content increased in excessive dermal scarring. In situ hybridization shows long-lasting expression of type I and III precollagen mRNA in excessive dermal scarrint. TGF-beta 1 mRNA also cope with that of precollagen. Fibroblast apoptosis in excessive dermal scarring of this model indicate that fibroblast apoptosis plays an important role in the process of occurrance, development of abnormal scar. CONCLUSION: After wounding, rabbit ears can produce excessive dermal scarring which is similar to human hypertrophic scar. This can be used as an experimental model for the study of cicatrix.