皮肤光老化豚鼠模型构建及评价标准的探讨

Study on the Photoaged Skin Model in guinea pig

目的构建窄谱中波紫外线(NB-UVB,311-312 nm)诱导豚鼠皮肤光老化动物模型,为临床防治皮肤光老化奠定基础。方法使用NB-UVB每天亚红斑量照射豚鼠4周,用伍德灯、皮肤组织学、特殊染色及电镜等方法,进行造模前后皮肤的临床表现、组织病理、超微结构及电镜超微结构的对比观察。结果照射后皮肤出现松弛、粗糙、皮革样外观,色素斑增多;组织学表皮厚度、成纤维细胞计数进行测量分析造模前后比较差异有统计学意义(P<0.05),真皮见少量类似网状纤维,胶原纤维变性,含量减少,弹力纤维明显增多,附属器增生,炎性细胞浸润;电镜超微结构表皮各层细胞轮廓不清伴有溶解变性,角质细胞间桥粒解体,真皮中成纤维细胞内胞质空泡变性、内质网扩张、线粒体肿胀、核间隙增宽,周围胶原纤维溶解变性,胶原间隙增大,可见凋亡细胞。结论真皮及真皮基质的改变是NB-UVB引起皮肤光老化的病理基础。NB-UVB照射后豚鼠的皮肤所发生的变化与临床皮肤光老化疾病一致,因此该模型是较为理想的研究皮肤光老化的动物模型。

Objective To make a photoaging model induced by narrow - band ultraviolet irradiation （NB - UVB 311 - 312rim） in order to provide a tool for further studing on the underlying mechanism and prevention of skin photoaging. Method The guinea pigs were irradiated by NB - UVB in suberytheatosa dosage everyday which was lasted for four week. The photoaging characteris- tics of skin were detected by the Wood lamp, skin histology, special staining method and electron microscopy. Results Compared with the control group, the clinical signs of skin in slack, rough, leathery appearance and pigmentation increasing were observed in model group. The epidermal thickness and the fiber cell count were increased signficantly in model group （ P 〈 0.05 ）. The adnexal hyperplasia, degenerated collagen fibers,increased elastic fibers,inflammatory cell infiltration were observed with mocroscopy. Under the electron mi- croscope, the disintegrated desmosomes degenerated dermal fibroblasts, endoplasmic reticulum expansion, mitochondrial swelling, nuclear gap widened, increased collagen fiber gap could be observed. All above showed that the skin phooaing model in guinea pigs was made successfully. Conclusion The change of dermal and dermal matrix is the pathological basis of skin photoaging induced by NB - UVB. The changes of the guinea pigs＇ skin after being irradiated by NB - UVB are consistent with the clinical skin photoaging diseases, so it is an ideal animal model for studying the skin photoaging.