RESUMO
Objective To explore the establishment of skin photoaging model and the protective effects of nitroxide tempol on skin in guinea pig. Methods The guinea pig skin photoageing model was established by using solar-simulaten radiation (SSR). Dermal structure was observed with hematoxylin-eosin staining. The structure and expression of elastic fiber were analyzed by Weigert's staining. The uhrastructure of dermal fibroblasts and elastic fiber were observed by electron microscopy. Tempol was used before each exposure at the concentration of 5 mg/ml or 0. 5 mg/ml, and the protective effects of tempol on skin were assessed. Results After seventeen weeks' exposure, there was typical "solar elastosis" damage in the upper dermis. Mature elastic fibers were severely degraded and there was large amount of elastotic material accumulated in the upper dermis. Dermal fibroblasts appeared metabolically hyperactive and mitochondria in the cells were damaged. Some cells even broke up. Tempol at the concentration of 5 mg/ml or 0. 5 mg/ml could prevent photodamage of the photoageing model in the dermis, and Tempol at the concentration of 5 mg/ml had stronger protective effects. Conclusions Guinea pig can be applied as an useful animal model of skin photoageing. Antioxidant tempol has photoprotective effects on photodamage of the photoageing model in guinea pig and can be used as an anti-photoageing agent.