Objective: To assess the protective effect of Tempol on skin photoaging caused by UVB irradiation in hairless mice. Methods: Seventy-two hairless mice were divided into control (group A), UVB irradiation alone, (groupB) UVB irradiation after topical application 0.36％ Tempol for one hour (group C), for two hours (group D), for four hours (group E) and for eight hours (group F). After UVB irradiation the content of collagen and elastic fibers and pathological changes in dermis of the mice were observed under microscopy. The content of malondialdehyde and hydroxyproline in dermis was measured by biochemistry method. Results: In group B, C, E and F the collagen and elastic fibers in dermis became thicker, fragmented and disarranged, and the content of malondialdehyde content was significantly increased and the content of hydroxyproline was significantly decreased compared to group A and B ( P ＜0.01).Conclusion: Topical application of 0.36％ Tempol can protect hairless mice from photoaging caused by UVB irradiation in hairless mice. The effect takes place from 1 to 4 hours after topical application.%目的:评价Tempol对UVB所致无毛鼠皮肤光老化的防护作用.方法:72只无毛鼠分为正常对照组(A组)、UVB照射对照组(B组)、外用0.36%Tempol 1 h后照射tNB组(C组)、外用0.36%Tempol 2 h后照射UVB组(D组)、外用0.36%Tempol 4 h后照射UVB组(E组)和外用0.36%Tempol 8 h后照射UVB组(F组).末次UVB照射后取其背部皮肤,在显微镜下观察真皮内胶原纤维和弹力纤维含量的变化及病理形态学改变.以生化分析方法测定丙二醛(MDA)及羟脯氨酸(HYP)含量.结果:B、C、E和F组真皮胶原纤维及弹力纤维均增粗、断裂、排列紊乱,皮肤丙二醛含量均显著升高,皮肤羟脯氨酸含量均显著下降,与A和D组比较差异有统计学意义(P<0.01).结论:外用0.36%Tempol对UVB所致无毛鼠皮肤光老化具有防护作用,有效防护时段可能在用药后1-4 h.
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