小鼠皮肤光老化动物模型建立方法的改良

Improvement of establishing skin photoaging model in mice

目的改良小鼠皮肤光老化动物模型的建立方法,为临床防治皮肤光老化打下基础。方法设计制作一种构建小鼠皮肤光老化动物模型的装置,利用装置中紫外线(UVA 315~400nm;UVB 280~315nm)照射ICR小鼠,3次/周,共12周,累计照射剂量:UVA为151.20J/cm2,UVB为22.68J/cm^2;观察照射部位皮肤的临床表现、组织病理及超微结构的改变情况,测定皮肤中羟脯氨酸含量。结果与正常对照组小鼠皮肤比较,模型组皮肤出现粗糙增厚、弹性丧失、粗深皱纹、毛细血管扩张、脱屑及皮革样外观;组织病理可见表皮不规则增厚,真皮胶原纤维变性,断裂减少,排列紊乱,分布不均;超微结构显示胶原纤维排列紊乱,分布不均,周期性横纹不清,横断面胶原纤维直径增大,粗细不等;皮肤中羟脯氨酸含量显著减少(P<0.01)。提示造模成功。结论利用改良的自制造模装置建立ICR小鼠皮肤光老化动物模型是一种简便易行、经济实用、可复性强的方法。

Objective To improve the method of establishing skin photoaging model in mice so as to provide basis for the prevention and treatment of skin photoaging. Methods A device for establishing skin photoaging model in mice was designed and made. ICR mice were irradiated under ultraviolet A （UVA 315 -- 400 nm） and ultraviolet B （UVB 280--315 nm） with the device for 12 weeks （three times a week）, at the total dose of UVA and UVB of 151. 20 J/cm2 and 22.68 J/cm2 , respectively. The irradiated skin was analyzed by clinical observation, histopathologic examination, electron microscopy; the hydroxyproline content in the skin was determined. Results Compared with those in control group, clinical signs in model group included skin coarseness, increased thickness, loss of resilience, deep and coarse wrinkles, telangiectases, scales, and a leathery appearance. Histopathologic examination showed that the epidermis was hypertrophic and that collagen fibers in the dermis were denatured, disorganized, decreased, and unevenly distributed. These findings were supported by electron microscopy. The hydroxyproline content in model group decreased significantly （P〈0.01）, suggesting that the skin photoaging model in ICR mice was established successfully. Conclusion This improved method is easy, economical and reproducible. It can be widely applied to research on skin photoaging.