SKH-1无毛小鼠光老化模型的建立及点阵CO_(2)激光治疗效应观察

Establishment of SKH-1 Hairless Mice Photoaging Model and Its Application in Observing the Effect of Fractional CO_(2) Laser

目的:确定SKH-1无毛小鼠光老化模型的造模方法,并将该模型用于点阵CO_(2)激光治疗效应观察。方法:将15只SKH-1无毛小鼠分为空白组、较低剂量紫外线组和较高剂量紫外线组,紫外线照射小鼠背部皮肤,通过观察小鼠背部皮肤外观、HE染色评估小鼠皮肤光老化程度,选定合适的紫外线照射剂量。10只光老化小鼠随机分为对照组与点阵CO_(2)激光治疗组,治疗前、治疗后即刻、7d、14d及28d检测经皮水分丢失(Trans-epidermal water loss,TEWL),治疗前、治疗后即刻、28d、56d行环钻活检取得皮肤组织,进行HE染色、Masson染色、阿新蓝染色及Ⅰ型、Ⅲ型胶原免疫组化染色。结果:紫外线照射后SKH-1小鼠背部皮肤出现皮肤粗糙,横向皱纹增加,胶原纤维含量显著减少、疏松、断裂,真皮变薄、表皮增厚等光老化表现,紫外线剂量过高可出现日光性角化甚至癌变。点阵CO_(2)激光治疗即刻皮肤组织内可形成锥形的微小热损伤区,TEWL即刻显著升高7倍,1~2周恢复,逐渐出现胶原新生。结论:SKH-1无毛小鼠是较理想的光老化动物实验模型,且可用于点阵激光等美容治疗后的生理与组织学研究。

Objective To determine the method of establishing SKH-1 hairless mouse photoaging model,and to use this model to observe the effect of fractional carbon dioxide laser treatment.Methods Fifteen SKH-1 hairless mice were divided into a blank group,a low-dose-UV group and a high-dose-UV group.The dorsal skin of mice was assessed by observing the appearance and HE staining,and the appropriate UV irradiation dose was selected.Then,10 photoaged mice were randomized into a control group and a fractional CO_(2) laser treatment group.Trans-epidermal water loss(TEWL)was measured before,immediately,7 d,14 d and,28 d after treatment.Punch biopsy was done before and immediately,28 days,56 days after treatment,for HE staining,Masson staining,Alcian blue staining and immunohistochemical staining for type I and type III collagen.Results After UV irradiation,the dorsal skin of UV-irradiated SKH-1 mice showed roughness,increased transverse wrinkles,significantly reduced collagen fibers,loose and fractured collagen fibers,thinner dermis and thickened epidermis.Excessive UV dose could cause solar keratosis or even carcinoma.Fractional CO_(2) laser treatment formed conical microthermal zones,with an immediate 7-fold increase in TEWL and recovery in 1-2 weeks.New collagen emerged gradually.Conclusion SKH-1 hairless mouse is an ideal experimental animal model of photoaging,and can be used for physiological and histological studies of cosmetic laser treatment.