激光脱毛动物模型的建立

Effect of alexandrite laser treatment for hair removal in Tibet mini-pigs

目的采用黑毛西藏小型香猪为动物模型,探讨翠绿宝石激光脱毛术后的毛囊组织学和超微结构的改变。方法对12只黑毛白皮西藏小型香猪用翠绿宝石激光脱毛,术前、术后即刻、1h及1、3、5、10、15、30、60d分别取材,在光镜和透射电镜下观察皮肤标本。结果激光治疗术后毛囊中毛干凝固坏死、碳化及脱落,部分外根鞘及毛球细胞变性坏死;术后1h毛囊外根鞘、毛球细胞出现核固缩、核碎裂或核溶解等凋亡表现,胞浆空泡化明显,以术后1、3d达到高峰,并伴有毛乳头血管内皮变性、真皮组织充血水肿和淋巴细胞浸润。术后5d毛囊的损伤性炎症减轻,术后10、15d表皮、真皮及毛囊结构基本恢复正常,术后60d毛囊数目减少,残余毛囊结构正常。结论翠绿宝石激光对毛囊有选择性损伤作用,通过直接热凝固作用和诱导细胞凋亡造成毛囊不可逆的损伤,达到永久性脱毛的目的。黑毛西藏小型香猪可作为临床激光脱毛的动物模型。

Objective To observe the histological and ultrastructural changes of the skin and hair follicles following hair removal by alexandrite laser in Tibet mini-pigs. Methods Twelve healthy Tibet mini-pigs with dark hair were treated with alexandrite laser for hair removal. The skin specimens were taken immediately and at 1 h and 1, 3, 5, 10, 15, 30, 60 days after the laser treatment for observation under optical and transmission electron microscope. Results Laser hair removal resulted in extensive coagulation necrosis, carbonization and falling of the subcutaneous hair shafts, and some of the cells in the outer root sheath and hair bulb underwent degenerative and necrotic changes. One hour after laser treatment, the cells in the outer root sheath and bulb exhibited nuclear condensation, fragmentation and or karyolysis characteristic of cell apoptosis. The cell apoptosis reached the peak level on day 3 after the laser exposure, accompanied by endothelial degeneration in the hair papilla vessels, edema and lymphocyte infiltration in the dermal tissues. Tissue reaction and inflammation were relieved on day 5, and the dermal tissue and follicles recovered their normal structures on day 10. At 60 days after the treatment, the hair follicles decreased markedly but the structure of the residue follicles remained normal. Conclusion Alexandrite laser exposure results in selective destruction of the follicles by inducing direct coagulation and cell apoptosis to achieve permanent hair removal. Tibet mini-pigs with black hair can be used as the animal model of clinical laser hair removal.