紫外线照射对裸鼠表皮角质层超微结构的影响

Ultrastructural effects of UVB irradiation on the stratum corneum in hairless mice epidermis

目的:探讨中波紫外线(ultraviolet B,UVB,270nm～320nm)照射对裸鼠表皮角质层超微结构的影响。方法:雄性裸鼠经剂量为0.15J/cm2的UVB照射,取材后经多聚甲醛、锇酸和四氧化钌固定后分别进行光镜及透射电镜观察。结果:UVB照射后,表皮细胞发生改变,表现为表皮增厚并具有一定时间滞后性,即照射后24h和48h未见明显改变,而在72h可见明显增厚。电镜观察显示紫外线照射后72h角质层脂质正常的板层状膜性结构消失,呈现出排列紊乱的中等电子致密絮凝块状结构。照射后96h变化更为明显,可查见角质层角化不全,在其细胞间隙内出现一些大小不等空泡和指纹样结构。结论:UVB照射可导致表皮角质层的形态学变化并有一定时间滞后性。

Objective： To evaluate the morphological changes of the stratum corneum in routine epidermis induced by UVB irradiation. Methods：Adult hairless mice were exposed to a single dose of UVB （0.15 J/cm^2）, the morphological changes of the stratum corneum was examined by light microscope and electron microscope using osmium tetroxide and ruthenium tetroxide postfixation. Results： There was no significant charge in 24 h and 48 h after UVB irradiation. A marked increase in the thickness of the epidermis was observed at 72 h. Electron microscopic observations revealed that the marked alterations in the intercellular domains of the stratum corneum, including the amorphous medium electron-dense material as well as the extracellular fingerprint-like structure were present within the widen space of the stratum corneum. Conclusion： The morphology of the stratum corneum appeared a series of marked changes and time hysteresis after UVB irradiation.