RESUMO
Objective To study the changes of skin wrinkles in hairless mice while exposed to ultraviolet. Methods The hairless mice were irradiated under long-wave ultraviolet ray (UVA), medium-frequency wave ultraviolet ray (UVB) and the combination of the two for 20 weeks. Total dose of UVA was 222J/cm~2, and that of UVB was 5.9J/ cm~2. After irradiation, the skin wrinkling of animals were analysed by the naked eye, dermatoglyphics enlarges and applied color skin system of pathologic portrait quantitative analysis. Results Control group: The hairless mice skin were fine and delicate, the ditch and ridge of skin distributed even, and had no the obvious cornification. Long wave ultraviolet ray (UVA) set: The skin was slightly rough, skin ditch and ridge distributed still even, and had no obvious cornification; quantitative analysis had no the obvious difference from that of control group. Medium-frequency wave ultraviolet ray (UVB) set: The dermatoglyphics were disorderly, and the skin ditch deepened, widened, and the skin ridge increased the breadth and obvious cornification, and quantitative analysis had obvious difference from that of control group. Long wave and medium-frequency wave ultraviolet ray (UVA+ UVB) set: The dermatoglyphics was disorderly, and the skin ditch deepened, widened, the skin ridge increased the breadth, skin cornification was more obvious, quantitative analysis had obvious difference from that of control group. Conclusions The qualitative and quantitative changes of the wrinkles in the ultraviolet irradiated skin of hairless mice are related to ultraviolet B but not to UVA. UVB is a key factor of skin wrinkling in UV-irradiation.