ABSTRACT
Objective To promote the use of chemical peeling in facial rejuvenation with the phenol and croton oil peeling agents to the UVA/B-irradiated skin of hairless mice, and to provide the experimental evidence for the clinical application of the treatment of irradiated skin.Methods Sixty BALB/C hairless mice were photo-aged by use of chronic ultraviolet A and ultraviolet B irradiation for 20 weeks. After irradiation the animals were randomly divided into two groups:untreated (10 mice) and treated (50 mice). The phenol and croton oil chemical peeling agents were applied to the dorsal skin of treated animal group while it was full anesthetized. Punch biopsies were taken at 7, 14, 30, 60, and 90 days after peel for histological analysis. At 60 days after irradiation, the skin wrinkling of animals were analyzed by macroscopy, cleavage line amplification, and computer imaging analysis system. Results The treated areas of irradiated skin recovered rejuvenation and exhibited a unique connective tissue layer composed of fine collagen fibers beneath the epidermis. Conclusion The mixture of phenol-croton oil may reverses the visible stigmata of photoaging skin. Our results will be of great help to promote the use of chemical peeling in facial rejuvenation.
ABSTRACT
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.
ABSTRACT
Objective To study collagen changes in dermis of hairless mice that were exposed to ultraviolet. Methods The hairless mice was irradiated under UVA, 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 dorsal skin's collagens of animals were analysed by computer imaging analysis system, histopathologic examination, specific stains and electorn microscopy. Results The hairless mice exposed to ultraviolet A were unchanged in dermis collagen. The hairless mice was irradiated under UVB and the both UVA and UVB, and the content of collagen was decreased with less affinity for collagen staining. These findings were supported by electron microscopy, which showed fraying, thickened, and proliferating collagen, coalesced into extensive denaturalization. The ratio of types Ⅲ/Ⅰ+Ⅲ collagen was significantly increased. Conclusion The qualitative and quantitative changes of the collagen in the ultraviolet irradiated skin of hairless mice are related to ultraviolet B but not to UVA. UVB is a key factor of skin collagen damage in UV-irradiation.