The Effect of Ultraviolet B Irradiation on the Skin Barrier Function in Hairless Mice / 대한피부과학회지

ABSTRACT

BACKGROUND: Stratum corneum lipids serve as a water retainer as well as permeability barrier by forming a multi-lamellae structure in the stratum corneum. The major constituent of these lipids, ceramides, have been shown to be predominantly associated with both functions. OBJECTIVE: Exposure of human epidermis to ultraviolet(UV) irradiation leads to changes in the physiologic and biochemical features of the skin. In order to investigate the effect of UVB irradiation on the skin barrier function in hairless mice, transepidermal water loss (TEWL) and lipid composition of stratum corneum were evaluated in hairless mice. METHODS: Hairless mice were irradiated 3 times weekly for 3 weeks with suberythemal dose (0.6MED, Group I) and minimal erythemal dose(MED), Group II) of UB. The mice of Group III received high dose of UVB(3MED) on the back in a single exposure. The control was Group IV. TEWL measured by evaporimeter and lipid composition of stratum corneum appraised by high performance thin layer chromatography(HPTLC) were evaluated weekly for 3 weeks. RESULTS: 1. Each time it was measured, the values of TEWL in group I were lower than group IV, but the difference was not significant. The peak value of TEWL in group II was 8.2+/-1.56 g/cm/h on the 7th day. The increase in TEWL was markedly significant at this point(P<0.001). Although the values of TEWL on the 14th and 21th day in group E increased compared with those of the control group, the significance of the values decreased (P<0.05). 2. The peak value of TEWL in group III was 9.88+/-1.13 g/cm/h on the 2nd day, showed a markedly significant increase compared with that of the control group(P<0.001). The values of TEWL decreased to the level of the control group on the 14th day. 3. The lipid(cholesterol sulfate, ceramide and neutral lipid) and total lipid mass in group 1 were insignificantly larger than that of the group IV measured each time. On the 7th and 14th day, the amount of each three lipid and total lipid mass significantly increased (P<0.05). On the 21th day, the amount of ceramide and neutral lipid showed a significant increase(P<0.05), furthermore the total lipid mass increased pronouncedly(P<0.01) in group II. 4. The amount of the 3 kinds of lipid and total lipid mass in group III significantly increased compared with those of the control group on the 2nd day(P<0.05). After the 7th day, no significant difference of the lipid mass except neutral lipid compared with that of the control group was seen. Comparing the 2nd and 14th day, there was a significant decrease in the amount of ceramide and total lipid mass(P<0.05) CONCLUSION: These results results suggest that considerable amount of UVB irradiation given in single or repeated exposure causes the disruption of skin barrier function, but a compensatory increase of skin lipid, especially ceramide, protests it from further damage and also improves skin barrier function.