The effects of UVA and UVB on proliferation and melanization in SK 23 melanoma cell lines / 대한피부과학회지

ABSTRACT

BACKGROUND: The visible cutaneous pigmentary response to ultraviolet A(UVA) is immediate, whereas ultraviolet B(UVB)-induced pigmentation appears after a delay of several days. However, some investigators reported that UVA also can induce delayed taniing. OBJECTIVE: In order to determine whether the pigmentation induceil by UVA irradiation is accompanied by melanocytes responses which are the same or different from those following a UVB-indueed tan, we irraiated malignant melanoma cells to UVA or UVB. METHOD: On the 7th day after irradiation of UVA or UVB, we exa nined the cell counts and the melanin content of control and experimental groups. RESULTS: Although a dose of 10 J/cm decreased the number of manignant melanoma cells, there was no significant difference between the control and UVA-exposure griiups. But there was a significant decrease after UVB-exposun. UVB-exposure groups showed a significant increase of melanin cortent. A dose of 10 J/cm of UVA also induced a significant increase of melanin content. CONCLUSIONS: The data suggest that UVA at a clinically relevant dose has a significant effect on human melanocytes. So, UVA very likely plays a role in the increased, melanization associated with delayed tanning.