【摘要】 [目的]探讨长波紫外线(UVA)和中波紫外线(UVB)照射人体黑素细胞作用的差异。[方法]以不同剂量UVA和UVB分别照射黑素细胞,用四甲基偶氮唑盐微量酶反应比色法(MTT)测量细胞增殖率,比色法测定酪氨酸酶活性,吸光度测定黑素含量的变化。[结果]人体黑素细胞经0~2.25J/cm2 UVA照射后,黑素含量和酪氨酸酶活性无明显改变,其中较高剂量UVA(>1.8J/cm2)可使黑素细胞存活率下降。0~0.06J/cm2 UVB能明显抑制黑素细胞存活率,并能激活酪氨酸酶和促进黑素细胞的黑素合成。[结论]离体水平UVB对黑素细胞的促黑素合成作用明显强于UVA。更多还原

【Abstract】 [Objective]To investigate the distinct response between human melanocytes separately exposed to UVA and UVB.[Methods]The proliferation rate of melanocytes was determined by MTT assay.The viability of intracellular tyrosinase was determined by photocolorimetry.The levels of intracellular melanin was evaluated by spectrophotometry.[Results]Human normal melanocytes irradiated with 0-2.25J/cm2 UVA showed no marked changes while high dose UVA(>1.8J/cm2)caused an obvious drop in cell proliferation.0-0.06 J/cm2 UVB showed significant increase in melanin content and tyrosinase activity and a drop of cell proliferation in dose-effect manner.[Conclusion]In vitro,the melanotropin synthesis of melanocytes induced by UVB was obviously greater than that by UVA.更多还原