欧前胡素对体外培养的人表皮黑素细胞Rab27a和酪氨酸酶的作用

目的： 观察欧前胡素对体外培养的人表皮黑素细胞转运相关蛋白Rab27a和酪氨酸酶的作用。方法：体外分离、纯化培养人表皮黑素细胞。随机分为空白对照组和欧前胡素处理组，以50或25 μmol/L欧前胡素作用48 h后观察黑素细胞形态，免疫荧光法检测Rab27a 和酪氨酸酶在黑素细胞中的定位及变化，应用透射电镜观察黑素细胞黑素小体的超微结构。结果：欧前胡素作用48 h后，黑素细胞的树状突起缩短，免疫荧光检测显示，黑素细胞Rab27a和酪氨酸酶蛋白在细胞内定位未见明显变化，但欧前胡素作用后Rab27a蛋白的荧光强度轻度增强(P<0.05)，而酪氨酸酶荧光强度降低(P<0.05)。透射电镜结果可见黑素细胞中的黑素小体数量减少。结论：欧前胡素对体外培养的人表皮黑素细胞Rab27a表达呈促进作用，对酪氨酸酶活性及黑素合成呈抑制作用。

Effects of imperatorin on Rab27a and tyrosinase in cultured human epider mal melanocytes

To investigate the effects of imperatorin on Rab27a and tyrosinase in cultured human epidermal melanocytes. METHODS：Human epidermal melanocytes were separated,purified and cultured in vitro. Melanocytes were randomly divided into control group and imperatorin group. After 48 h incubation with culture medium M254 or imperatorin（50 or 25 μmol/L）,the morphology of melanocytes was examined by inverted phase contrast microscopy. The effects of imperatorin on Rab27a and tyrosinase in melanocytes were investigated by immunofluoresent assay. The ultrastructures of melanocytes and melanosomes were studied by transmission electron microscopy. RESULTS：The melanocytes cultured with imperatorin for 48 h had shorter dendrites. Immunofluorescence microscopy showed that the location of Rab27a and tyrosinase in melanocytes were not obviously changed,but the fluorescence intensity of Rab27a was enhanced （P〈0.05） and tyrosinase attenuated （P〈0.05）. Fewer melanosomes found in the cultured human epidermal melanocytes by transmission electron microscopy. CONCLUSION：Imperatorin promoted the expression of Rab27a and inhibited tyrosinase activity.