摘要目的 探讨维A酸治疗皮肤色斑的作用机制.方法 应用不同浓度的维A酸作用于B16F10黑素瘤细胞及正常人黑素细胞,观察肘酪氨酸酶mRNA的表达、酪氨酸酶活性、黑素含量及黑素细胞增殖率的影响.结果 维A酸的作用浓度为100μmol/L时,黑素细胞酪氨酸酶mRNA表达下调均值为30.13%;当浓度为500μmol/L以上时,可使酪氨酸酶活性降低82.79%,并随着浓度的增加作用越明显;而对黑素含量的降低则需要更高的浓度(1 000μmol/L);同时,还有促进黑素细胞增殖的作用.对照组氧醌对酪氰酸酶mRNA的表达无明显影响,对色素细胞有抑制和毒性作用.结论 维A酸能够抑制黑素产生,是通过下调酪氨酸酶的表达和活性来完成.

abstractsObjective To investigate the effects and mechanism of retinoie acid on B16 marina mel-anoma cells and human melanocytes in vitro. Methods B16F10 murine melanoma cells and human mela-noeytes were cultured in culture medium which contains different concentration of components, including retinoic acid. Using reverse transcription-polymerase chain reaction (RT-PCR) mRNA expression of the tyrosinase was detected. Tyrosinase activity, melanin content and cell proliferation rate were also deter-mined. Results Retinoieacid exhibited an inhibitory effect on the expression of tyrosinase mRNA. As the concentration of retinoic acid was 100 μmol/L, treating for 72 h, the expression of tyrosinase mRNA de-creased 30.13 %, retinoic acid exhibited an inhibitory effect on tyrosinase activity and melanin production at high concentration (>500 μmol/L), and it could promote the cell proliferation. Retinoic acid and hy-droqninone could be cooperative at high concentration (1 000 μmol/L), and enhanced the down regulation of tyrosinase activity and melanin content. Retinoic acid could also mitigate the inhibitory effect of hydro-quinone on cell proliferation, so as to protect the cells from injury. Hydroquinone had no effect on tyrosi-nase gene expression at mRNA level. Conclusion Retinoic acid inhibits the synthesis of melanin by the genetic regulation at mRNA level.