[Effects of harmaline and fluorouracil (5-FU) on human retinoblastoma cell line SO-Rb 50].

Harmaline and 5-FU were incubated with human retinoblastoma (Rb) cell line SO-Rb50 for 72 hours separately before subjected to sampling, viable cell counting and inhibition rate (IR) calculation. With concentration of 12 micrograms/ml, the IR of harmaline to SO-Rb50 cells was 96.6 +/- 1.98%, and that of 5-FU was 93.5 +/- 0.90%; the 50% inhibition concentration (IC50) was 1.437 micrograms/ml for harmaline and 0.321 micrograms/ml for 5-FU. The fact that Rb cells were sensitive to chemical therapy in vitro, but not in vivo, could be due to the blood-retinal barrier. For effective treatment of Rb, besides attempts at early diagnosis and the search for sensitive drugs, studies of the mode of drug delivery are also important.