中文摘要：

目的探讨氯离子通道阻滞剂5-硝基-2-（3苯丙氨基）苯甲酸（NPPB）在人视网膜色素上皮（RPE）细胞增生中的作用。方法培养人RPE细胞株，ARPE-19细胞；采用四甲基偶氮唑盐（MTT）比色法检测不同浓度的NPPB对ARPE-19细胞增生的影响；利用血清饥饿法对ARPE-19细胞进行细胞周期同步化，并通过流式细胞仪加以确定；进行核仁染色，观察NPPB对ARPE-19细胞周期进行中核仁变化的影响。结果NPPB浓度依赖性地抑制了ARPE—19细胞的增生；核仁染色显示了ARPE-19细胞核仁数量和形态随着细胞周期进行而发生变化，NPPB使ARPE-19细胞核仁萎缩，抑制核仁形成，使细胞处于静息状态。结论氯离子通道阻滞剂NPPB能够抑制静止期的ARPE—19细胞进入细胞周期。从而抑制ARPE—19细胞的增生。

英文摘要：

Objective To evaluate the effect of 5-nitro -2-（3-phenylpropylamino） benzoic acid（NPPB） ,a chloride channel blocker,on proliferation of cultured human retinal pigment epithelium （RPE） cells. Methods Human retinal pigment epithelium cell line,ARPE-19 cells, were cultivated in 1：1 DMEM and Ham＇ F12 culture medium containing 10% fetal calf serum under the condition of 37℃ and 5% CO2. Zero μmol/L（ control group） , 10,50,75,100 and 200 μmol/L of NPPB were added to the 10th passage of ARPE-19 cells in different culture wells respectively. Proliferation rate of cultured cells with varying concentrations of NPPB was determined by MTT assay. The cell cycle was synchronized by serum starvation and was measured by flow cytometry （FCM）. The effect of NPPB on nucleolus in various cell cycles was analyzed using Pl-staining technique. Results NPPB inhibited proliferation of ARPE-19 cells in a dose-dependent manner. At concentrations of NPPB of 50,75,100, 200 μmol/L, the inhibition rate was 9.51% ,30. 75% ,49.52% ,65.04% respectively （P 〈 0. 05）. The numbers and size of nucleolus were altered in various cell cycle depending on the concentration of NPPB. Nucleolus was atrophy, and staining of nucleolus was weaker at 24 hours after addition of serum in NPPB group,indicating a inhibitory effect of NPPB on proliferation of cells. Flow cytometry showed that ARPE-19 cells were distributed predominantly in G0/G1 phase （74. 2% of the population） at 8 hours,and 62. 2% of ARPE-19 cells entered S phase up to 15 hours,48.6% in G2/M phase up to 20 hours, and 52.8% in G1 phase again at 24 hours after serum addition. Conclusion NPPB reduces the proliferation activity of ARPE-19 cells through inhibiting transition of quiescent ARPE-19 cells into the cell cycle.