方法：用3000±150Lx蓝光建立hRPE细胞损伤模型； 利用流式细胞术检测照射时间分别为0、3、6、9、12、24h的6组hRPE细胞凋亡率及活性氧相对量； 利用流式细胞术检测照射0h组、照射6h组、照射6h前或后加不同浓度Vit E组(Vit E的浓度分别为10、50、100μmol/L)的hRPE细胞凋亡情况和活性氧相对量，并采用Hoechst 33258试剂染色在荧光显微镜下观察hRPE细胞的荧光强度。

结果：与照射0h组相比，照射3、6、9、12、24h组的hRPE细胞活性氧相对量明显增加(均P<0.01)，照射6、9、12、24h组的hRPE细胞凋亡率也明显增加(均P<0.01)，但照射3h组的hRPE细胞凋亡率无明显增加，差异无统计学意义(P=0.46)。与照射6h组相比，除照射6h前加入10μmol/L的hRPE细胞凋亡率(P=0.66)外，其他加Vit E的实验组hRPE细胞活性氧相对量和凋亡率明显减少、细胞中Hoechst 33258释放蓝色荧光逐渐减弱，且呈浓度依赖(均P<0.01)。与照射0h组相比，加Vit E的6组hRPE细胞活性氧相对量和凋亡率有差异(均P<0.01)。同一浓度的Vit E，除10μmol/L Vit E的hRPE细胞凋亡率在照射前或后加无差异(P=0.08)外，照射后加Vit E组比照射前加Vit E组的hRPE细胞活性氧相对量、凋亡率明显减少(均P<0.01)。

结论：hRPE细胞经蓝光照射后出现胞内活性氧相对量增多的现象早于细胞凋亡，清除胞内活性氧是减少大剂量蓝光诱导hRPE细胞损伤的思路。Vit E可保护由大剂量蓝光诱导的RPE细胞损伤，这种效应随Vit E浓度增加而增强，且照射后加入比照射前加入的效果更好。但需要一定剂量的Vit E才能显效，而且无法完全修复损伤。

METHODS: The hRPE cell injury model was established with 3000±150Lx blue light. The apoptosis rate and reactive oxygen species(ROS)of the six groups of hRPE cells were detected by flow cytometry at 0, 3, 6, 9, 12 and 24h respectively. Apoptosis and ROS in hRPE cells were detected by cytometry in 0h-irradiation group, 6h-irradiation group, and vitamin E added groups(vitamin E concentration 10, 50, 100μmol/L)before or after 6h-irradiation. The fluorescence intensity of hRPE cells was observed under a fluorescence microscope using Hoechst 33258 staining reagent.

RESULTS: Compared with the 0h-irradiation group, the relative amount of reactive oxygen species increased significantly in 3, 6, 9, 12 and 24h groups(all P<0.01), the apoptosis rate of hRPE cells increased significantly in 6, 9, 12 and 24h groups(all P<0.01), the apoptosis rate of the 3h-irradiation group was not statistically significantly increased(P=0.46). Compared with the 6h-irradiation group, the relative amounts of ROS and apoptotic rate of the six groups of hRPE cells added vitamin E were significantly decreased, and the blue fluorescence of Hoechst 33258 released in the cells gradually decreased, which was concentration dependent(all P<0.01),except for apoptosis rate of hRPE cells in the 10 μmol/L vitamin E group before irradiation(P=0.66). Compared with the 0h-irradiation group, the difference in the relative amount of ROS and apoptosis rate of hRPE cells in added groups were statistically significant(all P<0.01). At the same concentration of vitamin E, the relative amount of ROS and apoptosis rate of hRPE cells added vitamin E after irradiation were significantly lower than those added vitamin E before irradiation(all P<0.01), except for apoptosis rate of hRPE cells in the 10 μmol/L vitamin E group, which had no difference between added before and after irradiation(P=0.08).

CONCLUSION: After hRPE cells had been irradiated by blue light, the increase in the relative amount of intracellular ROS was earlier than that of apoptosis. Elimination of intracellular ROS is the idea of intercepting high doses of blue light induced hRPE cell injury. Vitamin E protects RPE cell against damage induced by high doses of blue light, and the effect becomes stronger as the concentration of vitamin E increases, which is better when added after irradiating. However, it doesn't take effect until the concentration reaches a certain level. And the damage can't be completely repaired.