不同波长人工发光二极管光照对大鼠视网膜的影响

Effects of different wavelengths of artificial light-emitting diode on rat’s retina

目的探讨红、绿、蓝、白四种不同波长人工发光二极管(LED)光照对大鼠视网膜的影响。方法45只3周龄SD大鼠作为实验动物,分为空白对照组,以及1000 lux和2000 lux照度下的红光照射组、绿光照射组、蓝光照射组、白光照射组,每组各5只。空白对照组大鼠自然光线下饲养1个月,不同光照组采用相应波长LED进行光照,每天照射10 min,连续1个月。取各组大鼠左眼视网膜行TUNEL染色观察细胞凋亡情况,取各组大鼠右眼视网膜行Western blot检测视网膜中PARP和GFAP的蛋白相对表达量。结果照度1000 lux时,红光照射组、绿光照射组、蓝光照射组、白光照射组大鼠视网膜TUNEL染色均未见明显的细胞核阳性染色;Western blot检测结果显示,各组大鼠视网膜中cleved-PARP及GFAP蛋白相对表达量与空白对照组相比,差异均无统计学意义(均为P>0.05)。照度为2000 lux时,除空白对照组和红光照射组外,绿光照射组、蓝光照射组、白光照射组大鼠视网膜TUNEL染色后视网膜感光细胞层均可见细胞核点状阳性着染,提示存在DNA的降解断端;Western blot检测结果显示,蓝光照射组大鼠视网膜中cleved-PARP蛋白表达量(1.414±0.192)较空白对照组(0.624±0.148)增加,差异有统计学意义(P<0.05),红光照射组(0.660±0.067)、绿光照射组(0.764±0.127)、白光照射组(0.748±0.160)大鼠视网膜cleved-PARP蛋白表达与空白对照组相比,差异均无统计学意义(均为P>0.05);各组大鼠视网膜中GFAP蛋白相对表达量比较,差异均无统计学意义(均为P>0.05)。结论照度2000 lux、每天10 min光照1个月,蓝光照射的大鼠会出现视网膜光损伤表现。

Objective To investigate the effects of artificial light-emitting diodes(LED)with four different wavelengths of red,green,blue and white on the damage of rat’s retina after illumination.Methods Totally 453-week-old SD rats were used as experimental animals.They were divided into a blank control group,and red light irradiation group,green light irradiation group,blue light irradiation group and white light irradiation group each at 1000 lux and 2000 lux illuminance,with 5 rats in each group.The rats in the blank control group were reared under natural light for 1 month,and the different light groups were irradiated with LEDs of corresponding wavelengths for 10 minutes a day for 1 month.The retina of left eyes in each group of rats was taken for TUNEL apoptosis staining to observe the degree of apoptosis,and the retina of right eyes in each group of rats was taken to perform Western blot to detect the relative expression of PARP and GFAP in the retina.Results Under the illuminance of 1000 lux,the red light irradiation group,green light irradiation group,blue light irradiation group,and white light irradiation group have no obvious positive staining of nucleus in the TUNEL staining of rat’s retina.Western blot results showed that the relative expression of cleved-PARP and GFAP protein in the retina of each group was not statistically significant compared with the blank control group(all P>0.05).Under the illuminance of 2000 lux,except the blank control group and the red light irradiation group,the TUNEL staining of rat’s retina in the green light irradiation group,the blue light irradiation group,and the white light irradiation group showed positive staining of nuclei in the photoreceptor cell layer of the retina,indicating the presence of the degradation of DNA ends.Western blot detection results showed that compared with the blank control group(0.624±0.148),the expression of cleved-PARP protein in the retina of the blue light irradiation group(1.414±0.192)increased,and the difference was statistically significant(P<0.05),but the differences in protein expression of cleved-PARP rat retina in the red light irradiated group(0.660±0.067),green light group(0.764±0.127),and white light group(0.748±0.160)were not statistically significant compared with the blank control group(all P>0.05).There was no statistically significant difference in the expression of GFAP protein in the retina of rats in each group(P>0.05).Conclusion Under the condition of 2000 lux and 10 minutes per day for 1 month,the expression of apoptosis protein in the retina of blue light irradiated rats increased,which indicates that there is the presence of retinal light damage performance.