背景 长期光照能诱发自由基和脂质过氧化物形成,造成视网膜损伤,探讨保护视网膜免受光损伤的方法和药物具有重要的意义. 目的 评价花青素对视网膜光损伤后大鼠视网膜组织形态和功能损伤的预防作用. 方法 将18只清洁级雄性成年SD大鼠以随机数字表法随机分为生理盐水组、花青素组及混合组,每组6只.各组大鼠于实验前记录视网膜电图(ERG)国际标准五项基本反应,然后3个组大鼠分别连续5d腹腔内注射5 ml/kg生理盐水、花青素或花青素+氢饱和生理盐水(HRS)混合液.各组大鼠均用(5000±300) lx光照度于19:00～次日7:00持续照射大鼠右眼3h,左眼遮盖,制作右眼单眼光损伤模型,完成后继续饲养5d,重复记录大鼠ERG国际标准化五项反应.检测结束后立即处死大鼠并制作视网膜切片,对各组大鼠视网膜损伤进行组织学定位,并比较不同干预组大鼠视网膜结构和功能的变化. 结果 造模前及造模后5d,3个组大鼠的体质量差异均无统计学意义(造模前:F=0.472,P=0.841;造模后:F=0.658,P=0.762).造模前3个组大鼠左眼、右眼间暗适应0.01 ERG b波、暗适应3.0 ERG a波和b波、暗适应3.0震荡电位的总幅值、明适应3.0 ERG b波及3.0闪烁光反应P1波的差异均无统计学意义(P＞0.05).造模后5d,各组大鼠损伤眼与自身对照眼相比,上述ERG五项检测各波的振幅值均出现明显下降,差异均有统计学意义(P＜0.05),尤以生理盐水组更为明显,表明光损伤模型建立成功.3个组间暗适应0.01 ERG的b波、暗适应3.0 ERG的a波和b波、暗适应3.0震荡电位的总幅值差值的差异均有统计学意义(F=4.594,P=0.029;F=3.834,P=0.037；F=12.823,P=0.000;F=3.976,P=0.032),而明适应3.0 ERG的b波差值的差异无统计学意义(F=1.488,P=0.259),其中与生理盐水组比较,花青素组与混合组双眼间暗适应0.01 ERG b波,暗适应3.0 ERG a波、b波,暗适应3.0震荡电位总幅值的差值明显降低,差异均有统计学意义(P＜0.05).3个组大鼠光照眼的视网膜外核层细胞层数均有所减少,部分位置的数据与对照眼相比,差异均有统计学意义(P＜0.05),尤其以视盘周边区域以及上部1～2 mm处最为明显；花青素组及混合组大鼠损伤视网膜外核层平均细胞层数均明显多于生理盐水组损伤眼,差异均有统计学意义(P＜0.05).结论 花青素类提取物能够预防光照引起的大鼠视网膜结构和功能损伤,花青素与HRS混合物的作用与单纯花青素类提取物作用相似.%Background Light leads to the damage of retinal function and structure by promoting the reproduction of radicals and lipid peroxides when retina is exposed to an intense light environment for a long time.It is necessary to study how to protect the retina against light-induced injury in ophthalmology.Objective The aim of this study was to evaluate the effect of anthocyanidin extracts in preventing retinal photic damage.Methods Eighteen clean male Sprague-Dawley (SD) rats were randomly assigned to normal saline group,anthocyanidin group and mixed (hydrogen-rich saline (HRS) + anthocyanidin,1:1 in volume) group and 6 rats for each.The electroretinogram (ERG) with international standardized 5 items was recorded from all the rats before experiment.Normal saline,anthocyanidin extracts or mixed solution of 5 ml/kg were intraperitoneally injected in the three groups,respectively,for consecutive 5 days.Then the diffused light with the luminance intensity of (5000±300)lx was used to irradiate the right eyes of the rats for consecutive 3 hours during 19:00 through 7:00 in a device made by our laboratory,and the left eyes were covered at the same time.The ERG was repeatedly recorded 5 days after light irradiation.The rats were sacrificed at the end of the experiment and retinal sections were prepared for the histopathological examination.The functional and structural changes of retinas were compared among the different groups.The use of the rats followed the Statement of ARVO.Results The differences of rat body weight were not statistically significant among the three groups (before experiment:F =0.472,P =0.841 ; after experiment:F =0.658,P=0.762).No any significant difference was found in scotopic 0.01 ERG b wave,scotopic 3.0 ERG a and b waves,scotopic 3.0 oscillatory potentials,photopic 3.0 ERG b wave and 3.0 flicker P1wave between the left eyes and the right eyes in the three groups before experiment (P＞0.05).The amplitudes of various waves of ERG were significantly declined in the right eyes compared with the left eyes (P＜0.05).The mean differential values of scotopic 0.01 ERG b wave,scotopic 3.0 ERG a and b waves,scotopic 3.0 oscillatory potentials were significantly different(F =4.594,P=0.029; F=3.834,P=0.037; F=12.823,P=0.000; F=3.976,P=0.032),but those in photopic 3.0 ERG b wave were not statistically significant (F =1.488,P =0.259).Compared with the normal saline group,the differential values of scotopic 0.01 ERG b wave,scotopic 3.0 ERG a and b waves,scotopic 3.0 oscillatory potentials were all reduced in the anthocyanidin group and mixed group (P ＜ 0.05).The cells of outer nuclear layer were decreased in the right eyes in the three groups compared with the left eyes,especially around the optic nerve head and the upside of the retina,with significant differences between them (P＜0.05),and those in the anthocyanidin group and mixed group were significantly less than normal saline group (P＜0.05).Conclusions Anthocyanidin has a protective effect on light-induced retinal damage of SD rats.The protective effect of anthocyanidin extracts is similar to the integrated effect of the mixed group.
展开▼
