| | | 牛磺酸对大鼠视网膜光化学损伤c
| | 药学本科毕业论文【关键词】 ,牛磺酸；视网膜光化学损伤；凋亡细胞；c
摘要： 目的药学本科毕业论文 观察饲料中添加牛磺酸对光化学损伤后大鼠光感受器细胞凋亡的药学本科毕业论文影响，并进一步从氧化应激基因cfos表达变化角度探讨其防护机制。方法 70只SD大鼠随机分为对照组、牛磺酸组。分别喂饲标准饲料或添加4％牛磺酸饲料喂饲15d后接受(3000±200)lx持续0，1，3，6，9，12,24h光照，凋亡细胞原位末端标记法(TUNEL)检测光感受器细胞凋亡情况并计算凋亡指数(AI)；RTPCR法及免疫印迹法检测视网膜内cfos mRNA以及蛋白表达水平。结果 感光细胞凋亡指数随光照时间延长逐渐增加，牛磺酸组AI显著低于对照组(P<005)，其中光照12h牛磺酸组与对照组AI分别为(123±47)％和(324±62)％；视网膜cfos mRNA光照1h后一过性表达增高，牛磺酸组较对照组低(P<005)；光照后视网膜cfos蛋白表达逐渐升高，于3h达峰值，牛磺酸组显著低于对照组(P<005)。结论 在视网膜光化学损伤条件下，牛磺酸可能通过抑制视网膜cfos的转录及表达，阻断光感受器细胞凋亡转导从而保护视网膜。
关键词： 牛磺酸；视网膜光化学损伤；凋亡细胞；cfos
Effects of taurine on cfos expression of rat retina after photochemical damage
Abstract： Objective To observe the effect of dietary supplementation with taurine on photoreceptor apoptosis and further investigate changes of cfos expression of rat retina after photochemical damage.Methods Seventy rats were randomly divided into control group (Control) and 4% taurine supplementation group (Taurine).The subjects were exposed to (3000±200) lx transmitted by six cold white lights for 0,1,3,6,9,12,24 h.The apoptotic photoreceptor cells were detected using TUNEL method;Total RNA and protein of retina were extracted;relative cfos mRNA levels were determined using RT-PCR and cfos protein levels were detected by western-blot analysis.Results With the light exposure time prolonged,apoptosis index (AI) of photoreceptor cells was elevated,among which the AI of 12h were (12.3±4.7)%and (32.4±6.2) % in Taurine and control group(P<0.05).The cfos mRNA of rat retina was transiently induced after one-hour light exposure and it was lower in taurine group (P<0.05);cfos protein level increased after three hour exposure and it was lower in taurine group (P<0.05).Conclusion Taurine can partly reduce the transcription and translation of c-fos,which would further inhibit the apoptosis signal transduction and protect the rat retina from photochemical damage.
Key words： taurine;photochemical damage;apoptotic cell;cfos
视网膜是视觉形成的重要组织结构，若光照时间或光照强度等超过视网膜承受力，则会导致光化学损伤〔1〕，损伤早期视功能减退，光感受器细胞丢失，后期内层神经元变性坏死，最终导致失明〔12〕。近年研究认为，凋亡是视网膜光化学损伤中光感受器细胞丢失的主要机制〔1,3〕，持续高强度光照使视网膜内自由基和脂质过氧化产物激增，同时氧化应激基因AP1表达上调促进凋亡信号转导，且证实其亚单位cfos是必需调控因子。牛磺酸与视网膜生长发育和功能维持关系密切，前期实验已证实，4％牛磺酸能有效保护光化学损伤条件下的大鼠视网膜〔4〕。本研究拟进一步观察其对光感受器细胞凋亡的影响，并从cfos表达变化角度探讨防护机制。
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