腹腔注射MNU对大鼠视网膜结构与功能的影响  

Damage to structure and function of rat retina by intraperitoneal injec tion of MNU

作　　者：陈金卯[1] 杨锦南[2] 李岱[1] 罗琳[1] 江福钿[1] 胡世兴[1] 

机构地区：[1]中山大学中山眼科中心,广州510060 [2]新乡医学院药理室,河南省新乡市453003

出　　处：《眼科新进展》2004年第5期349-351,共3页Recent Advances in Ophthalmology

基　　金：国家自然科学基金资助 (编号 :30 30 0 4 67)~~

摘　　要：目的　探讨N 甲基 N 亚硝脲 (N methyl N nitrosourea,MNU)对大鼠视网膜的毒性作用。方法　生后 5 0d的雌性SD鼠 76只 ,随机抽取 4只为正常对照组 ,余 72只等分为 3组 ,分别按体重一次性腹腔注射MNU 5 0、4 0、30mg·kg-1。各组每次 4只分别于6、12、2 4、4 8h ,3、5d行闪光视网膜电图 (ERG)检查 ,并于造模 1、2、3、5、7、10d全麻后处死动物 ,取眼球做病理切片。结果　MNU 5 0、4 0、30mg·kg-1剂量组ERGa波消失时间分别为 6、12h ,3d ,b波消失时间分别是 12、2 4h ,5d。HE染色显示 :以中周部视网膜为观察对象 ,MNU 30mg·kg-1组第 3天开始出现外颗粒层结构改变 ,第 10天光感受器细胞显著减少 ,但未消失 ;MNU 4 0和 5 0mg·kg-1组第 1天即出现外颗粒层排列紊乱 ,外颗粒层消失时间前者在第 10天 ,后者在第 5天。所有模型切片结果 ,其神经节细胞层、内颗粒层以及色素上皮层与正常组相比均未见明显差异。结论　MNU能选择性地损伤视网膜光感受器细胞。Objective To investigate the poisonous effect o f N-methyl-N-nitrosourea(MNU)on the structure and function of rat retina.Methods Seventy-six female Sprague Dawley(SD)rats were used th roughout the study.Four of them were used as control.The other 72 rats were rand omly divided into 3 groups,24 rats in each group.Those animals were intraperitoneall y injected with MNU at different dosage of 50,40,30mg·kg -1 respectively.E ach time,4 rats of every group were detected by flash electroretinograms(ERG)at 6,12,24,48 hours,3,5 days after the injection.The rat s were pu t to death at 1 day,2,3,5,7,10 days after the injection.The eyeballs were immedi ately enucleated for histological observarion.Results The a-waves of ERG were vanished at 6,12 hours,3days a fter the injection of 50,40,30mg·kg -1 MNU,then the b-w aves,12,24 hours,5 days.The histological examination revealed that the outer nuc lear laye r(ONL)of the middle-peripheral retina changed with the dosage of MNU,whereas th e other structures of retina were kept unchanged.The ONL of the group of 30mg·k g -1 could be remained partly 10 days later and the group of 40,50mg·kg -1 which disappeared at 10,5 days,respectively.Conclusion The results demonstrated that MNU may selectively an d significantly damage the photoreceptor cells structurally and functionally.

关 键 词：N-甲基-N-亚硝脲 视网膜变性 视网膜电图 

分 类 号：R774.1[医药卫生—眼科] Q959.836[医药卫生—临床医学]