视网膜色素上皮变性大鼠随生长发育的视网膜电图改变

摘要

背景 RCS-rdy--P+大鼠随着生长发育会逐渐发生视网膜色素变性(RP),记录其生长发育过程中的视网膜电图(ERG)改变可为该模型鼠的进一步研究奠定基础.目的 观察RCS-rdy--P+大鼠视网膜发育过程中的ERG变化,研究ERG随发育的变化特点.方法 采用RETI-port系统、环形角膜电极和不锈钢针状电极分别记录生后21、32、37、45、60 d的RCS-rdy--P+大鼠的系列暗适应ERG,每个年龄组6只鼠.取相同时间点及数量的同种系正常的RCS-rdy+-P+大鼠作为正常对照.暗适应不同时间的ERG对比采用RCS-rdy+-P+生后60 d大鼠共9只,每组3只.结果在刺激光强、刺激频率、体温相同的情况下,RCS-rdy+-P+大鼠ERG b波振幅与暗适应时间有关,随着暗适应时间的延长,b波振幅增加,当暗适应时间超过12 h时,即使暗适应时间增加,b波振幅不再增长,说明暗适应超过12 h可以得到RCS-rdy+-P+大鼠一个较为稳定的ERG波形.与RCS-rdy+-P+大鼠比较,RCS-rdy--P+大鼠在生后21 d时ERG已出现a波、b波振幅的下降,同时隐含时明显延长,以a波改变为主.随着RCS-rdy--P+大鼠年龄增长及RP的进展,ERG a波、b波振幅进一步下降,隐含时延长,RCS-rdy--P+大鼠生后60 d时,其ERG反应记录不到.对照组大鼠在21 d时,ERG的a波、b波均振幅较低;生后32 d时RCS-rdy--P+大鼠b波振幅增加,但隐含时缩短;到生后45 d仅小幅增加,45-60 d再次出现b波振幅显著增加,隐含时缩短.结论 RCS-rdy--P+大鼠随着年龄的增长发生视网膜功能的变化,其暗适应ERG改变符合RP的进展过程.%Background RCS-rdy--P+ rat occur retinitis pigmentosa (PR) with the aging and development.To find OUt the retinal functional change using electrophysiological technique is useful for the further study of RCS-rdy--P+ rat. Ohjectlve The goal of this experiment was to investigate the dark-adapted electroretinogram (ERG) of RCS rats with aging. Methods The series of seotopic ERG were recorded in postnatal 21-,32-,37-,45-,60-day-old RCS-rdy--P+ rats respectively,and the age-matched RCS-rdy+-P+ rats were simultaneously recorded as control group.The ERG record was performed by a series of flash with RETI-scan system,gold-foil ring form cornea recording electrode and home-made stainless steel needle electrode.The use of animals complied with the Regulations of the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results Increase dark adaptation duration led to an ascended amplitude in ERG b-wave within 12 hours under the same light intensity,frequency and body temperature.Compared with the RCS-rdy+-P+ rats,the amplitudes of scotopic ERG a-wave and b-wave in RCS-rdy--P+ rats with postnatal 21 days age were apparently declined,showing significant difference between them(P<0.01).The implicit time of both RCS-rdy+-P+ rats and RCS-rdy--P+ rats were delayed, especially for the a-wave. The amplitudes of a-wave and b-wave were declined drastically with the growth of RCS-rdy--P+ rats and progression of their retinal degeneration, and the ERG responses were undetectable at the postnatal 60 days. Both the b-wave and a-wave amplitudes were lowered at P21-day RCS-rdy+-P+ rats and after that,significant increase amplitudes were noted till the P32-day rats. Thereafter, the b-wave amplitude and a-wave amplitude were stable from P32 d to P45 d,and much more ascending of b-wave and a-wave amplitudes was at P60 d RCS-rdy+-P+ rats. Conclusion RCS-rdy--P+ rats occur the retrogression of retinal function along with the ages growth. The scotopic ERG changes of RCS-rdy--P+ rats with aging is evidently different and is in accordance to the characteristics of the RP.