左旋多巴甲酯对剥夺性弱视猫视网膜c-fos表达的影响

Effects of L-dopa Methyl Ester on the c-fos Expression in Retina of Monocular Deprivation Cats

目的:研究左旋多巴甲酯(LDME)对剥夺性弱视猫视网膜细胞凋亡情况以及c-fos表达及其分布的特点,并探讨其作用机制。方法:健康2周龄幼猫30只随机分成6组:模型对照组及正常对照组,左旋多巴阳性对照组,LDME低、中、高剂量组,每组5只。除了正常组,各组幼猫于4周龄时单纯缝合左眼建立剥夺性弱视,12周后打开缝合眼并开始给药,每天灌胃LDME 20,40,80 mg·kg-1,阳性组为左旋多巴40 mg·kg-1,正常组与模型组为等量生理盐水,持续30 d。TUNEL法检测视网膜细胞的凋亡情况,经原位杂交技术、免疫组化检测视网膜中c-fos mRNA和c-fos蛋白的表达。结果:与模型对照组比较,LDME明显减少弱视猫视网膜组织的细胞凋亡指数(P<0.05或P<0.01),显著上调c-fos mRNA在视网膜中的表达(P<0.05或P<0.01),同时增加c-fos免疫阳性细胞数量(P<0.05或P<0.01)。结论:左旋多巴甲酯有效地保护剥夺性弱视造成的视网膜损伤,其机制可能与抑制细胞凋亡以及促进c-fos表达有关。

Objective：To study the effects of L-dopa methyl ester（LDME） on the apoptotic cells the expression of c-fos mRNA,and c-fos positive cells in retina of monocular deprivation cats,then explore its mechanism on amblyopia.Method：Thirty normal cats were randomly divided into 6 groups（5 cats in each group）：low dose（LDMEL）,medium dose（LDMEM）,and high dose of L-dopa methyl ester（LDMEH）,positive control group（PC）,normal control group（NC） and model contro（MC）.The kittens in each group were visually deprived by suturing the lids of the left eyes to establish the monocular deprivation amblyopia,then eye was opened and treated with drug after 12 weeks.LDME（20,40,80 mg·kg-1）,L-dopa（40 mg·kg-1） and saline were given to the corresponding animals for 30 days.The TUNEL assay was used to detect apoptosis in retina,and the in situ hybridization and immunohistochemistry techniques were used to detect the expression of c-fos mRNA and c-fos protein.Result：Compared to the model control group,LDME significantly lessened the apoptotic index in retina（P0.05 or P0.01）,and markedly up-regulated the expression of c-fos mRNA in retina（P0.05 or P0.01）,meanwhile,elevated the amount of c-fos positive cells（P0.05 or P0.01）.Conclusion：Levodopa methyl ester can effectively improve the retinal damage caused by deprivation amblyopia,and the mechanisms may be linked to inhibiting apoptosis and up-regulating the expression of c-fos.