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 (P<0.05 or P<0.01)

and markedly up-regulated the expression of c-fos mRNA in retina (P<0.05 or P<0.01)

meanwhile

elevated the amount of c-fos positive cells (P<0.05 or P<0.01). 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.