Effects of L-dopa methyl ester on the strabismic amblyopia cats / 中国药理学通报

ABSTRACT

Aim To observe the effects of the L-dopa methyl ester (LDME) on the pattern visual evoked potentials (P-VEP) and the expression of c-fos mRNA in neurons of the visual cortex of kittens with strabismic amblyopia, and explore the therapeutic effect of L-dopa methyl ester on amblyopia and its action mechanism.Methods 30 normal kittens were randomly divided into 6 groups low dose of L-dopa methyl ester (20 mg·kg~(-1)), medium dose of L-dopa methyl ester (40 mg·kg~(-1)), and high dose of L-dopa methyl ester (80 mg·kg~(-1)),positive control (L-dopa 40 mg·kg~(-1)),normal control, and model control group.The surgery for producing iatrogenic convergent strabismus was performed on 4 weeks old kittens(normal control group excluded). After the confirmation of the development of amblyopia by pattern visual evoked potential,L-dopa methyl ester,L-dopa and normal saline were given to the corresponding animals, respectively. The P-VEP of amblyopia eyes was observed after one month, and the technique of in situ hybridization was used to detect the expression of c-fos mRNA.Results L-dopa methyl ester could reduce obviously the length of P100 peak latency of the cat strabismic amblyopes, and increase the amplitude of P100. The positive staining cells of strabismic cat visual cortex were less than those of normal cats, whose difference was significant (P<0.01).Positive staining cells in the treatment group were significantly increased when compared with that of the model group (P<0.01).Conclusion L-dopa methyl ester can significantly improve the conduction and sensory function in the model of strabismic amblyopia cats. The mechanism may be related to the increased amount of L-dopa methyl ester into the cerebral cortex and regulation of the expression of c-fos mRNA.