两种病因弱视幼猫视网膜中NOS和GABA的表达

Expression of nitric oxide and γ-aminobutyric acid in the retina of two kinds of amblyopia cats

目的:分别利用单眼睑缝合法和外直肌离断法建立两种不同病因的幼猫弱视模型,探讨一氧化氮(NO)和γ-氨基丁酸(GABA)这两种神经递质在两种弱视形成过程中的作用。方法:3周龄幼猫18只,随机分为正常组、形觉剥夺组、斜视组,利用单眼睑缝合法和外直肌离断法建立两种病因的幼猫弱视模型,12wk后行图形视觉诱发电位检测。摘取眼球做病理切片,使用免疫组化染色法检测两组弱视眼和正常组视网膜中NOS和GABA的表达。结果:形觉剥夺组、斜视组12wk与同龄正常组图形视觉诱发电位(P-VEP)比较,均可见P1波潜伏期延长、振幅下降,差异有统计学意义(P<0.05)。弱视组视网膜内的NOS和GABA免疫阳性神经元染色淡,平均阳性面积减少,与同龄正常组相比差异有统计学意义(P<0.05)。弱视组间视网膜中的NOS和GABA平均阳性面积差异无统计学意义(P>0.05)。结论:NO和GABA的水平降低可能导致弱视眼视网膜内神经兴奋性的改变,二者在弱视形成过程中起着重要作用。

AIM： To study the role of nitric oxide （ NO ） and γ-aminobutyric acid （ GABA） in the formation of amblyopia by establishing 2 different types of amblyopic models.METHODS：A total of 18 aged 3-week kittens were randomly divided into monocular deprivation, strabismus and normal groups. All types of amblyopia were developed in the experimental eyes that were detected by P-VEP 12wk later. The cats were killed and the immunocytochemistry staining method were applied to observe under the light microscope the changes of distribution and positive cells areas of NO and GABA across the amblyopic retinal, compared to that from the normal cats of identical age. RESULTS： The P-VEP showed that the amplitude of wave P1 was lower （P〈0. 05） and the P1 latent time was longer （ P〈0. 05 ） in two types of amblyopic cats than those in the normal cats. Compared to the normal cats, the NO and GABA positive cells areas were obviously reduced （ P〈0. 05 ） across the retina in the amblyopic cats. But no significant difference was found between two kinds of amblyopic cats. CONCLUSION：The NO and GABA play an important role in the formation of amblyopia in the level of retinal.