Sun Xiao-Nan, Zhang Jin-Song
Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Shenyang 110005, Liaoning Province, China.
Int J Ophthalmol. 2012;5(1):50-4. doi: 10.3980/j.issn.2222-3959.2012.01.10. Epub 2012 Feb 18.
Many studies have demonstrated N-methyl-D-aspartate receptor-1-subunit (NMDAR1) is associated with amblyopia. The effectiveness of levodopa in improving the visual function of the children with amblyopia has also been proved. But the mechanism is undefined. Our study was to explore the possible mechanism.
Sixty 14-day-old healthy SD rats were randomly divided into 4 groups, including normal group, monocular deprivation group, levodopa group and normal saline group, 15 rats each. We sutured all the rats' unilateral eyelids except normal group to establish the monocular deprivation animal model and raise them in normal sunlight till 45-day-old. NMDAR1 was detected in the visual cortex with immunohistochemistry methods, Western Blot and Real time PCR. LD and NS groups were gavaged with levodopa (40mg/kg) and normal saline for 28 days respectively. NMDAR1 was also detected with the methods above.
NMDAR1 in the visual cortex of MD group was less than that of normal group. NMDAR1 in the visual cortex of LD group was more than that of NS group.
NMDAR1 is associated with the plasticity of visual development. Levodopa may influence the expression of NMDAR1 and improve visual function, and its target may lie in the visual cortex.
许多研究已证明N-甲基-D-天冬氨酸受体1亚基(NMDAR1)与弱视有关。左旋多巴改善弱视儿童视功能的有效性也已得到证实。但其机制尚不清楚。本研究旨在探讨其可能机制。
将60只14日龄健康SD大鼠随机分为4组,即正常组、单眼剥夺组、左旋多巴组和生理盐水组,每组15只。除正常组外,将所有大鼠的单侧眼睑缝合以建立单眼剥夺动物模型,并在正常光照下饲养至45日龄。采用免疫组织化学方法、蛋白质免疫印迹法和实时荧光定量PCR法检测视皮质中NMDAR1的表达。左旋多巴组和生理盐水组分别给予左旋多巴(40mg/kg)和生理盐水灌胃28天。同样采用上述方法检测NMDAR1。
单眼剥夺组视皮质中NMDAR1的表达低于正常组。左旋多巴组视皮质中NMDAR1的表达高于生理盐水组。
NMDAR1与视觉发育可塑性有关。左旋多巴可能通过影响NMDAR1的表达来改善视功能,其作用靶点可能位于视皮质。