Opposing effects of atropine and timolol on the color and luminance emmetropization mechanisms in chicks.
Opposing effects of atropine and timolol on the color and luminance emmetropization mechanisms in chicks.
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DOI：
10.1016/j.visres.2016.03.001
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发表时间：
2016-05
期刊：
影响因子：
1.8
通讯作者：
Rucker FJ
中科院分区：
文献类型：
--
作者：
Goldberg LA;Rucker FJ
本研究分析了非选择性副交感神经阻滞剂阿托品和交感神经β受体阻滞剂噻吗洛尔对雏鸡的亮度和颜色正视化反应的影响。将小鸡双眼暴露（8小时/天）于三种照明条件之一四天：2 Hz正弦亮度闪烁、2 Hz正弦蓝色/黄色闪烁或稳定光（平均680勒克斯）。阿托品实验包括单眼每日注射20 μl阿托品（18 nmol）或20 μl磷酸盐缓冲盐水。噻吗洛尔实验涉及单眼每日应用2滴0.5%噻吗洛尔或2滴蒸馏水。在校正盐水/水处理的影响后，将实验眼的变化与对侧眼的变化进行比较。阿托品导致眼轴长度减少，同时伴有亮度闪烁（−0.078 ± 0.021 mm）和颜色闪烁（−0.054 ± 0.017 mm），玻璃体腔深度减少，伴有亮度闪烁（−0.095 ± 0.023 mm），引起屈光度远视偏移（3.40 ± 1.77 D）。噻吗洛尔导致眼轴长度增加，伴有亮度闪烁（0.045 ± 0.030 mm）和近视屈光偏移（−4.07 ± 0.92 D），而彩色闪烁导致眼轴长度显著减少（−0.046 ± 0.017 mm），与脉络膜变薄（−0.046 ± 0.015 mm）相关。阿托品和噻吗洛尔对生长和屈光的相反影响表明，通过亮度和颜色对比刺激视网膜，在副交感神经和β受体介导的交感神经系统之间存在平衡机制。
This study analyzed the luminance and color emmetropization response in chicks treated with the nonselective parasympathetic antagonist atropine and the sympathetic β-receptor blocker timolol. Chicks were binocularly exposed (8hr/day) for four days to one of three illumination conditions: 2 Hz sinusoidal luminance flicker, 2 Hz sinusoidal blue/yellow color flicker, or steady light (mean 680 lux). Atropine experiments involved monocular daily injections of either 20 μl of atropine (18 nmol) or 20 μl of phosphate-buffered saline. Timolol experiments involved monocular daily applications of 2 drops of 0.5% timolol or 2 drops of distilled H2O. Changes in the experimental eye were compared with those in the fellow eye after correction for the effects of saline/water treatments. Atropine caused a reduction in axial length with both luminance flicker (−0.078 ± 0.021 mm) and color flicker (−0.054 ± 0.017 mm), and a reduction in vitreous chamber depth with luminance flicker (−0.095 ± 0.023 mm), evoking a hyperopic shift in refraction (3.40 ± 1.77 D). Timolol produced an increase in axial length with luminance flicker (0.045 ± 0.030 mm) and a myopic shift in refraction (−4.07 ± 0.92 D), while color flicker caused a significant decrease in axial length (−0.046 ± 0.017 mm) that was associated with choroidal thinning (−0.046 ± 0.015 mm). The opposing effects on growth and refraction seen with atropine and timolol suggest a balancing mechanism between the parasympathetic and β-receptor mediated sympathetic system through stimulation of the retina with luminance and color contrast.