mGluR5对大鼠视网膜对光反应的调控  

Contribution of mGluR5 to different components of the rat dark-adapted electroretinogram

作　　者：戴加满[1] 何军材 李世迎[1] 阴正勤[1] 

机构地区：[1]第三军医大学西南医院眼科,重庆400038

出　　处：《中华眼视光学与视觉科学杂志》2017年第3期131-135,共5页Chinese Journal Of Optometry Ophthalmology And Visual Science

摘　　要：目的 探索代谢型谷氨酸受体5（mGluR5）对大鼠暗适应视网膜电图（ERG）不同成分的贡献。方法 实验研究。出生后30日龄大鼠（RCS-rdy＋-p＋）12只，暗适应大于12 h后，分别行视网膜下腔注射mGluR5激动剂CHPG[（R，S）-2-chloro-5-hydroxyphenylglycine] 200 μmol（6只，CHPG组）和抑制剂MPEP[2-methyl-6-（phenylethynyl）-pyridine] 200 μmol（6只，MPEP组），对侧眼注射同等体积PBS作为对照。注射后2 d采用RETI-scan系统记录其系列刺激光强度下（-4.5、-2.5、-0.5、-0.02、0.5 1 logcd×m×s-2）的暗适应ERG。导出数据，采用配对t检验进行双眼间数据比较。结果 CHPG组，a、b波幅值在不同光强下均显著降低（除最低光强）（-4.5〈t〈-2.3，P〈0.05），进一步分析得出a、b波最大幅值（Rmax和Vmax）均明显降低（-4.5〈t〈-2.3，P〈0.05），但其敏感度均未出现明显变化，且b/a未见明显变化。MPEP组，a、b波幅值在不同光强下均显著升高（除最低光强）（-3〈t〈-2，P〈0.05），进一步分析得出a、b波Rmax和Vmax均明显升高（-3〈t〈-2，P〈0.05），但其敏感度均未出现明显变化，且b/a未见明显变化。2组的振荡电位（OPs）与相应的对照眼比较未见明显差别。结论 mGluR5激动后，ERG a、b波幅值明显降低，mGluR5主要调控外层视网膜的对光反应。Objective To investigate the contribution of the metabotropic glutamate receptor 5 （mGluR5） to the different components of the rat dark-adapted electroretinogram （ERG）. Methods This was an experimental study. After 12 h dark adaptation, RCS-rdy＋-p＋ rats were subretinally injected with the 200 μmol agonist （R, S）-2-chloro-5-hydroxyphenylglycine （CHPG） and 200 μmol antagonist 2-methyl-6-（phenylethynyl）-pyridine （MPEP）. The same volume of phosphate buffered saline （PBS） was injected into the fellow eye for comparison. The dark-adapted ERGs were recorded by a series of flashes [-4.5, -2.5, -0.5, -0.02, 0.5, and 1 log（cd×m/s-2）]. Output data were exported and compared by paired t-tests. Results In the CHPG group, the amplitudes of the a- and b-waves at all light intensities （except the lowest intensity） were significantly decreased compared with the PBS-injected eyes. The parameters of Rmax and Vmax were also significantly decreased, but sensitivities of the a- and b-waves, the b-wave to a-wave ratio, and the oscillatory potentials （OPs） were unchanged when compared with the PBS-injected eyes. In the MPEP group, the amplitudes of the a- and b-waves at all light intensities （except the lowest intensity） were significantly increased compared with the PBS-injected eyes. The parameters of Rmax and Vmax were also significantly increased, but the sensitivities of the a- and b-waves, the b-wave to a-wave ratio, and OPs were unchanged when compared with the PBS-injected eyes. Conclusion The mGluR5 agonist CHPG decreased the amplitudes of the ERG a- and b-waves. This suggests that mGluR5 regulates the light responses of the outer retina.

关 键 词：MGLUR5 视网膜电图 CHPG MPEP 

分 类 号：R77[医药卫生—眼科]