摘要
目的通过建立Müller细胞内谷氨酰胺合成酶损伤模型,探讨b波的时频域特征,检测谷氨酸代谢对b波时频域的影响。方法大鼠(Rcs-rdy!-p!)右眼注射4μL不同浓度(7、70、140μg/μL)的谷氨酸合成酶抑制剂(DL-AAA),左眼注射等计量PBS作为对照组。采用RETI-scan系统,环形角膜电极和不锈钢针状电极,记录18只30 d龄大鼠系列暗适应视网膜电图。导出数据后,在Matlab7.1环境下自编程序行小波分析。行配对样本t检验统计学分析。结果时域特征:随着DLAAA浓度的增加,a、b波的幅值降低。在低浓度时双眼间无统计学差异,中、高浓度实验组a、b波幅值较对照组均明显降低(P<0.05,P<0.01),而b波的峰时未见明显变化。高浓度时,b/a及T1/2d均出现明显变化。频域特征:在设定包络阈值为0.8时,归一化处理后发现,低浓度时最小环比基本重合,而随着药物浓度的增加,实验组最小环比则明显增高(P<0.05),且离散度增高,同时最高峰值的时间点后延(P<0.05)。结论抑制谷氨酰胺合成酶后,视网膜内谷氨酸代谢出现异常,该变化对b波的贡献在时域上体现为早期成分,在频域上体现为慢相低频成分,且对维持视网膜功能稳定性起到重要作用。
Objective To investigate the contributions of glutamate metabolism to electroretinogram( ERG) b-wave in time and frequency domains by wavelet transform in a glutamine synthetase( GS) inhibited rat model. Methods Different concentrations of glutamine synthetase inhibitor( DL-AAA) were subretinally injected into the right eyes of Rcs-rdy+-p+rats,and phosphate buffer solution was subretinally delivered into the left eyes as control. Dark-adapted ERG of all the rats was recorded with an RETI-scan system. A gold-foil ring cornea electrode was used as the recording electrode and a home-made stainless steel needle electrode was used as the reference electrode. The intensity of light ranged from-40 d B to 5 d B. Data were collected and analyzed with software Matlab7. 0,and students ’ t test was used for statistical analysis. Results The characteristics of time domain as follows: with the increase of DL-AAA concentration,the amplitudes of a-wave and b-wave were decreased. In the low concentration group,no any significant change was observed.However,the amplitudes had significant changes in the middle and high concentration groups as compared with the control group( P 〈 0. 05,P 〈 0. 01). Moreover,in the high concentration group,the parameters( b /a and T1 /2d) were changed dramatically. The characteristics of frequency domain as follows: when the envelope threshold was set at 0. 8,with the increase of DL-AAA concentration,the minimum ratio of circle increased and the dispersion increased( P 〈 0. 05). Meanwhile,the time of peak delayed( P 〈 0. 05).Conclusion The glutamate metabolism in the retina is disrupted after inhibiting GS in Müller cells,and this change contributes to the earlier part of ERG b-wave in the time domain and the slower part in the frequency domain,indicating that Müller cells play a major role in the stability of the retinal function.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2015年第12期1200-1203,共4页
Journal of Third Military Medical University
基金
国家自然科学基金青年科学基金(81200710)~~
关键词
谷氨酸代谢
谷氨酰胺合成酶
B波
小波分析
glutamate metabolism
glutamine synthetase
b-wave
wavelet analysis