正常SD大鼠视网膜电图敏感度功能的发育

Functional development changes in electroretinographic sensitivity in the normal SD rats

目的纵向研究正常SD大鼠视网膜电图（ERG）敏感度功能的发育。方法实验研究。SD大鼠22只（22眼），分别在出生后16d、18d、（30±2）d和（64±2）d记录暗适应ERG。暗适应后用逐渐递增的自光刺激记录一系列的ERG。通过曲线拟合获得饱和a波波幅（Rmp3）和敏感度（S）。通过曲线回归获得最大b波波幅（Vmax）和敏感度（δ）。采用方差分析检验ERG参数在各时间点之间的差异。结果随着生长发育S和logδ逐渐增高。Rmp3在出生后18d时最高，以后随着生长发育逐渐下降。Vmax在出生后（30±2）d时最高，以后随着生长发育逐渐下降。结论ERG的敏感度随着生长发育而增高，反映了SD大鼠视杆细胞功能的发育特点。

Objective To evaluate the longitudinal development of electroretinographic （ERG） sensitivity in normal SD rats. Methods In an experimental study, scotopic ERGs of 22 eyes of 22 rats were recorded postnatally （P） on P16, P18, P30±2 and P64±2 days. The stimulus light was white with gradient intensities. Rod sensitivity （S） and the saturated a wave （Rmp3） were obtained by fitting Hood＇s function. Sensitivity of the b wave （tr） and maximum b wave （Vmax） were calculated by regression using the Naka-Rushton function. ANOVA was used to test the differences in ERG parameters at different postnatal ages. Results Both rod sensitivity （S） and b wave sensitivity （or） increased with development. The highest Rmp3 was obtained at P18 while Vmax occurred at P30±2 days. Conclusion Alteration of rod sensitivity increased with postnatal development and reflected the developmental characteristics of rod function of SD rat.