外源性脑源性神经营养因子对急性高眼压后大鼠视网膜磷酸化TrkB表达的影响

Expression of phosphorylated-TrkB receptor in rat retina following acute high intraocular pressure pretreated with BDNF

目的:检测脑源性神经营养因子(BDNF)干预对急性高眼压后大鼠视网膜磷酸化TrkB(p-TrkB)表达变化的影响。方法:成年大鼠随机分为单纯高眼压组、BDNF预处理高眼压组和溶媒预处理高眼压组,BDNF预处理高眼压组和溶媒预处理高眼压组动物左眼于加压前2d分别给予BDNF预处理或溶媒,右眼设为正常对照。各组动物左眼眼压升高至闪光视网膜电图b波消失的临界眼压并维持60min,动物分别存活1、3、7、14d后处死,冷冻切片行p-TrkB的免疫组织化学显色。结果:单纯高眼压组急性高眼压后p-TrkB的表达显著下调;溶媒预处理高眼压组实验结果与单纯急性高眼压组相似;BDNF预处理高眼压组p-TrkB的表达随再灌时间的延长进行性下调,但在各时间点的表达均显著高于单纯高眼压组。结论:外源性BDNF干预部分缓解了急性高眼压后视网膜p-TrkB表达的下调,对急性高眼压后的大鼠视网膜起到一定的保护作用。

Objective： To investigate the expression of p-TrkB in rat retina following acute high intraocular pressure （HIOP） with BDNF pretreatment. Methods ： Seventy-two adult rats were randomly divided into acute HIOP group, BDNF pretreated HIOP group and vehicle pretreated HIOP group. The left eyes of rats in BDNF pretreated HIOP group and vehicle pretreated HIOP group were injected with BDNF or vehicle respectively 2 days before HIOP. The intraocular pressure of all left eyes was increased until b wave of flash electroretinogragh （fERG） disappeared and such pressure maintained for 60 minutes. All the right eyes were served as normal control. The rats were sacrificed after a survival of 1, 3, 7 or 14 days. Immunohistochemistry was used to detect the expression of p-TrkB. Results ： Compared with the normal control group, the expression of p-TrkB was decreased significantly during reperfusion in the acute HIOP group. The expression of p-TrkB during reperfusion in the vehicle control group was similar to that in the acute HIOP group. In the BDNF pretreated HIOP group, the expression of p-TrkB was also decreased, but significantly higher than that in the acute HIOP group at all time points. Conclusion： Down-regulation of p-TrkB following HIOP was relieved by exogenous BDNF, which may be involved in the protection role of BDNF to the injuried retina following HIOP.