脑源性神经营养因子预处理后急性高眼压下大鼠视网膜TrkB的表达变化

目的：检测脑源性神经营养因子(BDNF)干预后大鼠视网膜TrkB的表达变化。为受损后视网膜节细胞的保护及外源性BDNF的应用提供一定的理论基础。方法：大鼠左眼分为急性眼高压及BDNF预处理组。使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60 min,分别存活1～14 d后处死,冰冻切片行尼氏染色及TrkB的免疫组织化学。结果：急性高眼压组各时间点节细胞层细胞数目均显著少于BDNF预处理组；1、3 d时TrkB的表达明显增加,7、14 d时则明显减少；BDNF预处理组在存活1、3 d时TrkB的表达明显增加,7 d时则下降至正常对照组水平,14 d时再次明显增加。结论：急性高眼压后大鼠视网膜内TrkB的表达存在时空变化,TrkB表达的上调提示视网膜对BDNF的需求增加。

Expression of TrkB in rat retina following acute high intraocular pressure induced by brain-derived neurotrophic factor

Objective:To investigate the expression of TrkB in rat retina following acute high intraocular pressure (HIOP) induced by brain-derived neurotrophic factor (BDNF).Methods:Forty-eight adult rats were randomly divided into acute HIOP group and BDNF pre-treated group.The left eyes of rats in BDNF pre-treated group were injected with BDNF 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.The right eyes served as a normal control group.The rats were sacrificed after 1,3,7 and 14 days.Nissl staining and immuno- histochemistry for detecting the expression of TrkB were used.Results:The arrangement of the retinal neurons was clearer and more regular in BDNF pre-treated group than that in HIOP group.Compared to the normal con- trol group,the expression of TrkB in HIOP group was significantly increased at day 1 and 3,then decreased gradually.The expression of TrkB in BDNF pre-treated group was similar to that in HIOP group at day 1 and 3, but restored to the level of the normal control group at day 7,and again significantly elevated at day 14.Conclu- sion:Temporal and spatial changes in the expression of TrkB occur in rat retina following acute HIOP.The up- regulation of TrkB expression suggests that more BDNFs are required in such a situation.