糖尿病大鼠脑外侧膝状体神经元退行性变及APP17肽的作用

目的 通过观察糖尿病大鼠外侧膝状体神经元超微结构改变和神经元内凋亡相关因子Bax、Bcl-2、Cyto C的表达，证实糖尿病大鼠是否存在脑内视觉传导通路外侧膝状体神经元退行性改变，APP17肽对其是否有改善作用。方法 用链脲佐菌素(STZ)腹腔注射诱发糖尿病模型，10周后取脑组织行Bax、Bcl-2、Cyto C的免疫组化染色，同时取外侧膝状体处脑组织作电镜观察。结果 糖尿病组外侧膝状体腹侧核内Bax、Cyto C阳性反应神经元数目多、染色深，Bcl-2三组间无明显差异，APP17肽治疗组的Bax、Bcl-2、Cyto C的表达接近正常组。超微结构发现糖尿病组神经元有固缩、核膜凹陷、线粒体肿胀等退行性变，给予APP17肽后上述改变明显好转。结论 糖尿病大鼠发生了外侧膝状体神经元的退行性改变，神经元可能处于凋亡前状态；APP17肽可改善糖尿病大鼠外侧膝状体神经元的退行性改变。

Neurodegeneration of lateral geniculate body in diabetic rat and the effect of APP17-mer peptide

Objective To investigate the ultrastructure change of the lateral geniculate body in diabetic rat and expression of apoptosis-related protein (Bax ,Bcl-2, cyto C)as well as the effect of APP17 peptide on neurodegeneration of lateral geniculate body. Methods The experimental rats were divided into normal group(C group) ,DM group(D group) and APP17 peptide treating group (P group). Diabetic rat model were established by injection of streptozotocin into peritoneal cavity. APP-17 peptide were subcutaneously injected in P group , and their brain sections were prepared after 10 weeks of survival when water maze test was performed. The immunohistochemical staining of these section were then performed with Bcl-2, Bax, Cyto C antibody. Saline was injected in the rat of control group. Results Bax, Cyto C positive neurons in the ventral lateral geniculate body in D group rats numbered more than that of the C and P group significantly ( P < 0. 01 ). No markedly difference in the number of Bcl-2 positive neurons could be seen among the three groups. The ultrastructure of the lateral geniculate body in D group had abnormal changes and it could contain the integrity in P group. Conclusions There exists neurodegeneration in the lateral geniculate body in diabetic rat. APP17 peptide can improve the degenerative procedure.