血管性痴呆大鼠海马齿状回区D1受体的表达

Expression of dopamine D1receptors in hippocampal dentate gyrus in rats with vascular dementia

目的:观察血管性痴呆(VD)模型大鼠海马齿状回(DG)区的多巴胺(DA)浓度及D1受体表达情况,并探讨两者间的关系。方法:选用12只Sprague-Dawley雄性大鼠,随机分为VD组和假手术组,每组6只。利用双侧颈总动脉永久性结扎法制备VD大鼠模型,模型制备结束30d后,利用脑部微量透析法和高效液相色谱法测定海马DG区细胞外液中的DA浓度,应用免疫组织化学法观察海马DG区D1受体的表达情况。结果:VD组大鼠海马DG区细胞外液中的DA浓度较假手术组明显降低(P<0.05)。在VD组和假手术组大鼠的海马DG区颗粒细胞层均有D1受体的表达,2组间比较差异无统计学意义(P>0.05);而2组大鼠海马门区均有D1受体的表达,VD组D1受体表达水平明显升高(P<0.05)。结论:VD模型大鼠海马DG区的DA浓度减少,其功能可能是通过海马门区D1受体的表达增加而代偿的。

Objective To observe the extracellular content of dopamine （DA） and expression of D1 receptors in hippocampal dentage gyrus （DG） in the model rats with vascular dementia （VD）, and to investigate the relationship between them. Methods 12 male SD rats were randomly divided VD group and sham-operation group, and the VD model was prepared by permanent bilateral carotid occlusion. The extracellular content of DA in the DG was determined by in vivo microdialysis and HPLC, and the expression of D1 receptors was measured by immunehisto- chemistry. Results The DA content in the DG of the rats in VD group was lower than that in sham-operation group （P〈0.05）. The number of D1 receptor-positive cells in the DG hilus in VD group was increased compared with sham-operation group （P〈0.05）, whereas the expression of D1 receptor in DG granule cell layer did not change （P〉 0.05）. Conclusion The DA content in the hippocampal DG is decreased in the VD rats, and its function may be compensated by the up-regulation of D1 receptors in the DG hilus.