甲状腺激素转运体MCT8在2VO大鼠脑组织中的表达

摘要

目的 探讨2VO大鼠脑组织中甲状腺激素转运体MCT8在不同缺血时间点基因水平的变化规律.方法 25只成年雄性SD大鼠随机分为正常对照组、2VO 3 d组、2VO 2周组和2VO 5周组.采用免疫荧光法观察MCT8在正常大鼠侧脑室中的表达；采用双侧颈总动脉永久性结扎术制备脑缺血模型,术后各组大鼠于实验终点采用荧光定量PCR法测定脑组织中甲状腺激素转运体MCT8 mRNA的表达水平.结果 免疫荧光法观察到MCT8在正常大鼠侧脑室的血管内皮细胞膜上表达丰富；中枢甲状腺激素转运体MCT8 mRNA水平在2VO 3 d组及2VO 2周组与正常组相比较差异无统计学意义(P=-0.909,P=0.694)；MCT8 mRNA水平在2VO 5周组较正常组及2VO 3 d组明显增高(P＝0.029,P=0.023),与2VO 2周组相比较差异无统计学意义(P=0.065).结论 中枢甲状腺激素转运体MCT8基因水平在脑缺血后呈逐渐代偿性增高趋势.%Objective To investigate the mRNA expression of monocarboxylate transporter 8 (MCT8),a thyroid hormone transport protein,in the lateral ventricle of rats with cerebral ischemia.Methods Immunofluorescence staining was used to observe the expression of MCT8 in the lateral ventricle of 5 normal SD rats.Another 20 adult male SD rats were randomized into 4 groups and subject to permanent ligation of both the common carotid arteries (2-vessel occlusion,2VO) for 3 days,2 weeks,or 5 weeks,or no ligation (control).At the end of the experiment,the transcriptional level of MCT8 in the brain tissue of the rats were detected using fluorescent quantitative PCR.Results MCT8 mRNA levels in 3-day and 2-week 2VO groups were comparable with that in the control group (P=0.909;P=0.694),but increased significantly in 5-week 2VO group compared with that in the control and 3-day 2VO groups (P=0.029;P=0.023).No significance was found in MCT8 mRNA between the 2-week and 5-week 2VO groups (P=0.065).Conclusion Prolonged cerebral ischemia causes compensatory increase of MCT8 mRNA expression on the capillary endothelial cell membranes in the lateral ventricle of rats.