摘要
目的研究大鼠脑缺血后水通道蛋白4（aquaporin-4，AQP-4）的表达水平及甘露醇对其影响。
方法构建大脑中动脉闭塞模型，随机分为甘露醇治疗小剂量组（0．5g／kg）（n=32）、大剂量组（1．0g／kg）（n=52）和对照组（n=32），于梗死后6n、12h、1d、3d各时间点随机抽取5只大鼠处死；另设假手术组5只。取脑组织分别作含水量、血脑屏障通透性测定（以伊文思蓝为示踪剂）及采用逆转录-聚合酶链反应（reverse transcription—polyrnerase chain reaction，RT—PCR）分析AQP4信使核糖核酸（Messenger ribonucleic acid，mRNA）的表达水平。
结果小剂量组、大剂量组及对照组缺血侧脑组织含水量在梗死后上升，3d到达高峰（P〈0．05），各组间差异无统计学意义（P〉0．05）；小剂量组、大剂量组及对照组缺血侧脑组织伊文思蓝含量在梗死后上升，1d到达高峰（P〈0．05），各组间差异无统计学意义（P〉0．05）；对照组缺血侧梗死灶周围皮质AQP-4 mRNA表达水平在梗死后1d到达高峰，5d开始回降，但仍处高水平（P〈0．05），小剂量组、大剂量组与对照组相比显著降低（P〈0．05），小剂量组与大剂量组相比差异无统计学意义（P〉0．05）。
结论大鼠缺血性卒中后缺血侧梗死灶周围皮质AQP-4 mRNA表达水平动态变化规律提示，AQP4与脑水肿的发生发展密切相关；甘露醇可明显降低缺血侧梗死灶周围皮质AQP-4 mRNA表达水平，提示甘露醇对AQP-4有抑制作用。
Objective To study the aquaporin-4（AQP-4） expression after cerebral ischemia and the effect of mannitol on AQP-4.
Methods The middle cerebral artery thrombosis model were established, randomly divided into three groups, low dose mannitol group （0.5g/kg, n=32）, high dose mannitol group（1.0g/kg, n=32）and control group （n=32）, and 5 rats were randomly decapitated at the time points of 6h, 12h, ld and 3d after cerebral ischemia （n=5 in each group）. Meanwhile, we also establish sham group （n=5）. Brain tissues were taken, the brain water content and permeability of Blood-brain Barrier were detected （Evans blue as a tracer）, reverse transcription-polyrnerase chain reaction （RT-PCR） were used to detect the expression of AQP-4.
Results In low dose group, high dose group and control group, brain water content in ischemic tissues increases after cerebral ischemia, and reaches 3d as the highest point （P〈0.05）, no significant differences is observed among groups（P〉0.05）; In low dose group, high dose group and control group, the Evans Blue in ischemic tissues increases after cerebral ischemia, and reaches ld as the highest point （P〈0.05）, no significant differences between groups（P〉0.05）; In control group, the expression of AQP-4 mRNA in peri-ischemic cortex reaches ld as the highest point, then declines at 3d, but still at high level（P〈0.05）; and there is a significant difference with low dose group and high dose group （P〈0.05）, no significant differences between low dose group and high dose group（P〉0.05）.
Conclusion The dynamic change regulation of expression ofAQP-4 mRNA in rat peri-ischemic cortex after cerebral ischemia suggest that AQP-4 is closely related to the occurrence and development of cerebral edema; mannitol can significantly reduces the expression of AQP-4 mRNA in peri-ischemic cortex, and that mannitol is a disincentive for AQP-4.
出处
《中国卒中杂志》
2009年第5期370-375,共6页
Chinese Journal of Stroke
