N-甲基-D-天冬氨酸受体1反义抑制剂治疗局灶性脑缺血作用机制的实验研究

目的 探讨N-甲基-D-天冬氨酸受体1（NMDAR1）反义抑制剂（ASODN）治疗急性脑梗死的作用机制。方法 采用Koizumi‘s线栓法制作可复流MCAO大鼠模型。40只8-12月龄健康，雄性Wistar大鼠随机分为4组；（1）MCAO组；（2）MCAO PBS组；（3）MCAO MSODN组；（4）MCAO ASODN组。实验各组分别于MCAO后2h,24h经侧脑室注射给药，MCAO后第5天处死动物。取脑组织进行NMDAR1免疫组织化学及NMDAR1mRNA原位杂交检测。检测结果经CMIAS图像分析系统进行定量分析。结果 （1）ASODN治疗组NMDAR1阳性细胞在海马CA1区，CA3区及DG区的数密度，光密度显著低于MCAO组；（2）ASODN治疗组NMDAR1mRNA阳性细胞在海马各区及大脑皮层的数密度，光密度与MCAO组无显著差异。结论 NMDAR1反义抑制剂可能主要作用于NMDAR1基因的蛋白翻译过程（胞浆机制），抑制缺血后神经元NMDAR1的产生。下调NMDAR1的数量及功能，减轻缺血后迟发性神经元坏死。达到脑保护作用。

Effects of antisense oligodeoxynucleotides on NMDAR1 in cerebral infarction in rats

Objective To investigate the effects of antisense oligodeoxynucleotides (ASODN) on NMDRR 1 in cerebral infarction in rats.Methods Reversible middle cerebral artery occlusion (MCAO) rats were induced with the intraluminal suture occlusion method created by Koizumi. 40 male Wistar rats, 280 to 380 g, were divided randomly into 4 groups:(1) MCAO group; (2) MCAO plus phosphate buffered saline (PBS) group; (3) MCAO plus missense oligodeoxynucleotide (MSODN) group; (4) MCAO plus ASODN group. The different drugs were injected intraventricularly at 2nd hour and 24th hour after MCAO in group B, C and D. The rats were sacrificed on 5th day after MCAO. Then NMDAR 1 immunchistochemistry and NMDAR 1 mRNA in situ hybridization were preformed. The numeral density (ND) and optical density (OD) of all positive neurons in hippocampus and cerebral cortex were measured by CMIAS image analysis system. The data were analyzed by SPSS 8.0 statistical software.Results (1) The ND and the OD of NMDAR 1 positive neurons in hippocampal CA 1, CA 3 or cortex in group D were greatly lower than that in group A, B or C; (2) The ND and the OD of NMDAR 1 mRNA positive neurons in hippocampus and cerebral cortex had no significant difference between group D and A. Conclusion The study suggested NMDAR 1 ASODN selectively inhibited the translation of NMDAR 1 and down regulated the expression of NMDA receptors, which could attenuate the neuron degeneration and play a brain protective role against ischemic injury.