缺血后大鼠海马NR1 mRNA的表达及其与细胞凋亡的关系

目的：研究短暂性前脑缺血后大鼠海马NR1 mRNA的表达及其与细胞凋亡的关系。方法：以四血管阻断法建立脑缺血动物模型，采用原位杂交、TUNEL染色和图像分析等技术。结果：(1)在CA1区和CA3区，NR1 mRNA的表达于缺血后2h上升，24h达高峰，然后下降，但CA3区幅度明显较小；在齿状回，缺血后0．5～72h，表达无显著性变化，缺血后7d才显著降低。(2)TUNEL阳性细胞主要位于CAl区，于缺血后24h出现，至72h达高峰，然后有所减少。结论：大鼠短暂性前脑缺血后，NR1 mRNA的表达和细胞凋亡在海马各区存在显著性差异；提示缺血后NR1 mRNA的表达与海马的选择性易损性和缺血性细胞凋亡之间可能存在着某种联系。

Expression of NR1 mRNA in rat hippocampus following ischemia and its relationship with apoptosis

Objective: To study the alterations of NR1 mRNA expression and its relationship with apoptosis in hippocampus of rats following transient forebrain ischemia. Methods: Rats ischemia (15 min) reperfusion (0.5-7 d) (IR) model was created by four-vessel occlusion. In situ hybridization,TUNEL staining and image analysis system were used. Results: (1)In the CA1 region, the expression of NR1 mRNA increased obviously at IR 2 h and peaked at IR 24 h,then the expression started to decrease until IR 7 d. In the CA3 region, the pattern of NR1 mRNA expression was similar to that in the CA1 region, but the expression changed slightly. In the dentate gyrus, the expression of NR1 mRNA had no significant change during IR 72 h and dropped to the lowest on the IR 7 d. (2)At IR 24 h, the TUNEL positive cells appeared most in the CA1 region. Then they gradually increased and reached peak at IR 72 h. Afterwards,the positive cells started to reduce, but still existed on the IR 7 d. Conclusion: NR1 mRNA expression and cell apoptosis are different in different regions of hippocampus after IR. The unique alterations of NR1 mRNA expression might be responsible for the selective vulnerability and ischemic apoptosis in hippocampus after IR.