急性心肌缺血期大鼠丘脑束旁核神经元5-HT1A受体mRNA表达变化的研究

目的 观察急性心肌缺血期大鼠丘脑束旁核神经元5-HT1A受体mRNA不同时间点表达的变化，以探讨5-HT1A受体在丘脑束旁核痛觉整合和调制中的作用。方法 健康成年雄性SD大鼠24只，随机分为四组：对照组，即非冠状动脉扎闭（C组）组，扎闭冠状动脉（coronary artery occlusion，CAO）1h组（CAO1h组），扎闭冠状动脉3h组（CAO3h组）和扎闭冠状动脉6h组（CAO6h组）。对照组仅在开胸后冠状动脉左前降支下穿线不予结扎；CAO各组则扎闭冠状动脉左前降支。在预定的时点处死动物，取含有大鼠丘脑束旁核的脑片行原位杂交。杂交结果检测采用IDA-2000数码显微图像分析系统进行半定量分析。结果 CAO后1、3、6h大鼠丘脑束旁核神经元5-HT1A受体mRNA的表达均较对照组明显增强（P〈0．05），随缺血时间延长其表达有逐渐增加的趋势，在CAO后6h表达最强（P〈0．05）。结论 急性心肌缺血可诱发大鼠丘脑束旁核5-HT1A受体mRNA表达增强，5-HT1A 受体参与急性心肌缺血伤害性刺激在丘脑束旁核的调制。

Study of the expression of 5-HT1A receptor mRNA of the neurons in parafascicular nucleus following acute myocardial ischemia in rats

Objective The purpose of this study was to investigate the changes in expression of 5-HT1A receptor mRNA in rat parafascicular nucleus(Pf)induced by coronary artery occlusion(CAO).Methods Twenty-four adult male SD rats randomly divided into four groups:group C:the control group,with non-CAO;group CAO 1 h:with CAO for 1 hour;group CAO 3 h:with CAO for 3 hours;group CAO 6 h:with CAO for 6 hours.Coronary artery was occluded except for group C.Rats were killed at scheduled time points,and then the brains were dissected in order to perform in situ hybridization(ISH)of brain tissue cryo-section.Brain slices of Pf were examined and analyzed semi-quantitively for expression of 5-HT1A receptor mRNA by using ISH technique with IDA-2000 digital micro-image analysis systems.Results The expression of 5-HT1A receptor mRNA in rat Pf increased significantly at 1 h,3 h and 6 h after CAO as compared with that in group C(P<0.05).The value was the highest at 6 h in group CAO 6 h(P<0.05).Conclusion Myocardial ischemia alone could cause the increase in the expression of 5-HT1A receptor mRNA of the neurons in rat Pf and it could serve as evidence showing that 5-HT1A receptor in Pf might be involved in central modulation of nociception evoked by acute myocardial ischemia.