大鼠局灶性脑缺血再灌注后早期生长反应基因-1 mRNA的表达

目的探讨早期生长反应基因-1( early growth response gene-1,Egr-1)mRNA在大鼠局灶性脑缺血再灌注后的表达情况。方法取10只健康雄性SD大鼠,体重200 ～250 g,应用原位杂交和RT-PCR方法检测大鼠局灶性脑缺血再灌注后Egr-1 mRNA的表达情况。结果 (1)原位杂交结果:假手术组神经元及胶质细胞为轻度阳性表达。缺血2 h再灌注2 h后,缺血侧Egr-1 mRNA细胞阳性表达明显增强。再灌注4 h时Egr-1 mRNA细胞阳性表达最高,再灌注22 h Egr-1 mRNA细胞阳性表达下降,至166 h时下降更加明显,但仍显著高于假手术组。(2)RT-PCR结果:大鼠脑缺血再灌注后缺血侧Egr-1 mRNA的表达明显高于假手术组,P<0.01。动态观察发现,脑缺血2h再灌注2 h后,Egr-1 mRNA即高表达,缺血2 h再灌注4 h达高峰,再灌注46 h已明显下降,但仍高于假手术组,P<0.01,随缺血再灌注时间延长,Egr-1 mRNA表达又逐渐增多,至再灌注166 h其表达亦明显高于假手术组,P<0.01。结论缺血再灌注后Egr-1 mRNA有规律性表达。

The expression of the early growth response gene-1 after focal cerebral ischemia/reperfusion in rats

Background To investigate the expression of the early growth response gene-1 ( Egr-1 ) mRNA after focal cerebral ischemia / reperfusion in rats.Methods Ten healthy male SD rats weighing 200 ～ 250 g were used to create model of focal cerebral ischemia. The expression of Egr-1 after focal cerebral ischemia/reperfusion in rats was determined using in situ hybridization and RT-PCR.Results (1) The result of the in situ hybridization: A trace amount of Egr-1 mRNA expressed in the neurons and the glial cells in the sham operated group. The expression of Egr-1 mRNA at the ischemic side increased dramatically following ischemia and reached peaks after 4 hours' reperfusion. Egr-1 expression started to subside following 22 hours' reperfusion and further decreased following 166 hours' reperfusion, which was still significantly higher than that in the sham operated group. (2) The result of RT-PCR: The expression of Egr-1 mRNA at the ischemic side was significantly higher than that in the sham operated group at all time points after ischemia/reperfusion in the rats(P ＜0. 01). Expression of Egr-1 increased 2 h after ischemia and reached the peak 4 h following reperfusion, and then decreased dramatically at 46 h after reperfusion which was still higher than that in the sham operated group (P ＜ 0. 01). As the ischemia/reperfusion period prolonged, the expression of Egr-1 mRNA increased gradually, but still detectable even 166 h following reperfusion. The expression of Egr-1 was significantly higher than that in the sham operated group at all time points (P ＜0. 01).Conclusions The expression of Egr-1 mRNA increase in the neurons and the glial cells after ischemia/reperfusion, which may have protective effects on ischemic brain tissues.