戊四氮点燃大鼠中海马谷氨酸转运体的作用研究

Study on the role of glutamate transporter in hippocampus of the PTZ-kindled rats

目的 研究点燃形成过程中和点燃后谷氨酸转运体的变化 ,进一步探讨慢性癫痫的点燃机制。方法 将 78只雄性成年 Wistar大鼠随机分为对照组 ( 组 )和戊四氮 ( PTZ)组 ( 组 )。 组腹腔注射阈下剂量的 PTZ( 3 5mg/kg) ,每日 1次 ,直至达到点燃标准 ; 组腹腔注射等量生理盐水。采用逆转录聚合酶链式反应 ( RT-PCR)方法检测海马区谷氨酸转运体 -1 ( GLT-1 ) m RNA和兴奋性氨基酸载体 -1 ( EAAC1 ) m RNA的表达。结果 GL T-1m RNA的表达在 0 h、4 8h时显著升高 ,随后下降 ;EAAC1 m RNA的表达呈上升趋势。点燃后第 60 d时 ,基本恢复至对照组水平。结论 海马区 GLT-1的下降和 EAAC1的升高可能与癫痫敏感性的形成与维持有关。

Objective To investigate the mechanism of the enhanced seizure susceptibility by the change of GLT 1 and EAAC1 in hippocampus of the PTZ induced rats during and after kindling. Methods Seventy eight adult male Wistar rats(250～350g) were randomly divided into two groups, control group(Ⅰ) and PTZ group(Ⅱ). A dose of PTZ (35mg/kg/day) was intraperitoneally injected into the animals of group (Ⅱ) until the kindling criterion was reached. The rats of group(Ⅰ) were administered with the same dose of normal saline . The expression of GLT 1mRNA and EAAC1 mRNA in hippocampus were detected by the RT PCR.Results As compared with the controls, the expression of GLT 1mRNA started to increase at 15d after injection in PTZ group , and increased markedly at 0h, 48h after kindling ,then decreased significantly. The expression of EAAC1 mRNA was significantly increased after injection and kindling in PTZ group.They returned to the level of the controls at 60d. There was remarkable difference between the PTZ group and the controls after kindling. Conclusions The reduction of GLT 1 and the increase of EAAC1 in hippocampus can be related to seizure susceptibility.