实验性癫痫大鼠不同脑区的L-ENK表达及意义

Expression of Leu-Enkephalin in different cerebral regions of rats with pentylenetetrazol-induced epilepsy and its significance

目的采用戊四氮(PTZ)诱发大鼠癫痫,动态观察了部分脑区亮氨酸-脑啡肽(L-ENK)含量的变化,以探讨L-ENK与癫痫的关系。方法清洁级近交系雄性SD大鼠50只,分为对照组(A组,10只)及实验组(40只)。实验组按体重50mg/kg腹腔注射PTZ1次,对照组腹腔注射同等容量的生理盐水。根据癫痫发作分级,0￣1级7只为B组,立即取脑;2级以上发作33只,随机于癫痫发作后0h(C组,10只),6h(D组,11只),24h(E组,10只)取脑;最后剩下2只(F组)72h取脑。采用放射免疫方法,动态观察脑组织中海马、中脑、纹状体和额叶中L-ENK的改变;S-P免疫组化染色法染色,观察各组大鼠海马CA1区L-ENK的表达。结果发现应用PTZ后,癫痫大发作大鼠及未出现大发作的大鼠额叶、海马、中脑及纹状体中L-ENK含量均明显升高,两组间除中脑外无明显差异;但大发作大鼠的海马、中脑及纹状体L-ENK含量显著高于对照组。大发作后各脑区的L-ENK含量呈逐渐下降的过程。结论L-ENK可能参与了癫痫的发生过程。

Objective To probe into the relations between Leu-Enkephalin （L-ENK） and epilepsy by determining the expression level change of L-ENK in different cerebral regions of rats with pentylenetetrazol-induced epilepsy. Methods 50 healthy adult male SD rats were divided into experimental group and control group randomly. The rats in the experimental group were treated by injecting intraperitoneally PTZ （50 mg/kg）, and the rats of control group （group A, 10 rats） by injecting intraperitoneally equal amount of normal saline solution. According to the modification of seizure activity, the experimental group was sub-divided into seizure group and non-seizure group （group B, 7 rats）, which were decapitated immediately. The rats of seizure group were decapitated 0 h right after seizure （group C, 10 rats）, 6 h after seizure （group D, 11 rats）, 24 h after seizure （group E, 10 rats） and 72 h after seizure （group F, 2 rats）. RIA and Immunocytochemical technics were used to evaluate the changes of L-ENK in mesencephalon, hippocampus, striatum, and frontal cortex. Results After injection of PTZ, all seizure groups had an elevated level of L-ENK in mesencephalon, striatum, hippocampus and frontal cortex. No difference was found between non-convulsive group and convulsive group in the above four brain areas, but the L-ENK content ofhypothalamus in convulsive group was higher than that in non-convulsive group. After convulsion, the level of L-ENK decreased. Conclusion The LoENK at an increased level may play a role in epilepsy.