虎纹捕鸟蜘蛛毒素对全脑缺血大鼠海马神经元细胞形态及bax、bcl-2 mRNA和蛋白表达的影响

目的:观察蛛网膜下腔注射虎纹捕鸟蜘蛛毒素(HWTX-I)对全脑缺血再灌注大鼠海马神经细胞线粒体和CA1区锥体细胞形态、凋亡相关因子bax和bcl-2 mRNA及蛋白表达的影响。方法:SD大鼠随机分为假手术组、生理盐水组及HWTX-I组,采用改良的Pulsinelli四血管阻断全脑缺血损伤结合蛛网膜下腔置管术模型,对大鼠海马神经细胞线粒体进行超微结构及Nissl染色形态学观察,免疫组织化学法检测Bax、Bcl-2蛋白表达,RT-PCR法检测baxb、cl-2 mRNA表达。结果:(1)HWTX-I能够使全脑缺血大鼠海马神经细胞线粒体基本维持正常形态。(2)HWTX-I能稳定全脑缺血大鼠海马CA1区锥体细胞分布。(3)HWTX-I能够下调全脑缺血再灌注大鼠海马组织bax mRNA及蛋白表达,上调bcl-2 mRNA及蛋白表达。结论:蛛网膜下腔注射HWTX-I对全脑缺血再灌注所致的大鼠海马神经元损伤有明显的保护作用。

The Effect of HWTX-Ⅰ on Morphology of Neurons and the Expression of Bax, Bcl-2 in the Hippocampus of Rats with Cerebral Ischemia

Objective The effects of huwentoxin-I(HWTX-I) on the mitochondrial morphology in the hippocampus neurons,Nissl stained hippocampus CA1 subfield pyramidal neurons,and the expression of apoptosis correlation factor bax,bcl-2 mRNA and protein during global cerebral ischemia of rats caused by reperfusion damage were oberved.Methods SD rats were randomly divided into the sham-operation group,the physiological saline group and HWTX-I 1.0μg/kg group.The model of modified Pulsinelli 4-vessal occlusion global cerebral ischemia combined with the method of placing anaesthesic tube into intrathecal space were used to observe the change in mitochondrial ultrastructure of neurons and CA1 pyramidal neurons stained with Nissl of the hippocampus,and to detect the expression of Bax,Bcl-2 protein and the expression of bax,(bcl-)2 mRNA through immunohistochemistry and RT-PCR respectively. Results During the global cerebral ischimia,HWTX-I could(1)maintain the normal mitochondrial configuration of hippocampus neurons of rats.(2)stabilize the distribution of hippocampus CA1 subfield pyramidal neurons.(3)decrease the expression of bax mRNA and protein in the hippocampus,and increase the expression of bcl-2 mRNA and protein in the hippocampus.Conclusion HWTX-I revealed significant neuroprotective effects on rats hippocampus neurons during global cerebral ischimia caused by reperfusion.