大鼠脑出血蛋白激酶C与细胞凋亡关系的实验研究

EXPERIMENTAL STUDY OF THE RELATIONSHIP BETWEEN PROTEIN KINASE C AND APOPTOTIC CELL IN RATS AFTER CEREBRAL HEMORRHAGE

目的:研究大鼠脑出血后血肿周围蛋白激酶C(Protein kinase C,PKC)及神经细胞凋亡的表达及其多黏菌素B(polymyxin B PMB)对上述表达的影响。方法:将100只SD大鼠随机分为四组:假手术组、脑出血组、小剂量多黏菌素B干预组(0.4mg/kg.d)、大剂量多黏菌素B干预组(0.8mg/kg.d),立体定位仪定位注射自体不凝血制造大鼠脑出血模型,分别为术后6h、12h、24h、72h、120h处死,免疫组织化学法检测血肿周围区PKC、TUNEL阳性细胞(凋亡细胞)数的表达、TNF-α(肿瘤坏死因子-α)含量、NO(一氧化氮)含量以及大小剂量PMB对其干预后的影响。结果:假手术组PKC少量表达,偶见凋亡细胞;脑出血组自6h起PKC、凋亡细胞及TNF-α、NO含量大量增加,72h达高峰,PKC在120h基本降至假手术组,但凋亡细胞TNF-α、NO含量仍处于较高水平,与假手术组比较差异有统计学意义(P<0.01);大小剂量多黏菌素B干预组均有明显抑制PKC、凋亡细胞、TNF-α含量的表达,有统计学意义(P<0.01);但PMB剂量的大小无明显差异性(P>0.05)。结论:脑出血后血肿周围存在大量PKC表达上调、神经细胞凋亡、TNF-α、NO含量增加,PMB能够明显抑制PKC激活,TNF-α、NO释放,减少血肿周围细胞凋亡,起到神经元保护作用。

Objective： To observe the expression of protein kinase C（PKC）,and the apoptosis of neuronal cell in rats after cerebral hemorrhage,and the influence of polymyxin B.Methods： 100 SD rats were randomly divided into sham operation group（n=25）,ICH group（n=25）,low dose polymyxin B treatment group（0.4mg/kg.d）（n=25）,and high dose polymyxin B treatment group（0.8mg/kg.d）（n=25）.Autologous blood was injected into the caudate nucleus of rat to produce cerebral hemorrhage model by stereotaxis instrument technique.Decapitation at 6h,12h,24h,72h,120h after the model was produced.PKC positive cell,TUNEL cell,TNF-α and NO contents were detected.Results： There was only a few PKC expression in sham operation group and the apoptotic cell（TUNEL positive cell）was difficult to observe.PKC isozyme,TUNEL cell,TNF-α and NO contents were great in intracerebral hemorrhage group at 6h,reached a high level at 72h,PKC positive cell descended to normal level at 120h,but they remained in higher level at 120h.There was statistical significance to compare with sham operation group（P〈0.01）;high or low dose polymyxin B was effective in containment of PKC positive cell,TUNEL cell,TNF-α and NO content’s express,and there was statistical significance（P〈0.01）.Conclusions： PKC,apoptotic cell,TNF-α and NO contents in the brian hematoma parenchyma markedly increased after ICH,polymyxin B can significantly reduce the activation of PKC,the mechanism may be related to inhibit the expression of PKC,reduce apoptosis cell around the hematoma,reduce release of TNF-α and NO,thereby it can protect neurons.