核因子-κB活性在大鼠脑水肿的变化及热休克反应对其影响的研究

摘要:

目的 研究核因子－κＢ（ＮＦ－κＢ） 在百日咳菌液致大鼠感染性脑水肿模型中的活性变化及热休克反应对其影响。方法 动物随机分为：①正常对照组（ＮＳ） ，②感染性脑水肿组（ＰＢ），③热休克处理组（ＨＳ＋ ＰＢ）。取左大脑半球全层脑组织分别测定脑组织含水量，干脑组织钠、钾离子含量；采用电泳迁移率改变法检测各组神经细胞核内ＮＦ－κＢＤＮＡ－ 蛋白结合物活性的变化并做密度扫描定量分析。结果 ＨＳ＋ ＰＢ各组脑组织含水量明显低于ＰＢ组（ Ｐ＜０ ．０１），ＨＳ＋ ＰＢ 各组Ｎａ＋ 含量明显低于ＰＢ组（Ｐ＜ ０．０１ 或Ｐ＜ ０．０５） ，Ｋ＋ 含量除２４ ｈ 之外，均明显高于ＰＢ组（ Ｐ＜０ ．０１） 。与正常对照组比较，２ ｈ 感染性脑水肿组ＮＦ－κＢ活性开始增加，并逐渐增高，以２４ ｈ 为最明显。热休克处理组各时相ＮＦ－ κＢ 活性均有不同程度减低。结论 大鼠感染性脑水肿时ＮＦ－ κＢ活性增加，热休克反应对大鼠感染性脑水肿的保护作用可能与抑制ＮＦ－κＢ的活性有关。

Abstract:

Objective The changes of nuclear factor-kappaB(NF-κB) activity in brain tissue of rats with infection brain edema were observed, and the effects of heat shock response (HSR) on the brain injury in this model were also evaluate. Methods Adult Sprague-Dawley rats were randomly divided into three groups: injection with pertussis bacilli (PB) suspension via the left internal carotid artery (PB), PB plus HSR pretreatment (HSR), and injection of normal saline instead of PB as normal control(NS). Water content(WC), sodium (Na +) and potassium (K +) concentrations in the brain tissue were measured. NF-κB complexes activity was detected using electrophoretic mobility shift assay(EMSA) in nuclear extracts of neurocytes. Results WC and Na + were significantly lower in HSR than in PB (P<0.01), while K + was higher in HSR than in PB (P<0.01) except at 24 hour. NF-κB was activated at 2,4,8 hours with a peak activity seen at 24 hour in NS. PB injection raised NF-κB activity, but the increase was markedly attenuated with HSR pretreatment. Conclusions The results suggest that HSR have some protective effects against PB-induced brain edema and that the protection seemed to be related to inhibiting augmentation of NK-κB activity.