人参二醇组皂苷对内毒素休克大鼠心肌组织CD14、IkB和NF-κ B p65表达的影响

CD14, IkB and NF-κB p65 expression in myocardium effected by panaxadiol with endotoxic shock in rats

目的通过观察内毒素诱导的休克大鼠心肌CD14、核因子-κB抑制蛋白(IκB)和核因子-κB亚基p65(NF-κB p65)的表达变化,探讨人参二醇组皂苷(panaxadiolsaponin,PDS)对休克大鼠心肌保护作用的相关机制。方法 40只Wistar大鼠分为空白对照组(CTR)、内毒素休克模型组(LPS)、地塞米松治疗组(DEX)和人参二醇组皂苷治疗组(PDS)。LPS(5 mg/kg)舌下静脉注射复制休克模型,当动脉血压降至初始血压的2/3时作为判定休克的标准。记录不同时间段平均动脉压(mean arterial pressure,MAP),各组大鼠分别于休克后2 h和4 h测定血清谷草转氨酶(aspartate aminotransferase,AST)、肌酸激酶(creatinekinase,CK)和乳酸脱氢酶(lactate dehydrogenase,LDH)活性,采用R T-PCR方法检测心肌组织CD14和IκB mR NA水平,Western blotting检测CD14和NF-κBp65蛋白质表达水平。结果各组大鼠注入LPS 5min后进入休克状态,并在10min后MAP代偿性回升,但LPS组从休克第45 min MAP进行性下降,而PDS和DEX组在LPS组进入可逆性失代偿阶段后,仍维持代偿性变化;LPS组血清中AST、CK和LDH活性最强,PDS及DEX组酶活性明显低于LPS组(P<0.05);R T-PCR结果显示,LPS组IκB mR NA表达明显减弱,CD14 mR NA表达增强,给予DEX治疗后IκB和CD14 mRNA表达均降低;给予PDS治疗后IκB mRNA表达较LPS组明显增高,而CD14表达明显降低;Western blotting证实,LPS组CD14及NF-κB表达明显增高,给予DEX和PDS治疗后CD14和NF-κB表达受到抑制,其表达量接近CTR组。结论 PDS对休克大鼠心肌具有保护作用,能减轻内毒素血症时心肌表达CD14、IκB和NF-κB p65。

[Objectives] To observe CD14, IkB and NF-κB p65 expression changing in myocardium induced by lipopolysaccharide and explore the protective effect of PDS on myocardium with endotoxic shock in rats. [Methods] 40 healthy W/star rats were divided into 4 groups： the control group （CTR）, the lipopolysae charide endotoxic shock model group （LPS）, dexamethasone group （DEX） and panaxadiol group （PDS）. LPS （5 mg/kg） was sublingually administered intravenously to build up endotoxic shock model. It was called shock when the mean arterial pressure （MAP） decreased to 2/3 of normal blood in rats. MAP was monitored at dif- ferent time, AST, CK and LDH activities in serum were detected after shock for 2 h and 4 h respectively. CD14 and IKB mRNA expression in myocardium was detected with RT-PCR and CD14 and NF-κB p65 pro- tein expression with Western blotting. [Results] It was found by dynamic observation that the rats entered in- to shock state at 5 rain treated with LPS, MAP had an compensatory restoration at 10 rain of shock, in LPS group, MAP fell progressively since 45 min of shock until the models got close to death at 4 h, however MAP remained steady and constant compensatory changes in PDS and DEX groups until the rats were killed at 4 h; Three kinds of myocardial enzymes （AST, CK and LDH） in PDS group were highest among groups, but in PDS and DEX groups they were lower, P 〈0.05. IkB mRNA and expression level decreased while CD14 mRNA increased in group LPS. In group DEX IKB and CD14 mRNA levels were inhibited while in group PDS IKB mRNA expression was enhanced but CD14 mRNA decreased compared with LPS. Western blot analysis identified that CDI4 and NF-κB protein levels were increased in group LPS while both were in- hibited in groups DEX and PDS. [Conclusion] PDS had protective effect against myocardium injury of endo- toxic shock in rats and decreased expressions of CD14, IKB and NF-κB p65 of myocardium.