戊乙奎醚预先给药对大鼠急性肺损伤时NF-κB的影响

目的 探讨戊乙奎醚预先给药对大鼠急性肺损伤(ALI)时NF-κB的影响.方法 雄性SD大鼠35只,体重210～280 g,随机分为5组(n=7):对照组(C组)、ALI组和低、中、高剂量戊乙奎醚组(P1-3组).采用经尾静脉注射内毒素5 mg/kg的方法建立大鼠ALI模型.C组和ALI组经腹腔注射生理盐水0.5 ml,P1～3组分别经腹腔注射戊乙奎醚0.03、0.1和3 mg/kg,30 min后ALI组、P1～3组制备AU模型,C组不制备模型.于静脉注射LPS后4 h时,行血气分析,计算氧合指数;称量肺组织湿重(W)、干重(D),计算W/D;采用比色法测定肺组织髓过氧化物酶(MPO)活性;采用RT-PCR法测定肺组织肿瘤坏死因子-α(TNF-α)mRNA、白细胞介素-1β(IL-1β)mRNA的表达水平;采用ELISA法测定肺组织TNF-α和IL-1β的含量;采用非放射性EMSA法测定肺组织NF-κB活性;采用免疫组织化学法测定肺组织NF-κB的表达水平.结果 与C组比较,其余各组氧合指数降低,肺组织W/D和MPO活性、TNF-α,IL-1β含量及其相应mRNA表达水平、NF-κB活性和表达水平均升高(P<0.05或0.01);与ALI组比较,P1～3组氧合指数升高,肺组织W/D和MPO活性降低,TNF-α、IL-1β含量及其相应mRNA表达水平降低,NF-κB活性和表达水平降低(P<0.05);P1～3组上述指标比较差异无统计学意义(P>0.05).结论 戊乙奎醚预先给药减轻大鼠急性肺损伤的机制可能与抑制NF-κB的活化,下调NF-κB的表达,降低肺组织炎性反应有关.

Effects of penehyclidine pretreatment on nuclear factor kappa B activation during acute lung injury in rats

Objective To investigate the effects of penehyclidine (PHCD) pretreatment on nuclear factor kappa B (NF-κB) activation during acute lung injury (ALI) induced by lipopolysaccharide (LPS). Methods Thirty-five male SD rats weighing 210-280 g were randomly divided into 5 groups (n= 7 each) : group Ⅰ control (C); group Ⅱ ALl; group Ⅲ, Ⅳ,Ⅴ received intraperitoneal (IP) PHCD 0.03, 0.1 and 3.0 mg/kg at 30 min before intravenous LPS. ALI was induced by intravenous LPS 5 mg/kg via tail vein in group Ⅱ- Ⅴ . Normal saline (NS) was given instead of LPS in group Ⅰ . The animals were anesthetized with LP 10% chloral hydrate at 4 h after intravenous LPS. Blood samples were taken from abdominal aorta for blood gas analysis,and PaO2/FiO2 was calculated. The animals were then killed by exsanguination and the lungs were removed for determination of MPO activity in the lung tissue (by colorimetry), W/D lung weight ratio and microscopic examination. Lung homogenate, was prepared for determination of NF-κB activity (by EMSA), expression of TNF-α and IL-β mRNA (by RT-PCR) and protein (ELISA). Expression of NF-κB p65 in the lung tissue was determined by immuno-histochemical staining. Results Compared with control group, PnO2/FiO2 was significantly decreased, while W/D, MPO activity, TNF-α and IL-β mRNA expression and contents and NF-κB activity and protein expression in the lung tissue were significantly increased during ALI induced by LPS in group Ⅱ (P<0.05 or 0.01 ). PHCD pretreatment significantly attenuated the LPS-induced changes in the lung mentioned above in group Ⅲ-Ⅳ. There was no significant difference in the indices mentioned above among group Ⅲ-Ⅴ. Conclusion PHCD pretreatment can ameliorate LPS-induced ALI through inhibition of NF-κB activation and inflammatory response of lung tissue.