吡咯烷二硫代氨基甲酸盐对脓毒症大鼠急性肺损伤的保护作用及机制

Protective effects and mechanism of pyrrolidine dithiocarbamates on acute lung injury of LPS-induced septic rats

目的研究脂多糖(lipopolysaccharide,LPS)所致急性肺损伤(acute lung injury,ALI)的病理过程,探讨吡咯烷二硫代氨基甲酸盐(pyrroli dinedithiocarbamates,PDTC)对LPS所致ALI的保护作用及机制。方法96只SD雄性大鼠分为对照组、模型组,PDTC预防组。静脉注射LPS(6mg/kg)复制ALI动物模型,分别于注射后2、4、8、12h活杀。PDTC预防组在注射LPS前30min予以PDTC(120mg/kg)腹腔注射。测定肺湿/干质量比(W/D),石蜡包埋切片经HE染色行肺组织病理评分,TUNEL法测肺泡巨噬细胞(alveolar macrophages,AM)凋亡率,免疫组化法检测核因子-κBp65(nuclear factor-κBp65,NF-κBp65)表达,RT-PCR法检测AM的sPLA2ⅡA、Bcl-2、Bax基因的表达。结果与对照组比较,模型组肺W/D、肺组织病理评分、AM的NF-κBp65表达及凋亡、AM的sPLA2ⅡA基因表达增加(P<0.05),AMBcl-2、Bax基因的表达下降(P<0.05)。与模型组比较,PDTC预防组上述改变得以逆转,肺损伤程度明显减轻(P<0.05)。结论预防性予以PDTC可抑制AMNF-κB活化,抑制sPLA2ⅡA基因表达,促进Bcl-2基因表达,抑制AM凋亡,对LPS所致的ALI有一定的保护作用。

Objective To investigate the pathological process of lipopolysaccharide （ LPS） -induced acute lung injury （ ALI） in rats,and to explore the protective effects and mechanisms of pyrrolidine dithiocarbamates （ PDTC） on it. Methods Ninety-six SD male rats were randomly assigned into 3 groups： control group,model group,PDTC prevention group. ALI was induced by intravenous injection of LPS （ 6 mg/kg） ,and then these animal were respectively killed in ,4,8 and 12 h after LPS injection. The rats from PDTC prevention group were given PDTC （ 120 mg/kg） by intraperitoneal injection in 30 min before the LPS injection. The lung wet/dry weight ratio was calcuated,lung pathology was observed with hematoxylin and eosin （ HE） staining, alveolar macrophages （ AM） apoptosis ratio with TUNEL method,nuclear factor-κBp65 （ NF-κBp65） expression with immunohistochemical staining,and mRNA expressions of secretory phospholipase A2 typeⅡA （ sPLA2 ⅡA） ,Bcl-2 and Bax with RT-PCR. Results Compared with control group,the lung wet/dry weight ratio, lung pathologic tissue score,AM apoptosis ratio,AM NF-κBp65 expression,and sPLA2 ⅡA expression were increased,and AM Bcl-2 expression was decreased in model group （ P〈0. 05） . These changes were inverted in rats of PDTC prevention group,and the degree of lung injury was markedly attenuated （ P〈0. 05） . Conclusion The prophylactic PDTC administration potentially exerts protective function in LPS-induced ALI rats, probably through inhibiting the activation of NF-κB,decreasing the expression of sPLA2 ⅡA while increasing Bcl-2 expression in AM,and thus suppressing AM apoptosis.