赤芍对大鼠内毒素性急性肺损伤保护作用机制的研究

目的　探讨赤芍 (RPR)对大鼠内毒素性急性肺损伤 (ALI)保护作用的机制。方法　采用大鼠内毒素ALI模型。 4 0只Wistar大鼠随机分为生理盐水对照组 (NS组 )、内毒素组 (LPS组 )、赤芍治疗组 (RPR1组 )、赤芍预防组 (RPR2 组 )和i NOS阻滞剂氨基胍组 (AG组 )。观察组织病理以及生物学标志 :肺湿 /干重比、肺泡灌洗液中性粒细胞比、蛋白含量、血清NO及肺组织丙二醛 (MDA)含量 ,于LPS滴注后 6h动脉取血行血气分析。检测肺组织中iNOS和eNOS的表达。结果　LPS组与NS组比较 ,其生物学标志均显著升高 ;氧分压和HCO-3 明显降低 (P <0 0 1) ;iNOS表达显著增强 ,eNOS表达明显降低 (均P <0 0 1)。与LPS组比较 ,RPR1组和RPR2 组生物学标志显著降低 ;氧分压和HCO-3 明显升高 (P <0 0 5或P <0 0 1) ,iNOS表达明显降低 ,而eNOS表达明显升高 (均P <0 0 5 )。与LPS组比较 ,AG组仅iNOS表达明显降低。病理学检查显示 ,RPR1组和RPR2组肺组织损伤程度较LPS组明显减轻。结论　肺组织iNOS表达增强和eNOS表达降低是内毒素性ALI的重要机制 ,赤芍对内毒素性ALI的防治作用可能与抑制肺组织iNOS异常高表达和增加eNOS表达有关。

Protective effects of radix paeoniae rubra on lipopolysaccharide - induced acute lung injury and its mechanisms

Objective To investigate the effects and mechanisms of radix paeoniae rubra on lipopolysaccharide-induced acute lung injury.Methods Forty Wistar rats were divided randomly into 4 group:saline control(NS group),lipopolysaccharide group(LPS group),RPR for treatment group,RPR for prevention group and AG group.Histopathological examination were performed and biological indexes were measured for the lung specimens.Models of endotoxin induced ALI were used to observe the indexes including lung wet/dry weight,protein content and the ratio of neutrophiles in bronchoalveolar lavage fluid(BALF) and the activities of serum NO and MDA content in lung.Arterial blood was drawn for blood gas analysis.Expression of iNOS and eNOS in rat lung tissue was detected by immunohistochemistry and morphometry computer image analysis.The histological change of lung were observed under light microscope.Results Compared with NS group,the W/D,protein contents and the ratio of neutrophiles in BALF,the activities of serum NO,the content of MDA of group LPS were significantly increased(P<0.01),there was a significant decrease in the level of arterial bicarbonate and partial pressure of oxygen in the LPS group(P<0.01),expression of iNOS was markedly increased while expression of eNOS was significantly decreased in LPS group(P<0.01);But in RPR for treatment group and RPR for prevention group,these indexes of lung injury were significantly lower than in the group with LPS(P<0.01 or 0.05),expression of iNOS was significantly lower than that in LPS group and expression of eNOS was obviously higher than that in LPS group(P<0.05).Under light microscope,the pathological changes induced by LPS were significantly attenuated by RPR and AG.Conclusion The high-expression of iNOS and the low-expression of eNOS play important roles in lipopolysaccharide-induced acute lung injury.Protective effect of RPR on lipopolysaccharide-induced acute lung injury is related to the inhibition of iNOS expression and the increase of eNOS expression.