急性肺损伤大鼠肺表面活性物质及肺表面活性物质蛋白的研究

Study of pulmonary surfactant and surfactant protein in rats with LPS-induced acute lung injury

目的 :探讨肺表面活性物质 (PS)及肺表面活性物质蛋白 (SP)在内毒素 (LPS)性急性肺损伤 (ALI)中的变化趋势。方法 :成年Wistar大鼠随机分为对照组 (NS组 )和肺损伤组 (ALI组 ) ,ALI组采用LPS诱导建立ALI模型。用定磷法和高效液相色谱法动态监测了NS组和ALI组第 1、3、5、7h大鼠支气管肺泡灌洗液 (BALF)中的总磷脂 (TPL)和磷脂各组分 ,采用逆转录聚合酶链反应 (RT -PCR)的方法检测肺组织SP -A、SP -BmRNA的表达情况 ,此外对肺损伤的病理学改变也进行了对比分析。结果 :与NS组比较 ,ALI组有明显水肿、出血和炎症。BALF中TPL在 1、3、5、7h明显低于NS组 (P <0 .0 5 ) ,卵磷酯胆碱 (PC)在 3、5、7h明显低于NS组 (P <0 .0 5 ) ;而溶血卵磷脂 (LPC)在 1、3、5、7h明显高NS组 (P <0 .0 5 )。肺组织SP -A、SP -BmRNA表达在 3、5、7h明显低于NS组 (P <0 .0 5 )。结论 :ALI存在PS的代谢改变 ,以及SP -A、SP -BmRNA的表达降低 ,PS含量的降低和组分的改变是导致难以纠正的低氧血症重要原因之一。

Objective:To study the alteration trend of pulmonary surfactant(PS) and surfactant-associated protein(SP) in rats with LPS-induced acute lung injury(ALI).Methods:Fifty-six adult Wistar rats were randomly divided into normal saline(NS) group and ALI group.The levels of mRNA of the SP-A,SP-B were measured by reverse transcription polymerase chain reaction(RT-PCR) during iv LPS at 1,3,5,7h.The content and component of PS in the bronchoalveolar lavage fluid (BALF) were measured by high performance liquid chromatography (HPLC).In addition,studies on lung dry/wet weight ratio,the protein content of BALF,alveolar oxygen partial pressure (PaO 2)and histological changes were performed.Results:Compared with the NS group,ALI group developed severe lung damage.Edema,hemorrharge and inflammatory changes were found.Total phospholipids (TPL) of BALF at 1,3,5,7h were lower than those in the NS group( P <0.05);phosphatidylcholine(PC) at 3,5,7h were lower than those in the NS group( P <0.05);while lysophosphatidylcholine (LPC) at 1,3,5 ,7h were higher than thosein the NS group(P <0 .0 5 ) .Theexpression ofSP -A ,SP -Bm RNAat 3,5 ,7h were less than thosein the NSgroup(P <0 .0 5 ) .Conclusion :The changed metabolism of PSex ists in the pathogenesisn of ALI,which is mainly de monstratedas that the decreasein TPL ,PC ,will de crease expression of SP -A ,SP -Bm RNA .Decreasein content and changein components of PS may play an important role in severe hypoxemia in ALI .