肺表面活性物质在急性油酸性肺损伤时的变化

目的：探讨肺表面活性物质（ＰＳ）系统在急性油酸（ＯＡ）性肺损伤时变化的作用机制。方法：３６只新西兰白兔经麻醉、气管切开插管后给予机械通气。动物随机分成２组（每组１８只），即油酸致急性肺损伤组（ＯＡ组）和生理盐水对照组（ＮＳ组）。观察１、２和４小时（各时间点动物均为６只），监测静态胸肺总顺应性（ＴＲＣ）、肺功能残气量（ＦＲＣ）、动脉血氧分压（ＰａＯ２）和血清肺表面活性物质蛋白Ａ（ＳＰ－Ａ）浓度，测定

Changes in pulmonary surfactant after acute lung injury induced by oleic acid

Objective:To investigate the changes in pulmonary surfactant after acute lung injury (ALI) induced by oleic acid.Methods:Thirtysix adult rabbits were anaesthetized,received tracheostomy tube insertion and then mechanically ventilated.The animals were randomly divided into two groups which were acute lung injury induced by oleic acid inhalation (OA group,n=18) and normal control treated by saline inhalation (NS group,n=18).Total static compliance of respiratory system (TRC),functional residual capacity (FRC),PaO 2 and the serum surfactant protein A level were monitored and assayed at 1,2 and 4 hours after operation.The level of SPA and SPA mRNA expression were determined using Western blot analysis and Northern blot method.After the animals were sacrificed,the tissue content of total phospholipid (TPL),desaturated phosphatidylcholine (DSPC),total proteins (TP) in lungs were analyzed.Results:DSPC/TPL, DSPC/TP and SPA in the BALF were significantly and progressively decreased (P<0 05 or P<0 01) from 1 hour after oleic acid inhalation whereas TP,STmin and serum SPA concentration were progressively increased (P<0 05 or P<0 01).SPA mRNA expression showed no change at 1 hour and significant decrease at 2 and 4 hours as compared with control (P0 05).The values of TRC,FRC and PaO 2 were negatively correlated to STmin (P<0 05 or P<0 001) in OA group.STmin was,in turn,negatively correlated to DSPC/TPL( P<0 05 ) and SPA(P<0 001) and positively correlated to TP in BALF(P<0 005).Conclusions:The increase of STmin of bronchoalveolar lavage fluid(BALF) was closely associated with the decrease of DSPC/TPL and SPA and the increase of TP in lungs.This indicates the etiological role of PS inactivation in the impairment of respiratory function in acute lung injury induced by oleic acid inhalation.