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 (Pa O2 )和血清肺表面活性物质蛋白 A(SP A)浓度 ,测定支气管肺泡灌洗液 (BAL F)中总磷脂 (TPL)、饱和磷脂酰胆碱 (DSPC)、总蛋白 (TP)、SP A、最小表面张力 (STmin)和肺组织中SP A m RNA含量及肺湿、干重量比值 (W/D)。结果 :与 NS组相比 ,OA组各时间点 BAL F中 DSPC/TPL、DSPC/TP和 ST A显著减少 (P <0 .0 5或 P<0 .0 1) ,而 TP、STmin和 W/D显著增加 (P <0 .0 5或 P <0 .0 1) ,且上述改变随观察时间的延长呈加剧趋势 ;OA组血清中 SP A在第 1小时即明显升高 ,并一直维持在较高水平 (P均 <0 .0 1) ;肺组织中 SP A m RNA含量在第 2、4小时显著减少 (P<0 .0 5 ) ;观察过程中 OA组TRC、FRC、Pa O2 与 STmin有显著负相关性 (P<0 .0 5或 P<0 .0 0 1) ,W/D与 STm in呈正相关 (P<0 .0 5 ) ,而STm in升高与 BAL F中 DSPC/TPL、SP A呈负相关 (P<0 .0 5或 P<0 .0 0 1) , Objective: To investigate the mechanism of pulmonary surfactant (PS) system changes in acute oleic acid (OA) -induced lung injury. Methods: Thirty-six New Zealand white rabbits were anesthetized and mechanically ventilated after tracheotomy. The animals were randomly divided into 2 groups (18 in each group), namely, oleic acid induced acute lung injury group (OA group) and saline control group (NS group). The animals were observed for 1, 2 and 4 hours (6 animals at each time point), monitoring of total TRC, FRC, PaO 2 and serum lung surface (TSP), total phosphatidylcholine (DSPC), total protein (TP), SP A, minimum surface tension (STmin) in bronchoalveolar lavage fluid (BALF) ) And lung tissue SP A m RNA content and lung wet and dry weight ratio (W / D). Results: Compared with NS group, the numbers of DSPC / TPL, DSPC / TP and ST A in BALF were significantly decreased in OA group at each time point (P <0.05 or P <0.01), but TP, STmin and W / D increased significantly (P <0.05 or P <0.01), and these changes tended to aggravate with the prolongation of observation time. In the serum of OA group, SP A increased significantly at the first hour and maintained The levels of SP A m RNA in lung tissue were significantly decreased at the second and fourth hour (P <0.05) at higher levels (all P <0.01). During the observation period, the levels of TRC, FRC, Pa O2 (P <0.05 or P <0.01). There was a positive correlation between W / D and STm in (P <0.05), while STm in was positively correlated with BALF DSPC / TPL, SP A was negatively correlated (P <0.05 or P <0.001)