含葡聚糖肺表面活性物质对脂多糖诱发的急性肺损伤大鼠肺功能的影响

Effects of a dextran-containing pulmonary surfactant on pulmonary function in rats with acute lung injury induced by lipopolysaccharide

目的验证葡聚糖在机体内能否增强肺表面活性物质(PS)对急性肺损伤的疗效。方法大鼠20只,经气管注入脂多糖(LPS)制成肺损伤模型后,随机分为二组:肺表面活性物质组(PS组),气管内注入PS(6mg/mL)2mL/kg;含葡聚糖肺表面活性物质组(DPS组),经气管注入含1%葡聚糖的PS(6mg/mL)2mL/kg。观察期间行定压式人工通气。结果治疗前PS组和DPS组PaO2无明显差异[(86.4±10.9)mmHg比(75.1±14.7)mmHg,P>0.05]。行替代疗法后两组大鼠的PaO2均显著增加,其中DPS组的PaO2增加值大于PS组(P<0.05)。治疗前两组大鼠PaCO2无明显差异[(39.4±8.4)mmHg比(48.1±11.0)mmHg,P>0.05],行替代疗法后两组大鼠的PaCO2均有所下降,但PS组的下降幅度较小,并且在60min时有回升。DPS组的PaCO2下降幅度大于PS组(P<0.01)。替代疗法后两组大鼠的胸肺顺应性有所改善,但组间差异无统计学意义。结论葡聚糖可增强PS替代疗法对急性肺损伤大鼠的疗效。

Objective To verify whether dextran can improve the efficacy of pulmonary surfactant （PS） on pulmonary function in rats with acute lung injury. Methods Twenty rats were anesthetized with ip injection of pentobarbital sodium and ventilated at 25 cm H2O peak inspiratory pressure and 7.5 cm H2O positive end-expiratory pressure with pure oxygen. The experimental acute lung injuries of all rats were induced by injection of lipopolysaccharide （PS） into the lungs. Then the rats were divided into two groups randondy, ie, pulmonary surfactant group （PS group, n = 10） ： receiving intratracheal instillation of PS （6 mg/mL, 2 mL/kg） ; and dextran plus PS group （ DPS group, n = 10） ： receiving intratracheal instillation of the same dose of PS containing 1% dextran. Results Before PS instillation, the values of PaO2 had no significant difference between two groups [ （86.4 ±10.9） mmHg vs （75.1 ±14.7） mmHg, P 〉 0.05 ]. The PaO2 of both groups were significantly increased after PS instillation, and the change of PaO2 in the DPS group was significantly greater than that in the PS group. Before PS instillation, the values of PaCO2 had no significant difference between two groups [（39.4±8.4） mm Hg vs （48.1 ± 11.0） mm Hg, P〉0.05]. After PS instillation, the PaCO2 in the DPS group was decreased significantly. Whereas, the decrease of PaCO2 in the PS group was small and the PaCO2 rose again at 60 minutes after PS instillation. The decrease of PaCO2 in the DPS group was greater than that in the PS group （ P 〈 0.05 ）. The thoracic and lung compliance improved after PS and DPS replacement,however,no significant difference was found. Conclusion Dextran can reinforce the efficacy of pulmonary surfactant replacement in acute lung injury rats.