大鼠烟雾吸入伤后肺表面活性物质磷脂组分含量的变化及意义

为探讨烟雾吸入后肺表面活性物质(PS)磷脂组分含量的变化和可能机理及其与 PS 活性抑制和肺功能损害的关系,采用大鼠烟雾吸入伤模型,分别检测了正常对照及致伤2,6,12和24小时大鼠静态肺顺应性(Cst)、支气管肺泡灌洗液(PALF)表面张力活性、BALF 和肺匀浆总磷脂(TPL)、磷脂酰胆碱(PC)、磷脂酰肌醇(PI)、磷脂酰丝氨酸(Phs)、磷脂酰乙醇(PE)含量、BALF 和肺匀浆中磷脂酶 A_2(PLA_2)活性。结果表明动物伤后 Cst 显著降低;BALF 最小表面张力(STmin)进行性升高;BALF 中TPL 增加,但 PC(%TPL)明显降低,且与 Cst 和 STmin 的变化相关显著;肺组织内 TPL 及 PC 均下降,并与其中 PLA_2活性升高明显相关。结论:烟雾吸入伤早期肺内 PS 磷脂组分含量明显改变,PC 相对含量减少是引起 PS 活性抑制及肺功能障碍的主要原因之一,PLA_2可能在 PS 组分异常和(或)含量减少中起重要作用。

Changes and significance of phospholipid composition contents of pulmonary surfactant after smoke in- halation injury in rats

Objective:To evaluate the changes and possible mechanisms of phospholipid composition contents of pulmonary surfactant(PS),and to investigate the relationship between these changes and the PS activity inhibition,as well as pulmonary dysfunction after smoke inhalation.Methods:Following the induction of smoke inhalation injury in rats,static lung compliance(Cst),surface tension properties of bronchoalveolar lavage fluid(BALF),the contents of total phospholipids,phosphatidylcholine(PC), phosphatidylinositol(PI),phosphatidylserine(Phs),phosphatidylethanolamine(PE),and the activities of phospholipase A_2 in BALF and lung tissues were determined respectively in normal control and in- jured animals at 2,6,12 and 24 h after injury.Results:After smoke inhalation,the static lung compliance decreased markedly.The minimum surface tension(STmin)of BALF increased progressively.The TPL level in BALF increased,while the PC relative content(% TPL)reduced dramatically with pronounced correlation between its change and the changes of Cst,as well as STmin.Both TPL and PC contents in lung tissues decreased,while their changes correlated significants with the increase of phospholipase A_2 activity.Conclusion:The change in phospholipid composition contents of PS in lungs occur at the early stage after smoke inhalation.The decrease of PC relative content is one of the main causes to induce PS activity inhibition and pulmonary dysfunction.PLA_2 may play an important role in introducing abnormal- ity of PS composition and/or decrease of PS content.