哮喘豚鼠磷脂酶A_2的变化及其抑制剂的作用

Changes of phospholipase A 2 activity and effects of its inhibitors in asthmatic guinea pigs

目的：探讨磷脂酶Ａ２（ＰＬＡ２）在哮喘和气道高反应发生中的作用及机理。方法：采用卵蛋白致敏豚鼠哮喘模型，观察支气管肺泡灌洗液（ＢＡＬＦ）中ＰＬＡ２活性变化及与气管平滑肌条最大收缩反应性（Ｅ－ｍａｘ）的关系，以及ＢＡＬＦ中细胞数、ＬＰＯ、蛋白质含量的变化及ＰＬＡ２抑制剂的防治作用。结果：哮喘组ＢＡＬＦ中ＰＬＡ２活性及Ｅｍａｘ显著增高，ＢＡＬＦ中细胞计数及ＬＰＯ、蛋白质含量也显著升高；ＢＡＬＦ中ＰＬＡ２活性与Ｅｍａｘ显著相关，也与细胞总数和ＬＰＯ含量显著相关。氯喹及地塞米松防治组Ｅｍａｘ及ＢＡＬＦ中ＰＬＡ２活性、细胞计数和ＬＰＯ含量显著降低。

Objective: To explore the role of phospholipase A 2 (PLA 2) in the occurrence of asthma and airway hyperresponsiveness and its mechanism. Methods: After the asthmatic model was established with ovalbumin aerosol in guinea pigs, the changes of PLA 2 activity in bronchoalveolar lavage fluid (BALF) and their relation with the responsiveness of strips of tracheal smooth muscle (Emax) were observed. Meanwhile, the changes of cell count and contents of lipid peroxide (LPO) and protein in BALF and the effects of PLA 2 inhibitors on asthma were also observed. Results: In asthma group, the PLA 2 activity, Emax, cell count and contents of LPO and protein were significantly increased (P<0.05) and the first index was remarkably correlated with the others (r=0.517, P<0.05). In chloroquine pretreated and dexamethasone pretreated groups, all the five indices were significantly decreased. Conclusion: PLA 2 play an important role in the infiltration of inflammatory cells into airway and occurrence of airway hyperresponsiveness in the asthmatic guinea pigs.