磷脂酶A_2在内毒素致中性粒细胞肺内聚集和损伤中的作用

The Role of Phospholipase A_2 in Endotoxin-induced Neutrophil Accumulation and Injury in Lung

为了研究磷脂酶A_2（PLA2）在内毒素致中性粒细胞肺内聚集和损伤中的作用，给SD大鼠静注大肠杆菌内与毒素后4h检测了肺组织和支气管肺泡灌洗液（BALF）中PLA2活性和中性粒细胞数量，并观察了PLA2抑制剂氯喹对上述检测结果的影响。结果显尔：①内毒素引起肺损伤和肺内中性粒细胞的增加；②内毒素注射后肺组织和BALF中PLA2活性均增高，氯喹可部分抑制该过程；③中性粒细胞在肺组织和BALF中聚集程度与肺损伤指标（肺系数、BALF中蛋白和丙二醇含量）之间呈显著正相关；④肺内PLA2活性与中性粒细胞数之间呈显著正相关。该结果提示，PLA2参与了内毒素引起的中性粒细胞在肺内聚集及肺损伤过程。

To investigate the effect in vivo of phospholipase A2 (PLA2) on neutrophils accumulation and sequestration, PLA2 activity in lung tissue and bronchial-alveolar lavage fluid (BALF) were assayed 4 hours after intravenous injection of E. coli endotoxin O111 B4 in SD rats and the neutrophils in the lung tissue and BALF were calculated simultaneously. Chloraquine, a PLA2 inhibitor, was pretreated to study the relation between PLA2 activity and quantitation of neutrophils. The results showed that ①the endotoxin elicited acute lung injury and infiltration of neutrophils into the lung;② PLA2 activities on both lung and BALF were enhanced in the endotoxin-induced lung injury, while Chloroquine could partly block the increase of PLA2 activities;③accumulation of neutrophils in lung tissue and BALF correlated positively with the indexes of lung injury (lung coefficient, protein and MDA concentration in BALF); ④PLA2 activity of lung tissue and BALF correlated positively with the accumulation of neutrophils respectively in lung tissue and BALF. It suggests that PLA2 participates in neutrophil accumulation and activation in the process of acute lung injury induced by endotoxin.