大鼠肺磷脂酶A_2激活与肺中肾上腺素能受体平衡失调

本研究动态地检测了油酸所致大鼠肺αAR与βAR平衡失调发生发展过程中肺PLA_2活性的变化,结果发现:实验组大鼠肺组织中PLA_2活性显著高于对照组,并且分别与αAR增多和βAR减少呈正相关和负相关,应用PLA_2非特异性抑制剂—氯喹预先处理实验组大鼠,可防止αAR和βAR的平衡失调,维持两种受体的数量与亲和力于正常水平,明显地减轻αAR与βAR失衡所致的肺部病变,肺体系数明显减小,支气管肺泡灌洗液中蛋白质含量亦显著低于实验组。

Activation of phospholipase A_2 and imbalance of adrenoceptors in the lung of rats

We have reported previously that the imbalance of adrenoceptors in the rat lung induced by oleic acid playing an important role in the pathoge nesis of permeability pulmonary edema. In order to explore its mechanism, the change of the activity of phospholipase A2 (PLA2) of the rat lungs was investigated and compared with the changes of a and β adrenoceptors (αAR, βAR). The results showed that the activity of PLA2 was increased significantly and shared respectively positive and negative correlation with the increase of αAR and the decrease of βAR. When the animals were pretreated with chloroquine, one of the nonspecific inhibitors of PLA2, the imbalance of αAR and βAR could be prevented; the maximal binding capacities of both types of adrenergicreceptors were maintained at their normal levels and the pathologic changes of the lungs caused by the imbalance of αAR and βAR were improved. Both lung coefficient and the concentration of protein in the broncho-alveolar lavage fluid were decreased significantly compared with that of the rats suffering from oleic acid injury. The results described above indicate that the activation of PLA2 in rat lungs may be an important cause of the imbalance of both types of adrenoceptors in the lung of the rats induced by oleic acid.