大剂量糖皮质激素治疗肺挫伤的实验研究

EXPERIMENATAL STUDY ON THE TREATMENT OF PULMONARY CONTUSION BY HIGH DOSE GLUCOCORTICOID

采用放射配基结合分析法，观察大鼠肺挫伤模型肺组织糖皮质激素受体（ＧＲ）的变化，并检测与其变化相关的皮质醇（ＧＣ）含量和磷脂酶Ａ＿２（ＰＬＡ＿２）的活性。结果发现，致伤后肺组织ＧＲ含量进行性降低，后期亲和力下降，同时ＰＬＡ＿２活性明显升高，两者呈显著负相关（Ｐ＜０．０１）。当静脉注射大剂量地塞米松（Ｄｅｘ）时，ＰＬＡ＿２活性明显受到抑制（Ｐ＜０．０１），同时肺水肿程度明显减轻（Ｐ＜０．０１）。肌肉注射ＧＲ阻断剂Ｒｕ＿（４８６）后，大剂量Ｄｅｘ的治疗作用被阻断。从而说明：肺挫伤后有继发性ＧＲ异常，由此所致的受体水平的ＧＣ功能不全，对肺挫伤的病理生理发展起到重要作用。

By radioligand binding assay,this experiment intended to investigate the changes of glucocorticoid receptor(GR) in pulmonary contusion of rats,and to determine the glucocorticoid(GC) level and phospholipase A 2(PLA 2) activity which is related to GR change.The results showed that the ammount of GR in pulmonary tissue after contusion decreased processively,and the affinity of GR also decreased later,whereas the activity of PLA 2 obviously increased simultaneously.There was an obvious negative linear relationship between them( r =-0 84, P <0 01).When high dose dexamethasone(Dex)was injected intravenously ,the activity of PLA 2 was depressed markedly ( P <0 01),meanwhile,the degree of pulmonary edema decreased noticeably.After muscle injection of Ru 486 ,the treatment effect of high dose Dex was reversed.The insufficiency of GC receptor caused by abnormal GR secondary to pulmonary contusion of rats was important in the course of pathophysiological progress of pulmonary contusion.