肝肺综合征大鼠肾上腺髓质素及其受体的表达

Expressions of adrenomedullin and its receptor in the rats of hepatopulmonary syndrome

目的 探讨肾上腺髓质素 (ADM)在肝肺综合征 (HPS)发病机制中的作用。方法 采用Wistar大鼠行胆总管结扎术 (CBDL)制备HPS动物模型 ,进行血气分析 ,使用放射免疫方法检测血浆和肺组织匀浆中ADM水平 ;采用RT PCR方法检测肺组织中ADMmRNA及其特异性受体L1mRNA的表达。结果 (1)从术后第 3周至第 5周 ,CBDL组大鼠血浆和肺组织中ADM水平动态升高 ;(2 )CBDL 5周组大鼠肺组织中ADMmRNA的表达较对照组升高 ,差异有显著性 (P <0 .0 5 ) ,而两组间L1mRNA的表达差异无显著性 (P >0 .0 5 ) ;(3)相关分析表明 ,各阶段血浆和肺组织ADM水平均与天冬氨酸转氨酶 (AST)、门静脉压力、肺泡 动脉氧分压差 (A aDO2 )呈正相关 ,出现腹水者血浆和肺组织ADM水平高于未出现腹水者。结论 在HPS形成过程中 ,血浆和肺组织中扩血管物质ADM水平持续升高 ,与肝功能受损状态、门脉压力升高程度、腹水形成及PaO2 降低有关 ,提示ADM增多可能参与HPS时肺内血管扩张 (IPVD)的发生。

Objective To investigate the role of adrenomedullin (ADM) in the pathogenesis of hepa-topulmonary sydrome(HPS). Methods Common bile duct ligation(CBDL) was performed in Wistar rats at the third week, fourth week and fifth week after the operation. The rats were sacrificed to evaluate arterial blood gases. The blood and lung tissue samples were collected to assess the concentration of ADM by radioimmunoassay. RT-PCR was performed to detect levels of ADM mRNA and its special receptor L1 mRNA in lung. Results (1) The levels of plasma and lung ADM were gradually increased from the third week to fifth week after CBDL. (2) The level of ADM mRNA in the lung of CBDL 5 week group was increased. There was a significant difference in the expression of L1 mRNA between control and CBDL 5 week group(P< 0.05),while no notable difference was seen between the two groups(P> 0.05). (3) Plasma and lung ADM were positively correlated with AST, pressure of portal vein and A-aDO 2. The levels of ADM in blood and lung of rats with ascites were higher than that without ascites. Conclusions The levels of ADM in plasma and lung were increased during the process of HPS, which was correlated with impaired liver function, increased pressure of portal vein, ascites and decreased PaO 2. Theses results suggest that ADM may contribute to the IPVD of HPS.