【作者】 刘燕；

【导师】 袁雅冬；

【作者基本信息】 河北医科大学 ， 内科学， 2010， 硕士

【摘要】 目的:肺栓塞(pulmonary embolism,PE)时,肺血管阻力上升除了机械性因素之外,神经、体液因素和循环内分泌激素也起了十分重要的作用。肺栓塞发生后,肺血管内皮受损,释放出大量血管活性物质,如内皮素、血管紧张素Ⅱ、尾加压素Ⅱ等,使肺血管收缩,影响肺循环。Apelin是新发现的小分子活性多肽,为孤儿G蛋白偶联受体-血管紧张素AT-1相关蛋白(APJ)的天然配体。在中枢与众多外周的组织器官都已发现有Apelin和APJmRNA及蛋白的表达,其中,肺脏中表达的水平最高。研究表明,Apelin-APJ系统具有调节循环稳态、抗炎与抗病毒、调节免疫、促内皮增殖及抗氧化损伤等功能。虽然目前Apelin-APJ系统在肺循环调节中的意义还未完全明了,但已有充分的证据提示:Apelin是一种多靶点、作用广泛的新的内源性保护因子,Apelin-APJ系统对于生理状态下肺循环稳态的维持及相关肺部疾病的发生发展可能有着特殊的作用。本实验通过建立APE模型,检测Apelin和APJ及AngII血浆及肺组织匀浆中的变化以及与肺动脉高压形成的关系,探讨三者对血流动力学的影响和APE后肺动脉高压形成的作用。方法:健康新西兰大白兔64只,体重2.5～3.5kg,雌雄不拘,采用Berman球囊漂浮导管置入兔左下肺动脉开口处,充盈球囊,建立兔APE动物模型。随机分为8组:(1)对照组(n=8),(2)假手术组(n=8),(3)栓塞1h组(n=8),(4)栓塞2h组(n=8),(5)栓塞4h组(n=8),(6)栓塞8h组(n=8),(7)栓塞12h组(n=8),(8)栓塞24h组(n=8)。各组动物分别于栓塞前、栓塞即刻、栓塞1h、栓塞2h、栓塞4h、栓塞8h、栓塞12h、栓塞24h等时间点监测肺动脉平均压(pulmonary arterial mean pressure,PAMP)。于实验终点放血处死动物。采用酶联免疫吸附法(ELISA)测定血浆及肺组织匀浆中Apelin和APJ,用放免法测定血浆及肺组织匀浆中AngⅡ的含量。结果:1栓塞前后肺血流动力学的变化:栓塞即刻PAMP急剧升高,明显高于栓塞前和假手术组水平(P均<0.05);栓塞0.5h开始下降,1h继续下降,但仍明显高于栓塞前水平(P均<0.05);栓塞2h、4h、8h下降至栓塞前水平和假手术组水平(P均>0.05);栓塞12h、24h时,PAMP再次升高,并且明显高于栓塞前和假手术组水平(P均<0.05)。2血浆及肺组织匀浆中Apelin的变化:各组之间血浆及肺组织匀浆中Apelin的变化趋势基本相同;对照组与假手术组Apelin的浓度无明显差异(P>0.05);栓塞1h、栓塞2h、栓塞4h、栓塞8h各组Apelin的浓度均高于对照组水平(P均<0.05);于栓塞2h时Apelin的浓度达到最高峰;至栓塞12h和栓塞24h Apelin浓度又下降至低于对照组水平(P均<0.05)。3血浆及肺组织匀浆中APJ的变化:各组之间血浆及肺组织匀浆中APJ的变化趋势基本相同;对照组与假手术组APJ的浓度无明显差异(P>0.05);栓塞1h、栓塞2h、栓塞4h、栓塞8h各组APJ的浓度均对照组水平(P均<0.05);栓塞2h组APJ的浓度达到最高峰;至栓塞12h和栓塞24h APJ浓度又下降至低于对照组水平(P均<0.05)。4血浆及肺组织匀浆中AngⅡ的变化:各组之间血浆及肺组织匀浆中AngⅡ的变化趋势基本相同;对照组、假手术组AngⅡ的浓度无明显差异(P>0.05);栓塞lh组、栓塞2h组、栓塞4h组和栓塞8h组AngⅡ的浓度明显高于对照组水平(P均<0.05);栓塞12h组与栓塞24h组时间点AngⅡ的浓度均明显高于其他各组水平(P均<0.05);栓塞24h组AngⅡ的浓度又高于栓塞12h组水平(P<0.05)。但是,血浆中AngⅡ浓度较对照组升高的倍数明显高于肺组织匀浆中AngⅡ浓度较对照组升高的倍数。5血浆中AngⅡ、Apelin比值的变化:对照组、假手术组、栓塞1h、2h和栓塞4h组AngⅡ、Apelin比值无明显差异(P均>0.05);栓塞8h组AngⅡ/Apelin比值略高于对照组,但亦无统计学意义(P>0.05);栓塞12h、栓塞24h组AngⅡ、Apelin比值明显升高,高于其他各组水平(P均<0.05)。6相关分析:统计分析显示栓塞2h、4h、8h、12h、24h各组血浆中Apelin、AngⅡ呈负相关关系(r=﹣0.81 P <0.05),AngⅡ、Apelin比值与肺动脉平均压之间呈正相关关系(r=0.703 P<0.05)。结论:1肺循环阻力升高、急性肺动脉高压等血流动力学改变共同形成APE损伤的基础。2 Apelin-APJ系统和AngⅡ参与了APE的肺血管反应,它们与APE后肺血流动力学的变化,肺动脉高压的形成过程有一定的联系。3 Apelin参加的肺血管反应机制可能与拮抗AngⅡ有关。4 Apelin及其受体APJ尚可作为反映APE肺动脉压力变化的一个新指标。更多还原

【Abstract】 Objective: The pulmonary embolism is a clinic syndrome caused by endogenous or exogenous embolus obstructs pulmonary artery. Increasing of pulmonary vascular resistance and pulmonary artery pressure is pathophysiological foundation of APE.Embolic effection of“mechanical obstruction”is immediate cause of increasing of pulmonary vascular resistance. In addition, Neurohumor has also possessed important effection on change of pulmonary circulation in embolism earlier period. Lung vascular endothelium damaging after lung embolism releases of lots of vasoactive substances, such as endothelin , AngⅡand UrotensinⅡ.Apelin was found in 1998 to be congaed endogenous ligand for the APJ receptor (a putative receptor protein related to the angiotensin-type 1 receptor), which had been previously designated an“orphan”G-protein-coupled coupled receptor (GPCRs) and firstly identified by the Human Genome Project. The structure of Apelin and APJ is highly conserved among species, suggesting its importantly physiological roles. It is well known that GPCRs represents the greatest proportion of known therapeutic targets.Study shows Apelin might play a role in regulating fluid homeostasis and immune fuction,inhibiting that human immunodeficiency circus infection by blocking the virus co receptor.So far, however, there is little information of the functional roles of Apelin and APJ in pulmonary circulation, but there is sufficient evidence to show that it plays an important role of multi-targets, a wide range of new endogenous protective factor. Apelin-APJ system may have a special role of the maintenance of steady-state of pulmonary circulation and related to the development of lung diseases. Purpose of the experiment is to investigate their effects and the possible mechanisms of pulmonary artery hypertension following APE. Method:sixty-four New Zealand rabbits, weighing 2.5～3.5kg,the male and female were given consideration to, were obstructed the left lower lung artery by inflating gas of 5F Berman sacculus catheter to set up rabbit APE model.The animals were randomly divided into eight groups:(1) control group(n=8), (2)sham operation group(n=8), (3)embolism 1h group(n=8), (4)embolism 2h group(n=8), (5)embolism 4h group(n=8), (6)embolism 8h group(n=8) (7)embolism 12h group(n=8) (8)embolism 24h group(n=8). We monitored the pulmonary arterial mean pressure (PAMP) at pre-embolization, embolization instantly, embolization1h, 2h, 4h, 8h, 12h and 24h. We detected the content of Apelin and APJ in plasma by ELISA method, and the content of AngⅡby Radioimmunoassay method at embolization1h, 2h, 4h, 8h, 12h and 24h. We monitored the relationship between the three and pulmonary artey hypertension.Results:1.The changes of lung hemodynamics before and after embolism:PAMP was rapidly increased after embolis, and was obvously higher than pre-embolization and sham group lever (P<0.05, respectively). PAMP was decreased gradually at embolization 0.5h,1h,but still higher significantly than pre-embolization(P<0.05,respectively). PAMP was decreased to the pre-emblization and sham group level at embolism 2h 4h and 8h. PAMP was increased again at embolism 12h and 24h, and was higher than pre-embolization and sham group lever (P<0.05, respectively)2.The change of Apelin in plasma and lung homogenate: Between the groups in plasma and lung homogenate in Apelin trends in basically the same; The content of plasma Apelin were higher significantly at embolization 1h, 2h, 4h, 8h than control group and the sham operation group(P<0.05 ,respectively).At the embolization 2h group, the content of plasma Apelin achieved peak. The content of plasma Apelin gradually decreased at embolismation 8h, 12h and 24h. The content of plasma Apelin at the embolization 12h and 24h group are significant lower than the control group. (P﹤0.05, respectively).3.The change of APJ in plasma and lung homogenate: Between the groups in plasma and lung homogenate in APJ trends in basically the same ;The content of plasma APJ were higher significantly at embolization 1h, 2h, 4h, 8h than control group and the sham operation group(P<0.05,respectively).At the embolization 2h group, the content of plasma APJ achieved peak. The content of plasma APJ gradually decreased at embolismation 8h, 12h and 24h. The content of plasma APJ at the embolization 12h and 24h group are significant lower than the control group. (P﹤0.05, respectively).4.The changes of AngⅡin plasma and lung homogenate: Between the groups in plasma and lung homogenate in AngⅡtrends in basically the same;the content of plasma AngⅡwere higher significantly at embolization lh, 2h, 4h, 8h, 12h and 24h than the control group.(P<0.05,respectively), the content of plasma AngⅡwere higher at embolization 12h and 24h than embolization 1h, 2h, 4h and 8h. (P<0.05,respectively)and gradually increased accompanied the prolongation of embolization.However, the plasma concentration of AngⅡmultiples higher than the control group was significantly higher than in lung homogenate concentration of AngⅡmultiples higher than the control group.5.The relation between AngⅡ/Apelin ratio and pulmonary artery hypertension: the ratio were not significant difference at control group, sham group and embolization 1h,2h, 4h, 8h (P>0.05, respectively). The ratio at embolization 12h and 24h were higher than the control group and sham group lever (P<0.05, respectively).6.The coefficient correlation was analyzed: Statistic analysis showed that the content of plasma AngⅡand Apelin were negative correlation(r=﹣0.81 P <0.05); the content of plasma AngⅡ/Apelin ratio and PAMP were correlated significantly positively (r=0.703 P<0.05). Conclusion:1.Elevated pulmonary vascular resistance, acute pulmonary hypertension and other hemodynamic changes together form the foundation of APE injury.2.Increased pulmonary vascular resistance, acute pulmonary hypertension and so on, form the base of hemodynamic derangements, which may lead to pulmonary injury in APE.3.The mechanism of Apelin to participate pulmonary vascular response may be related to the antagonist of AngⅡ.4.Apelin as a original factor can reflect the pulmonary artery pressureof APE.更多还原