肺血管内皮功能紊乱与肺动脉高压

肺动脉高压是以肺血管阻力进行性增加并伴有不可逆的血管重塑为特征的疾病.越来越多的研究表明,肺血管内皮功能紊乱在肺动脉高压形成的起始及发展阶段都起着重要作用.本文就肺血管内皮功能紊乱在肺动脉高压发病机制中的研究进展作一综述.     

内皮祖细胞和肺动脉高压

肺动脉高压是以肺动脉压和肺血管阻力进行性增加及右心功能衰竭为特征,内皮功能障碍为主的恶性肺血管疾病.本文总结了近年来内皮祖细胞(EPC)动员、归巢分子生物学的研究进展.研究了血管内皮生长因子等生长因子和他汀类等药物对EPC动员,归巢治疗肺动脉高压的影响以及EPC、基因修饰后EPC移植对肺动脉高压治疗的影响.同时讨论了EPC治疗的潜在不良反应.EPC为肺动脉高压患者提供新的治疗方法.     

慢性阻塞性肺疾病相关性肺动脉高压研究进展

肺动脉高压是慢性阻塞性肺疾病的一个重要合并症.慢性阻塞性肺疾病相关的肺动脉高压多为轻到中度且进展缓慢,香烟烟雾、炎症产物引起内皮损害,造成内皮功能失调;慢性低氧引起肺血管收缩;肺血管重塑导致管腔变小;血管膨胀性降低,阻力增加;重度肺气肿时肺-毛细血管的丧失等均与慢性阻塞性肺疾病时的肺动脉高压相关.     

血管内皮功能障碍与肺动脉高压

肺动脉高压是以血管增殖重塑、原位血栓形成、肺血管床进行性闭塞、肺血管阻力进行性增高为特征的肺小动脉疾病。其发病机制是一个复杂的、多因素参与的过程。近来越来越多的研究表明,肺脏血管内皮功能障碍在肺动脉高压形成的起始及发展阶段都起着重要作用。正常的肺脏血管内皮衬于肺血管内腔表面,介于循环血和肺血管平滑肌之间。其不仅具有生理屏障功能,还有调解血管张力,血液流动性和黏附性,参与血管内皮损伤的修复,同时血管内皮可以通过膜受体感知血流动力学和血源性信号变化参与细胞间的信号传导[1]。肺脏内皮功能障碍是肺脏内皮细胞在…     

内皮祖细胞在肺动脉高压的作用

内皮祖细胞是成熟血管内皮细胞的前体细胞,属于干细胞群体,其在血管再生与修复方面的应用越来越受到关注.肺动脉高压作为一种致死性很高的肺血管疾病,其发病与血管内皮损伤密切相关.目前的研究证实,内皮祖细胞在肺动脉高压血管内皮修复中具有重要作用,内皮祖细胞移植有可能成为临床治疗肺动脉高压的一种有效手段.     

肺内皮功能障碍与肺动脉高压病变研究进展

肺动脉高压(PH)共同特征是内皮细胞异常增殖伴随血管生成,形成丛状病变,特点是肺动脉重构,始动因素为肺内皮功能障碍。内皮功能障碍指内皮源性收缩和舒张血管物质失衡所致的一种内皮病理状态,肺内皮功能障碍主要表现为肺内皮产生的相关活性因子和凝血异常,导致肺血管异常收缩、原位血栓和血管重构形成,导致PH的发生发展。本文就PH中肺内皮功能障碍表现、发生机制和相关药物治疗作一综述。     

血管内皮生长因子与肺部疾病的关系

血管内皮生长因子是作用于血管内皮细胞的重要血管调节因子,它通过与内皮上的特异受体结合,发挥促进内皮细胞增殖、分化、诱导血管生成、增加微血管通透性等多种功能。近年研究显示血管内皮生长因子在慢性阻塞性肺疾病、肺动脉高压、急性肺损伤、肺癌等疾病发病中起到了重要作用。本文就血管内皮生长因子在慢性阻塞性肺疾病、肺动脉高压、急性肺损伤、肺癌等疾病中的作用综述如下。     

慢性缺氧性肺动脉高压大鼠内皮依赖性舒缩因子的变化

慢性缺氧性肺动脉高压大鼠内皮依赖性舒缩因子的变化李志斌邹霞英容中生缺氧性肺血管收缩反应（ＨＰＶ）和肺血管结构重建是缺氧性肺动脉高压（ＰＨ）形成和发展的主要因素。缺氧致肺血管内皮细胞（ＥＣ）损伤［１］，影响ＥＣ分泌内皮依赖性舒缩因子的平衡，增强ＨＰＶ和...     

血管内皮生长因子与慢性阻塞性肺疾病继发肺动脉高压的关系

血管内皮生长因子(vascular endothelial growth factor,VEGF)是一种重要的血管内皮细胞丝裂原和通透因子.肺血管的重塑与慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)继发肺动脉高压密切相关.VEGF贯穿于COPD发展的全过程,在COPD的不同时期呈现不同的表达水平,发挥不同的生物学作用.气道炎症、低氧等因素可以在COPD早期促进VEGF及其受体的表达上调从而导致肺血管重塑的发生发展,VEGF也可以对COPD后期继发肺动脉高压时的重度肺血管重塑起到一定的修复作用.通过阐述VEGF、COPD肺血管重塑及继发肺动脉高压之间的相互关系,可以对COPD继发肺动脉高压的诊断和治疗提供新的思路.     

用伊洛前列素吸入治疗心脏病患者围术期肺动脉高压

目前肺动脉高压的治疗仍然是一个棘手的问题,前列环素类似物伊洛前列素是近年来应用较多的肺动脉高压治疗药物,由于其具有高度肺血管选择性、能调节肺血管内皮功能、抑制血管重塑和微血栓形成等药物学特点,因此可明显改善血流动力学和临床症状。本文主要综述吸入伊洛前列素在成人心脏手术围术期肺动脉高压的应用。     

内皮细胞凋亡与肺动脉高压

随着肺动脉高压研究的不断深入,肺血管内皮细胞凋亡在肺动脉高压形成过程中的重要作用被逐步认识。多种疾病和环境因素导致肺血管内皮损伤、内皮细胞凋亡增加、功能障碍,从而促进肺动脉平滑肌细胞和成纤维细胞增殖、肺动脉重构和血栓形成;肺血管内皮细胞凋亡还诱导产生凋亡抵抗表型的内皮细胞过度增殖,形成丛样病变和肺血管闭塞,最终导致严重肺动脉高压。因而在肺动脉高压发生发展的不同时期,调控肺血管内皮细胞凋亡可能是预防和治疗肺动脉高压的一种新策略。     

氧化应激和肺动脉高压血管重构

氧化应激可通过促进肺动脉血管平滑肌细胞增殖、加重血管内皮功能损伤和促进血管外基质增生等多条途径参与肺动脉血管重构,加速肺动脉高压的发生发展进程。近来研究发现,针对氧化应激进行的抗氧化治疗可有效地抑制肺动脉血管重构及肺动脉高压的发生,进一步证明了氧化应激在肺动脉血管重构乃至肺动脉高压中的重要作用。阐明病理条件下氧化还原信号途径,寻找抗氧化治疗的特异性药物,是肺动脉高压抗氧化治疗的基础和研究方向。     

Diabetes Mellitus Associates with Increased Right Ventricular Afterload and Remodeling in Pulmonary Arterial Hypertension

Background

Diabetes mellitus is associated with left ventricular hypertrophy and dysfunction. Parallel studies have also reported associations between diabetes mellitus and right ventricular dysfunction and reduced survival in patients with pulmonary arterial hypertension. However, the impact of diabetes mellitus on the pulmonary vasculature has not been well characterized. We hypothesized that diabetes mellitus and hyperglycemia could specifically influence right ventricular afterload and remodeling in patients with Group I pulmonary arterial hypertension, providing a link to their known susceptibility to right ventricular dysfunction.

慢性阻塞性肺疾病合并肺动脉高压的发病机制研究进展

肺动脉高压(pulmonary hypertension,PH)是慢性阻塞性肺疾病(chronic obstructivepulmonary disease,COPD)的一个重要合并症.COPD合并PH是逐渐发生和进展的,最初于运动或睡眠时出现,逐渐发展为休息时即存在PH,运动、睡眠或病情恶化时进一步升高.COPD相关的PH多为轻到中度,但某些COPD患者可表现为"不成比例"的PH.香烟烟雾、炎症产物引起内皮损害,造成内皮功能失调;慢性低氧引起肺血管收缩;肺血管重构导致管腔变小,血管膨胀性降低,阻力增加;重度肺气肿时肺毛细血管的丧失等均与COPD时的PH相关.     

Hematological disorders and pulmonary hypertension

Pulmonary hypertension(PH),a serious disorder with a high morbidity and mortality rate,is known to occur in a number of unrelated systemic diseases.Several hematological disorders such as sickle cell disease,thalassemia and myeloproliferative diseases develop PH which worsens the prognosis.Associated oxidant injury and vascular inflammation cause endothelial damage and dysfunction.Pulmonary vascular endothelial damage/dysfunction is an early event in PH resulting in the loss of vascular reactivity,activation of proliferative and antiapoptotic pathways leading to vascular remodeling,elevated pulmonary artery pressure,right ventricular hypertrophy and premature death.Hemolysis observed in hematological disorders leads to free hemoglobin which rapidly scavenges nitric oxide(NO),limiting its bioavailability,and leading to endothelial dysfunction.In addition,hemolysis releases arginase into the circulation which converts L-arginine to ornithine,thus bypassing NO production.Furthermore,treatments for hematological disorders such as immunosuppressive therapy,splenectomy,bone marrow transplantation,and radiation have been shown to contribute to the development of PH.Recent studies have shown deregulated iron homeostasis in patients with cardiopulmonary diseases including pulmonary arterial hypertension(PAH).Several studies have reported low iron levels in patients with idiopathic PAH,and iron deficiency is an important risk factor.This article reviews PH associated with hematological disorders and its mechanism:and iron homeostasis and its relevance to PH.     

Which prognostic factors should be used in PH in elderly patients?

In recent times, the prevalence of pulmonary arterial hypertension (PAH) is more commonly seen among elderly populations. The increased prevalence of hypertension, diabetes, obesity, arterial stiffness, as well as diastolic dysfunction, may cause endothelial dysfunction and affect pulmonary vasculature. Furthermore, older patients have certain differences in clinical characteristics and outcomes. In this article, the special characteristics of aging in PAH patients have been reviewed, while the risk predictors of elderly patients are also discussed.     

肺动脉高压患者血浆肾上腺髓质素水平与肺动脉压力的关系

目的：探讨肺动脉高压（pulmonary hypertension,PH)患者血浆肾上腺髓质素（a-drenomedullin,AM)的浓度与肺动脉压力的关系。方法：选择正常肺动脉压力患者和轻度、中度、重度肺动脉高压患者各10例，在术中分别从肺动脉和肺静脉中抽血用放射免疫法测定AM含量。结果：肺动脉血浆AM浓度与肺动脉压力呈显著正相关；肺静脉血浆AM浓度低于肺动脉AM浓度，且其浓度差值与肺动脉压力呈显著正相关。结论：AM参与了肺动脉高压的病理生理过程，并在肺内部分代谢，对肺血管张力的调节起重要作用。     

Altered endothelial function in lambs with pulmonary hypertension and acute lung injury

Acute lung injury produces pulmonary hypertension, altered vascular reactivity, and endothelial injury. To determine whether acute lung injury impairs the endothelium-dependent regulation of pulmonary vascular tone, 16 lambs were studied during U46619-induced pulmonary hypertension without acute lung injury, or air embolization-induced pulmonary hypertension with acute lung injury. The hemodynamic responses to endothelium-dependent (acetylcholine, ATP, ET-1, and 4 Ala ET-1 [an ETb receptor agonist]) and endothelium-independent (nitroprusside and isoproterenol) vasodilators were compared. During U46619-induced pulmonary hypertension, all vasodilators decreased pulmonary arterial pressure and vascular resistance (P < 0.05). During air embolization-induced pulmonary hypertension, the pulmonary vasodilating effects of acetylcholine, ATP, and 4 Ala ET-1 were attenuated (P < 0.05); the pulmonary vasodilating effects of nitroprusside and isoproterenol were unchanged; and the pulmonary vasodilating effects of ET-1 were reversed, producing pulmonary vasoconstriction (P < 0.05). During air embolization, the pulmonary vasoconstricting effects of ET-1 were blocked by BQ 123, an ETa receptor antagonist. The systemic effects of the vasoactive drugs were similar during both conditions. We conclude that pulmonary hypertension with acute lung injury induced by air embolization results in endothelial dysfunction; there is selective impairment of endothelium-dependent pulmonary vasodilation and an altered response to ET-1 from pulmonary vasodilation to vasoconstriction. This altered response to ET-1 is associated with decreased ETb receptor-mediated vasodilation and increased ETa receptor-mediated vasoconstriction. Endothelial injury and dysfunction account, in part, for the altered regulation of pulmonary vascular tone during pulmonary hypertension with acute lung injury.