血管紧张素转换酶2在高血压发病机制中的角色

血管紧张素转换酶2是近来被发现肾素-血管紧张素-醛固酮系统中新的代谢酶,不同于血管紧张素转换酶的作用,血管紧张素转换酶2能对血压进行负向调节,对抗血管紧张素转换酶的作用。现对血管紧张素转换酶2的特性及与高血压发病机制中的角色进行综述。     

血管紧张素转换酶2-血管紧张素1-7-Mas轴的心血管效应

经典的肾素-血管紧张素系统在维持动脉血压平衡,水电解质平衡,调节细胞增殖及分化中起着重要的作用.血管紧张素1-7及其在体内主要的合成酶血管紧张素转换酶2,及其受体Mas绀成的调节轴可产生广泛的生理及病理生理学效应.此轴可拮抗血管紧张素转换酶-血管紧张素Ⅱ-血管紧张素Ⅱ 1型受体调节轴的效应,从而为高血压、心力衰竭等心血管疾病及其他系统疾病的药物治疗提供新的思路和方法.     

血管紧张素转换酶2-血管紧张素1—7-Mas轴的心血管效应

经典的肾素-血管紧张素系统在维持动脉血压平衡,水电解质平衡,调节细胞增殖及分化中起着重要的作用。血管紧张素1—7及其在体内主要的合成酶血管紧张素转换酶2,及其受体Mas组成的调节轴可产生广泛的生理及病理生理学效应。此轴可拮抗血管紧张素转换酶-血管紧张素Ⅱ-血管紧张素Ⅱ1型受体凋节轴的效应,从而为高血压、心力衰竭等心血管疾病及其他系统疾病的药物治疗提供新的思路和方法。     

血管紧张素转换酶2研究进展

血管紧张素转换酶2是一种金属钛酶,它将血管紧张素I、血管紧张素Ⅱ分别水解为血管紧张素（1～9）及具有血管舒张、抗增殖的血管紧张素（1～7）。血管紧张素转换酶2参与了肾素-血管紧张素-醛固酮系统中多种肽的代谢过程,与高血压、肾脏疾病、糖尿病等发生相关,对心脏、肾脏有一定保护作用,进一步研究其参与保护的机制,有可能为心血管病治疗提供新的靶点。     

血管紧张素-(1-7)的心血管调节作用

血管紧张素-(1-7)是肾素血管紧张素系统家族中的新成员,近来研究提示其有抗高血压、抑制血管平滑肌增殖和心肌细胞肥大、影响心脏神经电生理、抗血栓形成、调节水、电解质代谢平衡等作用,是血管紧张素Ⅱ(AngⅡ)的内源性拮抗剂。     

血管紧张素转换酶Ⅱ与冠状动脉粥样硬化性心脏病的关系

肾素-血管紧张素系统与心血管疾病的发生发展有着复杂而密切的联系。近年来,一种新的血管紧张素转换酶Ⅱ被发现,血管紧张素转换酶Ⅱ的新的代谢通路对肾素-血管紧张素系统传统代谢通路可能有着负性调节作用,它参与了包括血管:紧张素在内的多种肽的代谢过程,在心血管疾病的病理生理方面发挥着重要作用。最近一些研究表明血管紧张素转换酶Ⅱ在动脉粥样硬化发展过程中起到了保护作用,这为动脉粥样硬化和心血管疾病的治疗和预防提供了新的策略。     

肾素-血管紧张素系统:新成员,新效应

肾素-血管紧张素系统（RAS）通过作用于心血管、肾脏、肾上腺，控制体液、电解质平衡以及动脉压，是机体重要的调控系统。经典的RAS主要成分有肾素、血管紧张素原（AGT）、血管紧张素Ⅰ（AngⅠ）、血管紧张素Ⅱ（AngⅡ）、血管紧张素转换酶（ACE）、血管紧张素受体1（AT1）、血管紧张素受体2（AT2R）。     

血管紧张素转换酶2的研究进展

血管紧张素转换酶2是肾素-血管紧张素系统的一个新成员,是迄今为止发现的第一个人类血管紧张素转换酶同族物。它能水解血管紧张素Ⅰ,生成血管紧张素(1-9),水解血管紧张素Ⅱ,生成血管紧张素(1-7),不仅能调节心血管功能和肾功能,而且在一系列炎症和免疫机制发挥作用的疾病发展过程中起一定作用。现就血管紧张素转换酶2的研究现状进行综述。     

血管紧张素(1-7)对心血管保护作用的研究进展

血管紧张素(1-7)是血管紧张素家族中一个新成员,它通过血管紧张素转换酶Ⅱ/血管紧张素(1-7)/Mas受体轴发挥作用。血管紧张素(1-7)作为血管紧张素Ⅰ的主要活性产物,对调节血管紧张素Ⅱ水平,尤其是组织血管紧张素Ⅱ的水平起着一定的作用。它通过激肽、一氧化氮、前列腺素产生与血管紧张素Ⅱ完全不同的作用。这些提示血管紧张素(1-7)可能是肾素-血管紧张素系统调节自身活性的重要物质。近期研究发现血管紧张素(1-7)具有保护心室心肌功能,降低缺血再灌注损伤和氧化应激,调节神经压力反射,降低血压和舒张血管,抗增殖、抗纤维化和抗炎症反应,以及调节血脂、脂肪细胞代谢、保护糖尿病所致心肌损害等心血管保护作用,现就这些保护作用的新进展做一综述。     

血管紧张素转换酶2基因多态性与肾脏损害

肾素血管紧张素系统（RAS）是体内调节神经体液和心血管功能的主要系统。新发现的多肽酶血管紧张素转换酶2（ACE2）通过产生血管紧张素（Ang）1-7和水解部分AngⅡ,拮抗由ACE水解产物AngⅡ介导的缩血管作用，并抑制血管平滑肌细胞增殖。研究表明糖尿病大鼠肾脏ACE2表达下降，糖尿病、高血压和代谢综合征均可损害肾脏，本研究旨在探讨这三种疾病患者ACE2基因A/C多态分布情况及其与肾脏损害的关系。     

Evidence for cardioprotective,renoprotective, and vasculoprotective effects of vasopeptidase inhibitors in disease

In both the natriuretic peptide and renin-angiotensin systems, peptidases play an important role in the inactivation or activation of the system. Angiotensin-converting enzyme is responsible for the conversion of angiotensin I to angiotensin II, while neutral endopeptidase is one of the pathways involved in the degradation of the natriuretic peptides. The vasopeptidase inhibitors, which simultaneously inhibit neutral endopeptidase and angiotensin-converting enzyme, appear to offer distinct therapeutic advantages in treating hypertension, heart failure, and endothelial dysfunction.     

Targeting the renin-angiotensin system: what's new?

The renin-angiotensin system is a key target for drugs combating cardiovascular disease. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor type-1 (AT1 receptor) blockers are well known. However, angiotensin peptides can be generated through a number of pathways besides the classic system. This review outlines some of these pathways, their relation to the classic system and the likely effect of inhibiting them. Renin is still the key enzyme in angiotensin peptide generation and seems to be the only route to angiotensin I formation in vivo. Renin inhibitors may have some advantages in terms of specificity. Also, by blocking angiotensin I generation, the production of downstream bioactive angiotensin I metabolites should also be blocked. Chymase, a mast cell serine protease, cleaves angiotensin I to produce angiotensin II and may be important at sites of inflammation such as atherosclerotic plaque. Angiotensin-converting enzyme 2 (ACE2), a carboxypeptidase structurally related to ACE but resistant to ACE inhibitors, has a protective effect on cardiac function. Neutral endopeptidase 24.11 breaks down both atrial natriuretic peptide and angiotensin II. Inhibiting it potentiates the action of endogenous atrial peptide but only affects circulating angiotensin II when basal levels are above normal. Dual inhibitors of ACE and endopeptidase 24.11 may be of value where there is both sodium retention and increased angiotensin II. Targeting the renin-angiotensin system by gene therapy or antibody treatment may provide a longer-term treatment for hypertension.     

脂肪组织局部肾素血管紧张素系统与代谢综合征

肾素-血管紧张素系统相关成分陆续在脂肪组织中发现,它们主要受能量代谢调节,与代谢综合征的发生发展有密切关系。在机体发生肥胖、高血压、高血糖和高胰岛素血症时,脂肪组织内肾素-血管紧张素系统表达增加;应用血管紧张素受体拮抗剂或血管紧张素转换酶抑制剂,通过改变脂肪细胞功能等作用,改善代谢综合征的状态。     

Renal response to angiotensin-converting enzyme inhibition

Angiotensin-converting enzyme inhibitors, both teprotide and captopril, induce a potentiated renal vascular response in patients with essential hypertension, and with that a consistent increase in sodium excretion and occasionally an increase in glomerular filtration rate. In patients with advanced congestive heart failure resistant to other vasodilators, a similar triad occurs. It is not yet clear in which settings the renal response to angiotensin-converting enzyme inhibition reflects a reduction in angiotensin II formation—thus implicating the renin-angiotensin system in the pathogenesis—or an additional action, such as a potentiation of the local actions of bradykinin or enhanced prostaglandin formation. Under some circumstances, especially where a qualitatively and quantitatively similar response occurs to angiotensin antagonists and angiotensin-converting enzyme inhibitors or where an angiotensin antagonist prevents an additional response to a converting enzyme inhibitor, it is clear that the specific action of the converting enzyme inhibitor on angiotensin II formation is responsible. Unfortunately, for most responses in animal models and all responses in patients, such rigorous evidence is not yet available.     

The Evolution of Renin-Angiotensin Blockade: Angiotensin-Converting Enzyme Inhibitors as the Starting Point

The renin-angiotensin system has been a target in the treatment of hypertension for close to three decades. Several medication classes that block specific aspects of this system have emerged as useful therapies, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and, most recently, direct renin inhibitors. There has been a natural history to the development of each of these three drug classes, starting with their use as antihypertensive agents; thereafter, in each case they have been employed as end-organ protective agents. To date, there has been scant evidence to favor angiotensin receptor blockers or direct renin inhibitors over angiotensin-converting enzyme inhibitors in treating hypertension or in affording end-organ protection; thus, angiotensin-converting enzyme inhibitors remain the standard of care when renin-angiotensin system blockade is warranted.     

Angiotensin receptor blockers: current status and future prospects

Angiotensin receptor blockers (ARBs), through their physiological blockade of the renin-angiotensin system, reduce morbidity and mortality associated with hypertension, heart failure, myocardial infarction, stroke, diabetic nephropathy, and chronic kidney disease. Among many attributes, excellent tolerability, and their ability to control hypertension for 24 hours with a positive effect on renal function position them as a useful choice for hypertension and related conditions. Because of the widespread actions of the renin-angiotensin system on critical tissues, treatment with ARBs may be beneficial in special populations. Ongoing and future studies will be needed to conclusively determine if ARBs also improve outcomes in patients with heart failure and preserved systolic function, atrial fibrillation, cognitive dysfunction, and kidney transplant recipients. Preliminary clinical data also suggest that combining ARBs and angiotensin-converting enzyme inhibitors may provide a more optimal blockade of the renin-angiotensin system and, therefore, may offer greater cardio- and nephroprotection. Future data will help delineate which ARBs and angiotensin-converting enzyme inhibitors are best combined and which patient populations might benefit from the dual blockade of the renin-angiotensin system.     

Angiotensin-Converting Enzyme 2: Central Regulator for Cardiovascular Function

Angiotensin-converting enzyme 2 (ACE2) is a new component of the renin-angiotensin system (RAS). Accumulating evidence shows that ACE2 provides protective effects in peripheral tissues and has great potential for the treatment of RAS-related diseases. The role of ACE2 in the central nervous system is not well established. However, in recent years, much more progress has been made on the studies of this carboxypeptidase in the central regulation of blood pressure and cardiovascular function in general. It has been shown that brain ACE2 interacts with the other components of the RAS (ACE, angiotensin II, and angiotensin II type 1 receptor), protects baroreflex and autonomic function, stimulates nitric oxide release, reduces oxidative stress, and prevents the development of or attenuates hypertension. These data support the critical role of ACE2 in the central regulation of cardiovascular function. This review summarizes recently published data on the central effects of ACE2 in the regulation of cardiovascular function.     

Pharmacologic modulation of ACE2 expression

Angiotensin-converting enzyme 2 (ACE2) is an enzymatically active homologue of angiotensin-converting enzyme that degrades angiotensin I, angiotensin II, and other peptides. Recent studies have shown that under pathologic conditions, ACE2 expression in the kidney is altered. In this review, we briefly summarize recent studies dealing with pharmacologic interventions that modulate ACE2 expression. ACE2 amplification may have a potential therapeutic role for kidney disease and hypertension.