脂肪组织局部肾素-血管紧张素系统的调节及其在糖尿病中的作用

脂肪组织局部存在肾素-血管紧张素系统(RAS)中几乎所有的组分,这些组分不仅构成局部RAS,而且是循环中RAS各成分的重要来源.多种因素包括肥胖、胰岛素等均可以影响脂肪组织中RAS各成分的表达.脂肪组织局部RAS活性增加,可作用于脂肪细胞,抑制脂肪细胞分化及脂质代谢,并影响脂肪细胞因子分泌,同时血管紧张素可作用于周围组...     

脂肪组织局部肾素-血管紧张素系统的调节及其在糖尿病中的作用

脂肪组织局部存在肾素-血管紧张素系统(RAS)中几乎所有的组分,这些组分不仅构成局部RAS,而且是循环中RAS各成分的重要来源.多种因素包括肥胖、胰岛素等均可以影响脂肪组织中RAS各成分的表达.脂肪组织局部RAS活性增加,可作用于脂肪细胞,抑制脂肪细胞分化及脂质代谢,并影响脂肪细胞因子分泌,同时血管紧张素可作用于周围组织,通过加重炎性反应和氧化应激等途径,导致胰岛素抵抗,参与糖尿病的病理过程.     

肺的肾素-血管紧张素系统

循环肾素一血管紧张素系统(renin-angiotensin system,RAS)是重要的血压和水电解质调节系统.近年来研究发现心脏、血管壁、肾脏和脑等组织局部也具有独立的RAS,主要调节局部组织的生长和分化.我们已经认识到局部RAS在组织损伤和修复过程中起着重要作用.在肺损伤中RAS成分的表达和血管紧张素转化酶的升高提示肺存在RAS,血管紧张素Ⅱ至少在部分上介入肺损伤反应.肺循环和肺实质中局部RAS活化可能影响肺损伤的程度.RAS基因多态性研究以及与特殊表型的关系有助于我们深入了解RAS在肺部的作用,为进一步的靶向治疗提供帮助.     

Ang-(1-7)在急性呼吸窘迫综合征中的肺保护作用

肺组织局部的肾素-血管紧张素系统(RAS)与急性呼吸窘迫综合征(ARDS)关系密切,血管紧张素Ⅱ(AngⅡ)通过其1型受体激活肺部炎症反应,促进ARDS发生发展.血管紧张素-(1-7)[Ang-(1-7)]也是RAS中得重要重要组分之一,能拮抗AngⅡ的生物学作用,被认为是AngⅡ的内源性拮抗剂.在ARDS中,Ang-(1-7)可能通过抑制炎症反应、减轻肺组织纤维化以及抗肺动脉高压等途径发挥肺保护作用,在ARDS中具有广阔的应用前景.     

血管紧张素Ⅱ、炎性反应和2型糖尿病

以往临床研究发现高血压病患者发生2型糖尿病的风险增加,阻断肾素-血管紧张素系统(RAS)对于预防2型糖尿病的发生具有一定的保护作用.近期研究还表明,RAS可能直接参与了糖尿病发生发展过程.炎性反应是肥胖、2型糖尿病等代谢性疾病的重要分子基础.血管紧张素介导的氧化应激、炎性反应水平以及游离脂肪酸的增加在局部和全身都对机体产生重要的影响.     

肾素-血管紧张素系统与肺部疾病关系的研究进展

<正>肾素-血管紧张素系统(Renin-angiotensin system,RAS)是体内重要的体液调节系统,有调节水盐平衡及血压的作用。近年来研究发现,RAS与多种肺部疾病,如肺癌、ALI/ARDS、慢性阻塞性肺疾病、肺动脉高压、肺纤维化等的发生发展存在密切的关系,本文着重综述近年来RAS与肺部疾病关系的研究进展。一、RAS概述肾素-血管紧张素系统(Renin-angiotensin system,RAS)是体内重要的体液调节系统,除存在于循环系统外,也广泛存在肾、肾上腺、心脏、血管、胰腺、     

血管紧张素转移酶2-血管紧张素(1-7)-Mas轴在肾脏疾病发病机制中的作用

肾素-血管紧张素系统(RAS)过度兴奋,尤其是肾脏局部RAS高表达对肾脏疾病发生发展起重要作用.随着对RAS深入研究发现,除经典的RAS途径外,还有一条新的RAS途径:血管紧张素转移酶2-血管紧张素(1-7)-Mas轴[ACE2-Ang(1-7)-Mas轴],它和经典RAS相互作用,共同调节机体内环境稳定、维持肾脏功能正常.本文就ACE2-Ang(1-7)-Mas轴在肾脏生理及疾病中的作用及其机制做一简述.     

肾素-血管紧张素系统与胃癌

肾素血管紧张素系统（renin—angiotensin system，RAS）是体内重要的体液调节系统，越来越多的证据显示，RAS组分与多种肿瘤的发生、发展有关。此文综述了RAS组分在不同胃病变组织中的表达，尤其是其与胃癌发生、发展关系的研究进展。并总结了RAS组分的单核苷酸基因多态性与胃癌易感性的关联。     

肾素血管紧张素系统和血管紧张素Ⅱ信号转导机制的研究进展

肾素血管紧张素系统 (RAS)是一个重要的水电解质平衡调节系统。近年来 ,研究发现除循环RAS外 ,局部组织如心脏、血管壁、肾脏、脑等也具有独立的 RAS,主要调节局部组织的生长和分化 [1]。而且除 Ang 外 ,血管紧张素 1 - 7(Ang1 - 7)也是 RAS中的重要生物活性成分 ,对 Ang 具有反向调节作用 [2 ]。同时 ,随着细胞和分子生物学的发展 ,人们对 Ang 的生成途径和其作用机制有了更加深入的认识 ,对 Ang 信号转导机制的研究取得了一些重大进展。1　RAS以往认为 RAS的主要成分为血管紧张素原、肾素、Ang 、ACE、和 Ang ,近年又增加了 A…     

缬沙坦对心脏局部肾素-血管紧张素系统抑制作用的剂量效应

肾素-血管紧张素系统(renin angiotensin system,RAS)在心血管疾病的发生与发展中具有重要作用,随着研究的不断深入,人们对RAS的认识越来越深入、全面,一些新的RAS成员及作用机制逐渐被发现,局部RAS在心血管疾病中的作用也越来越受到重视。研究发现,组织中的血管紧张素(angiotensin,Ang)Ⅱ大部分在局部组织生成,就心脏而言,心肌肥大、心肌梗死等情况下,AngⅡ的局部浓度可超过血浆浓度,在心脏的病理生理及心功能的调节中发挥重要作用。AngⅡ是RAS的主要活性成分,故与AngⅡ相关的RAS阻断剂在心血管疾病的预防与治疗中作用重大。血管紧张素Ⅱ受体拮抗剂(angiotensin receptor blocker,ARB)作为一类临床常用的RAS阻断剂,其心血管保护作用已得到广泛研究,但大型临床试验中药物的剂量水平存在差异,研究结果并不一致。目前唯一一项对不同剂量ARB的心脏保护作用进行直接比较的大型临床研究——HEAAL研究证实,高剂量较低剂量可使心力衰竭患者获益更大。本文对ARB相关基础和临床文献进行查找与分析,并探讨缬沙坦对心脏RAS抑制作用的剂量效应。     

Role of the renin-angiotensin system in prostate cancer

Prostate cancer is highly prevalent in Western society, and its early stages can be controlled by androgen ablation therapy. However, the cancer eventually regresses to an androgen-independent state for which there is no effective treatment. The renin-angiotensin system (RAS), in particular the octapeptide angiotensin II, is now recognised to have important effects on growth factor signalling and cell growth in addition to its well known actions on blood pressure, fluid homeostasis and electrolyte balance. All components of the RAS have been recently identified in the prostate, consistent with the expression of a local RAS system in this tissue. This review focuses on the role of the RAS in the prostate, and the possibility that this pathway may be a potential therapeutic target for the treatment of prostate cancer and other prostatic diseases.     

Local adipose tissue renin-angiotensin system

A local renin-angiotensin system (RAS) has been proposed in adipocytes. Adipocytes are a suggested source of components of the RAS, with regulation of their production related to obesity-hypertension. Both angiotensin type 1 and 2 receptors have been localized to adipocytes. Angiotensin II has been demonstrated to regulate adipocyte growth and differentiation, lipid metabolism, and expression and release of adipokines and RAS components, and to promote oxidative stress. Differences in regional expression of RAS components in visceral versus subcutaneous adipose tissue have been suggested as a link between abdominal obesity and cardiovascular disease. Finally, several studies support antihypertensive efficacy of RAS blockade in patients with type 2 diabetes and obesity. Future studies should address the role of adipocyte-specific deficiency of RAS components to definitively determine the relevance of the adipose RAS to normal physiology and to the development of hypertension.     

The renin-angiotensin system and male reproduction: new functions for old hormones

The blood-borne renin-angiotensin system (RAS) is known best for its role in the maintenance of blood pressure and electrolyte and fluid homeostasis. However, numerous tIssues show intrinsic angiotensin-generating systems that cater for specific local needs through actions that add to, or differ from, the circulating RAS. The male reproductive system has several sites of intrinsic RAS activity. Recent focus on the epididymis, by our laboratories and by others, has contributed important details about the local RAS in this tIssue. The RAS components have been localized morphologically and topographically; they have been shown to be responsive to androgens and to hypoxia; and angiotensin has been shown to influence tubular, and consequently, fluid secretion. Components of the RAS have also been found in the testis, vas deferens, prostate and semen. Angiotensin II receptors, type 1 and, to a lesser extent, type 2 are widespread, and angiotensin IV receptors have been localized in the prostate. The roles of the RAS in local processes at these sites are still uncertain and have yet to be fully elucidated, although there is evidence for involvement in tubular contractility, spermatogenesis, sperm maturation, capacitation, acrosomal exocytosis and fertilization. Notwithstanding this evidence for the involvement of the RAS in various important aspects of male reproduction, there has so far been a lack of clinical evidence, demonstrable by changes in fertility, for a crucial role of the RAS in male reproduction. However, it is clear that there are several potential targets for manipulating the activity of the male reproductive system by interfering with the locally generated angiotensin systems.     

Local stress, not systemic factors, regulate gene expression of the cardiac renin-angiotensin system in vivo: a comprehensive study of all its components in the dog.

Cardiac hypertrophy is associated with altered expression of the components of the cardiac renin-angiotensin system (RAS). While in vitro data suggest that local mechanical stimuli serve as important regulatory modulators of cardiac RAS activity, no in vivo studies have so far corroborated these observations. The aims of this study were to (i) examine the respective influence of local, mechanical versus systemic, soluble factors on the modulation of cardiac RAS gene expression in vivo; (ii) measure gene expression of all known components of the RAS simultaneously; and (iii) establish sequence information and an assay system for the RAS of the dog, one of the most important model organisms in cardiovascular research. We therefore examined a canine model of right ventricular hypertrophy and failure (RVHF) in which the right ventricle (RV) is hemodynamically loaded, the left ventricle (LV) is hemodynamically unloaded, while both are exposed to the same circulating milieu of soluble factors. Using specific competitive PCR assays, we found that RVHF was associated with significant increases in RV mRNA levels of angiotensin converting enzyme and angiotensin II type 2 receptor, and with significant decreases of RV expression of chymase and the angiotensin II type 1 receptor, while RV angiotensinogen and renin remained unchanged. All components remained unchanged in the LV. We conclude that (i) dissociated regional regulation of RAS components in RV and LV indicates modulation by local, mechanical, not soluble, systemic stimuli; (ii) components of the cardiac RAS are independently and differentially regulated; and (iii) opposite changes in the expression of angiotensin converting enzyme and chymase, and of angiotensin II type I and angiotensin II type 2 receptors, may indicate different physiological roles of these RAS components in RVHF.     

The adipose renin–angiotensin system: Role in cardiovascular disease

Several reviews have highlighted the importance of local tissue production of components of the renin–angiotensin system (RAS) [Bader, M., Ganten, D., 2008. Update on tissue renin–angiotensin systems. J. Mol. Med. 86, 615–621; Krop, M., Danser, A.H., 2008. Circulating versus tissue renin–angiotensin system: on the origin of (pro)renin. Curr. Hypertens. Rep. 10, 112–118; Paul, M., Poyan Mehr, A., Kreutz, R., 2006. Physiology of local renin–angiotensin systems. Physiol. Rev. 86, 747–803]. While the concept of tissue RAS is gaining more widespread acceptance, the concept of local angiotensin II (AngII) production, acting in coordinate or independently of the endocrine RAS, continues to be debated. The primary reasons that local AngII production has been studied by many investigators are that components of the RAS are expressed by multiple cell types, and that the endocrine RAS cannot fully explain all effects of AngII. Moreover, through the development and study of genetically altered models for over-expression or knockdown of individual RAS components within specific cell types, it is becoming increasingly more evident that local RAS contribute to effects of AngII in normal physiology and disease. The purpose of this review is to define the presence and physiological significance of a local RAS in adipose tissue in relation to cardiovascular disease.     

Role of the local renin-angiotensin system in cardiac damage: a minireview focussing on transgenic animal models

The local generation of all components of the renin-angiotensin system (RAS) in the heart has been the basis for the postulation of a tissue RAS in this organ. Since angiotensin II is involved in the induction of cardiac hypertrophy and fibrosis the local generation of this peptide may be of highest clinical importance. Several transgenic animal models have been generated to evaluate the functional importance of the cardiac RAS. We have established a new hypertensive mouse model lacking local angiotensinogen expression in the heart. In these animals, cardiac weight and collagen synthesis are increased compared to normotensive control mice but to a lesser extent than in mice with equally enhanced blood pressure but intact cardiac angiotensinogen generation. Thus, we have shown that local synthesis of this protein is involved but not essential in the development of cardiac hypertrophy and fibrosis.     

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。