血管紧张素Ⅱ受体拮抗剂的临床研究进展

血管紧张素受体拮抗剂能特异性地与血管紧张素Ⅱ受体结合 ,从而可以阻断所有已知与高血压和心血管并发症有关的血管紧张素Ⅱ作用 ,其治疗高血压的疗效与目前一线降压药物相同 ,但不良反应低。     

血管紧张素Ⅱ受体拮抗剂与肾脏病

血管紧张素Ⅱ对慢性肾脏疾病进展具有重要作用，血管紧张素Ⅱ的Ⅰ型受体拮抗剂可阻断血管紧张素Ⅱ的作用，有可能性可为一类新的肾脏保护药物。本文从动物实验和临床研究方面总结血管紧张素Ⅱ受体拮抗剂对肾脏病的作用。     

血管紧张素Ⅱ受体及受体拮抗剂研究进展

AngⅡ是RAS中最为重要的活性激素，它在高血压的病理生理中起着重要的作用。细胞膜表面的AngⅡ受体是AngⅡ功能的主要介导。目前已证实有两种特异性AngⅡ受体亚型：AT1受体和AT2受体。业已确定的AT1受体有两个亚型：AT1A受体和AT1B受体。AT1受体和AT2受体最主要的区别在于AT1受体是能被Losartan选择性抑制的受体，     

血管紧张素II受体拮抗剂与肾脏病

血管紧张素II对慢性肾脏疾病进展具有重要作用 ,血管紧张素II的I型受体拮抗剂可阻断血管紧张素II的作用 ,有可能性成为一类新的肾脏保护药物。本文从动物实验和临床研究方面总结血管紧张素II受体拮抗剂对肾脏病的作用。     

血管紧张素Ⅱ受体及其特异性拮抗剂的研究进展

血管紧张素Ⅱ（ＡｎｇⅡ）为肾素血管紧张素系统（ＲＡＳ）的重要生物活性肽，除参与正常血管张力、维持水盐平衡调节外，由局部ＲＡＳ产生的ＡｎｇⅡ还参与了局部组织细胞的功能及生长的调节。并在某些心血管疾病如高血压、心肌肥厚、充血性心衰、缺血性心肌病及肾功能不全等病理过程发生发展中起着重要作用。ＡｎｇⅡ主要通过激活特异性受体而发挥其生物学效应。它有ＡＴ１和ＡＴ２两个亚型。ＡＴ１受体能被非肽类ＡｎｇⅡ受体拮抗剂Ｌｏｓａｒｔｅｎ特异性阻断，而ＡＴ２受体能被其拮抗剂ＰＤ１２３１７７、ＰＤ１２３３１９及ＣＧＰ４２１１２Ａ等特异性阻断。两种受体在不同组织或同一组织的不同细胞介导ＡｎｇⅡ复杂的生物学效应。     

血管紧张素Ⅱ受体研究概况

Ｒ－Ａ系统一直备受注目，本文从分子水平和基因水平对Ｒ－Ａ系统中新的热点：血管紧张素受体的研究进行了综述。     

Ⅰ型血管紧张素Ⅱ受体基因多态性与福建地区高血压的关系

血管紧张素 (angiotensin ,Ang )是已知内源性升压物质中作用最强的激素之一 ,在高血压发病中起着重要作用。Ang 的绝大多数生物学作用是由 型受体 (AT1 R)介导的 [1 ]。1994年 Bonnardeaux等 [2 ]发现在高血压患者中 AT1 R基因C1 1 6 6 等位基因频率高于正常者。目前国内有关研究不多 ,样本数均较少 ,结论不一 [3 ,4] ,我们对福建地区人群进行了研究 ,报告如下。1　对象与方法1.1　对象　均为福建地区汉族人。其中原发性高血压患者 12 0例 ,来自本院心内科 ,高血压按 WHO诊断标准 ,排除冠心病、糖尿病及继发性高血压 ,高血压家族…     

血管紧张素Ⅱ受体拮抗剂联合中成药治疗 慢性肾炎蛋白尿的研究进展

慢性肾炎基本临床表现为蛋白尿、血尿、高血压、水肿,其中蛋白尿是加速肾小球硬化、促进肾功能恶化的重要因素之一,且蛋白尿水平越高,导致肾脏病进展的速度越快,因此积极降低蛋白尿是肾脏病治疗的关键。血管紧张素Ⅱ受体拮抗剂除降压作用外,还有降低患者蛋白尿水平及肾脏保护作用,为进一步减少慢性肾炎蛋白尿,在应用ARB基础上加用中成药亦可获得疗效进行综述。     

血管紧张素II对巨噬细胞(THP-1细胞)凝集素样氧化低密度脂蛋白受体表达的影响

目的:研究AngII对人单核/巨噬细胞(THP-1细胞)凝集素样氧化低密度脂蛋白受体(LOX-1)蛋白表达和基因转录的影响,从细胞蛋白、分子水平探讨AngII和巨噬细胞LOX-1相互之间的关系,以进一步了解两者在动脉粥样硬化中的地位。方法:将不同浓度AngII(1×10^-9-1×10^-5mol/L)与经0.1μmol/L佛波酯(PMA)诱导分化后的THP-1细胞共孵育24h,以及将1×10^-6mol/L浓度的AngII与诱导分化后的THP-1细胞作用不同时间0、3、6、12、24、48h后,用细胞酶联免疫法和半定量RT-PCR分别检测LOX-1蛋白和mRNA表达的情况。结果:未经诱导的THP-1细胞不表达LOX-1mRNA;而经PMA诱导后,THP-1细胞停止增殖,由单核细胞分化成为巨噬细胞,并表达LOX-1mRNA。不同浓度的AngII作用诱导分化后的THP-1细胞24h,细胞LOX-1蛋白和mRNA的表达呈浓度依赖性显著增加。同一浓度的AngII作用THP-1细胞,可呈时间依赖性诱导LOX-1蛋白和mRNA表达,其趋势是3h左右开始增加,24h左右至最高峰,之后逐渐减低。结论:经PMA诱导分化后的THP-1细胞表达LOX-1;AngII能明显增强分化后的THP-1细胞表达LOX-1蛋白和mRNA,并呈浓度和时间依赖性。AngII这种作用可能是促进动脉粥样硬化发生、发展的机制之一。     

血管紧张素II及其受体在血管平滑肌细胞迁移中的作用

目的:探讨血管紧张素II(AngII)及其受体(ATRs)在局部血管损伤后血管平滑肌细胞(VSMC)迁移中的作用及其机制。方法:以体外培养VSMC为基础,采用细胞化学和改良Boyden'schamber的方法,观察AngⅡ干预VSMC后AngII受体的表达、VSMC迁移能力的变化、肌动蛋白纤维丝的动态组装变化,并探讨AT₁R拮抗剂、AT₂R拮抗剂对上述观测指标的影响。结果:AngII10^-7mol/L可以刺激VSMC发生迁移,该作用是通过影响VSMC内应力纤维动态组装而实现的;AngII干预VSMC后可使AT₁R表达上调,随着作用时间延长AT₁R表达水平下降。AT₁R拮抗剂可下调AT₁R表达。AngII通过AT₁R的介导发挥其影响VSMC迁移能力的生物学效应。AT₂R对此无明显影响。结论:AngII通过AT₁R介导来调节VSMC内肌动蛋白微丝的动态组装,进而改变VSMC的迁移能力,从而发挥其介导VSMC迁移的生物学效应。     

Cardiovascular and adrenal sensitivity to angiotensin II in essential hypertension

Summary Regulation of aldosterone secretion by sodium chloride is impaired in a group of essential hypertensives: high-salt diet fails to suppress aldosterone in these patients despite low renin values. The mechanism of this impaired regulation of aldosterone has not been clarified so far. We tested the sensitivity of aldosterone secretion and blood pressure to A II in 20 normotensive controls (aged 20–60, MAP 92±3 mm Hg), in ten normotensives with one or two parents with hypertension, and in 21 patients with essential hypertension (aged 17–65, MAP 119±4 mm Hg). After a period of 6 days on high-salt intake (300–320 mEq Na⁺/day), A II (0.1, 0.5, 1.0 and 2.0 ng/kg/min) was infused, each concentration for 30 min. According to aldosterone excretion during sodium loading, patients were divided into group A with complete suppression (n=12, aldosterone excretion 3.6±0.4 µg/day) and in group B with insufficient suppression (n=9, aldosterone excretion 15.5±2.3 µg/day). Despite similarly low plasma renins, rise of serum aldosterone levels during A II infusion was significantly higher in group B patients than in group A patients and normotensive controls. Rise in mean arterial blood pressure, however, brought about by graded A II infusion was similar in both groups of hypertensives and in normotensive controls. The results demonstrate an increased adrenal sensitivity to A II in a subgroup of essential hypertensives only. A similar adrenal hypersensitivity to A II found by others in patients with hyperaldosteronism due to adrenal hyperplasia supports the hypothesis that the same mechanism underlies both disorders.Abbreviations MAP mean arterial blood pressure - A II Angiotensin II Dedicated to Prof. Dr. W. Kaufmann on the occasion of his 60^th birthday     

肾性高血压血管重构中血红素加氧酶的作用

目的：研究血红素加氧酶（HO）在肾性高血压所致的血管重构中的作用。方法：采用两肾一夹（2K1C）肾性高血压大鼠模型，测定术后4周主动脉中膜的厚度、主动脉组织HO活性及HO-1蛋白表达水平。结果：① 2K1C肾性高血压大鼠术后2周开始出现高血压，在术后4周血压稳定升高；Hemin组术后4周未见血压升高。②术后4周2K1C组大鼠可见主动脉中膜的厚度较假手术组高27.5％（P<0.01）； Hemin组主动脉中膜的厚度较2K1C组低16.1％（P<0.01）。③术后4周2K1C组主动脉组织HO-1蛋白表达量明显高于假手术组（P<0.01）；HO酶活性高于假手术组（P<0.05）。结论：肾性高血压导致血管重构的过程中HO系统激活。诱导HO可以降低肾性高血压大鼠的血压，抑制主动脉中膜平滑肌层的增厚。     

血管紧张素II和洛沙坦对肝星状细胞合成胶原的影响

目的 :探讨血管紧张素II及其 1型受体 (AT1a)拮抗剂洛沙坦 (losartan) ,对肝星状细胞合成胶原的影响。方法 :①大鼠肝星状细胞的分离、培养及鉴定 ;②在不同浓度的血管紧张素II和洛沙坦作用下 ,采用 [3 H]-脯氨酸掺入释放法分别检测肝星状细胞生成胶原的情况。结果 :①细胞得率为 2× 10 7- 3× 10 7个 /只 ,活力在 95 %以上 ,纯度超过 90 %。②血管紧张素II在浓度为 10 -6mol/L - 10 -10 mol/L时 ,肝星状细胞生成胶原明显增多 (P <0 0 5 ) ;血管紧张素II浓度与胶原量呈正相关 (r=0 96 0 ,P <0 0 1)。洛沙坦在浓度为 10 -6mol/L - 10 -9mol/L时 ,胶原生成量显著减少 (P <0 0 5 ) ;且浓度与胶原生成量呈负相关 (r=- 0 882 ,P <0 0 1)。结论 :血管紧张素II可以促使肝星状细胞产生大量的胶原 ;洛沙坦通过拮抗AT1a后 ,胶原合成量显著减少 ,提示血管紧张素II在促使肝纤维化的发展过程中起着重要的作用 ,AT1a的拮抗剂有望为阻止肝纤维化发展提供新策略     

Genetic deletion and overexpression of angiotensin II receptors

Angiotensin II receptors are essential components of the renin-angiotensin system transducing angiotensin II mediated signals across the plasma membrane of many cell types in the cardiovascular system. To date, three subtypes of angiotensin II receptors have been identified by molecular cloning, termed angiotensin II type 1 (AT_1A, AT_1B) and type 2 (AT₂) receptors. This review focuses on recent transgenic animal models which have been generated to study the in vivo significance of angiotensin receptor diversity. AT_1A receptors are the major blood pressure regulators and have a potent growth-stimulatory effect on cardiac myocytes in vivo. The AT_1B receptor subtype may participate in the control of vascular tone if AT_1A receptors are absent. AT₂ receptors are abundantly expressed during embryonic development and may also play a role in blood pressure regulation by influencing vascular development and differentiation. Received: 16 February 1998 / Accepted: 10 August 1998     

坎地沙坦阻断血管紧张素Ⅱ介导的原代急性髓样白血病细胞增殖的作用及机制

目的: 观察血管紧张素Ⅱ 1型受体(AT1R)拮抗剂坎地沙坦抑制血管紧张素Ⅱ(Ang Ⅱ)介导的原代急性髓样白血病(AML)细胞增殖的作用及机制。方法: MTT法观察Ang Ⅱ对原代AML细胞、正常骨髓单个核细胞增殖的影响以及坎地沙坦和AT2R拮抗剂 PD123319对AngII促原代AML细胞增殖的拮抗作用; Western blotting法观察坎地沙坦和PI3K抑制剂对原代AML细胞Akt磷酸化的影响。结果: AngII能剂量和时间依赖性促进原代AML细胞增殖(P<0.05),而对正常骨髓无此作用。坎地沙坦随浓度和时间依赖性阻断Ang II作用下白血病细胞增殖(P<0.05)。PI3K抑制剂可抑制Ang II促进原代AML细胞的增殖(P<0.05),坎地沙坦能明显下调Ang II增加原代AML细胞Akt的磷酸化水平(P<0.05)。结论: 坎地沙坦通过抑制PI3K/Akt信号转导途径抑制Ang II/AT1R介导的白血病细胞增殖。     

Cardiovascular and renal effects of intracerebroventricular angiotensin II in conscious sheep

Effects on systemic and pulmonary haemodynamics, renal electrolyte excretion, and plasma concentration of vasopressin, catecholamines, electrolytes and proteins in response to intracerebroventricular infusions of [Val⁵]-angiotensin II (ANG II) at 1, 2 and 4 pmol kg^-1min^-1in isotonic saline for 30 min were studied in conscious sheep (n = 6). Vehicle control infusions were performed in four of the animals. All three doses of ANG II were expected to increase CFS concentration of the peptide above physiological levels. All ANG II infusions were noticed to be dipsogenic, but the animals were not allowed to drink freely until at the end of the experiments (at 120 min post-infusion). The systemic arterial blood pressure increased significantly only in response to 2 and 4 pmol kg^-1min^-1, concomitant with an increase of the systemic vascular resistance, whereas the cardiac output and heart rate remained unchanged. The central venous pressure increased only after administration of the highest ANG II dose, while pulmonary artery, and capillary wedge pressures were unaffected during all experiments. The plasma protein and K concentration fell in response to ANG II administration. Also here, the effects were significant only at 2 and 4 pmol kg^-1min^-1. The plasma levels of vasopressin, noradrenaline, adrenaline and dopamine did not change significantly in response to any of the infusions. The renal Na excretion increased by 100–400%, but not in a strictly dose-dependent manner. Much smaller and more variable effects were seen on the renal K excretion. We conclude that: (1) supraphysiological CSF ANG II levels are needed to cause a pressor effect when the peptide is administered via the intracerebroventricular route in conscious sheep; (2) the blood pressure is increased exclusively via peripheral vasoconstriction and; (3) increased vasopressin release does not contribute to the cardiovascular changes. The results also demonstrate that ANG II may cause haemodilution via a central site of action.     

Chronic intermittent hypoxia augments chemoreflex control of sympathetic activity: Role of the angiotensin II type 1 receptor

Chronic exposure to intermittent hypoxia (CIH) increases carotid sinus nerve activity in normoxia and in response to acute hypoxia. We hypothesized that CIH augments basal and chemoreflex-stimulated sympathetic outflow through an angiotensin receptor-dependent mechanism. Rats were exposed to CIH for 28 days: a subset was treated with losartan. Then, lumbar sympathetic activity was recorded under anesthesia during 20-s apneas, isocapnic hypoxia, and potassium cyanide. We measured carotid body superoxide production and expression of angiotensin II type-1 receptor, neuronal nitric oxide synthase, and NADPH oxidase. Sympathetic activity was higher in CIH vs. control rats at baseline, during apneas and isocapnic hypoxia, but not cyanide. Carotid body superoxide production and expression of angiotensin II type 1 receptor and gp91^phox subunit of NADPH oxidase were elevated in CIH rats, whereas expression of neuronal nitric oxide synthase was reduced. None of these differences were evident in animals treated with losartan. CIH-induced augmentation of chemoreflex sensitivity occurs, at least in part, via the renin–angiotensin system.