哮喘小鼠肺脏组织肾素-血管紧张素系统相关组分表达 及AT1R拮抗剂对其影响

目的：探讨肾素-血管紧张素系统（RAS）与哮喘发生的关系,为哮喘发病机制的研究和治疗提供理论依据。方法：复制小鼠哮喘模型,小鼠分为对照组、模型组、坎地沙坦低剂量组及高剂量组,采集小鼠血清,测量血清中血管紧张素Ⅱ (AngⅡ)与血管紧张素Ⅰ(AngⅠ)的含量;通过Western blotting和RT-PCR观察RAS中血管紧张素原(AGT)、血管紧张素转换酶(ACE)、血管紧张素Ⅱ 1型受体（AT₁R）和2型受体（AT₂R）在各组小鼠肺组织中的表达。结果：模型组小鼠血清AngⅡ含量较对照组增高（P<0.05）,坎地沙坦组与模型组比较无明显变化（P>0.05）。各组小鼠血清中AngⅠ含量比较差异无统计学意义（P>0.05）。模型组小鼠AT1R和ACE蛋白表达较对照组明显增加（P<0.05）,坎地沙坦组AT₁R表达与模型组比较明显降低(P<0.05),ACE无明显变化（P>0.05）。AT₂R蛋白表达各组间比较差异无统计学意义（P>0.05）。模型组小鼠ACE mRNA表达较对照组明显增加（P<0.05）,坎地沙坦组与模型组比较差异无统计学意义（P>0.05）。模型组小鼠AT1R mRNA表达较对照组明显增加（P<0.05）,坎地沙坦组较模型组明显降低（P<0.05）。模型组AT2R mRNA较对照组明显降低（P<0.05）,坎地沙坦组较模型组明显增加（P<0.05）。各组AGT mRNA表达无明显变化（P>0.05）。  结论：在小鼠哮喘发病过程中,RAS活化参与了哮喘的发病过程,并且AT₁R拮抗剂坎地沙坦可以逆转ACE、AT₁R和AT₂R表达的改变。     

Role of angiotensin Ⅱ and angiotensin Ⅱ receptors in vascular smooth muscle cell migration in vitro

ObjectiveTo determine the biotic effects of angiotensin Ⅱ (Ang Ⅱ) on the migration of rat smooth muscle cells (VSMCs) and investigate the mechanisms involved in the development of vascular injury. Methods VSMCs isolated from aortic media of Wistar rats and cultured by the modified explant method were adopted. In the presence and absence of Ang Ⅱ, the expression of Ang Ⅱ receptor (ATR) and reorganization of the actin cytoskeleton and focal adhesion of VSMCs were studied by an immunocytochemistry technique and fluorocytochemistry technique. Migration assays were performed with a modified Boyden’s chamber. The effects of AT(1)R antagonist (CV- 11974), AT2R antagonist (PD123319) on the aforementioned target were studied. Results VSMCs migration was stimulated by adding Ang Ⅱ. The dynamic reorganization of actin cytoskeleton and focal adhesions may be an important mechanism by which Ang Ⅱ facilitates VSMCs motility. The expression of AT(1)R in VSMCs could be upregulated initially after treatment with Ang Ⅱ, then decreased gradually. The expression of AT(1)R was downregulated by AT(1)R antagonists. The effect of Ang Ⅱ on VSMCs migration was mediated by AT(1)R, while AT2R had no significant effect. Conclusions The dynamic reorganization of focal adhesions and the actin cytoskeleton is required for Ang Ⅱ- induced VSMCs migration. This effect is mediated by AT(1)R.     

糖尿病大鼠脑内血管紧张素Ⅱ含量及其1型受体表达的变化

目的了解糖尿病（diabetes mellitus，DM）大鼠脑内血管紧张素Ⅱ（AngⅡ）含量及其1型受体（ATD表达的改变。方法以链脲佐菌素（STZ）诱导的DM大鼠为研究对象。采用免疫组化观测大鼠脑内AT1的表达；用放射免疫分析法测定血浆及脑组织AngⅡ的含量。结果DM发生14天后，血浆和下丘脑的AngⅡ含量升高，延髓AngⅡ含量降低，视上核（SON）、室旁核（PVN）、孤束核（NST）的AT1表达显著增强，而穹隆下器官（SFO）的AT1表达则显著减弱。结论DM大鼠的中枢和血浆的AngⅡ含量及AT1在脑内的表达有异常改变。     

氟伐他汀对血管紧张素Ⅱ诱导的系膜细胞AT1受体和Ⅳ型胶原表达的影响

目的:观察血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导的正常大鼠肾小球系膜细胞(HBZY-1)血管紧张素Ⅱ1型受体(angiotensinⅡtype 1 receptor,AT1R)蛋白和Ⅳ型胶原(ColⅣ)蛋白的表达情况及氟伐他汀对AT1R和ColⅣ表达的影响,探讨其肾脏保护作用的可能机制。方法:将HBZY-1细胞分为3组:①阴性对照组;②不同浓度(0.1,1.0,10μmol/L)AngⅡ刺激组;③1.0μmol/L AngⅡ加不同浓度(0.1,1.0,10μmol/L)氟伐他汀干预组,蛋白质印迹法检测各组AT1R蛋白的表达,酶联免疫吸附实验(ELISA法)检测各组ColⅣ蛋白的表达。结果:AngⅡ刺激后,HBZY-1细胞AT1R及ColⅣ的表达随AngⅡ浓度增加而增强;氟伐他汀能够剂量依赖性地抑制AT1R和ColⅣ的表达。结论:氟伐他汀能够抑制AngⅡ诱导的HBZY-1细胞AT1R和ColⅣ的表达,同时AT1R和ColⅣ的表达存在正相关,推断氟伐他汀可能通过下调AT1R影响ColⅣ的表达,进而改善高血压肾脏硬化。     

Effect of angiotensin Ⅱ and angiotensin Ⅱ type 1 receptor antagonist on the proliferation,contraction and collagen synthesis in rat hepatic stellate cells

Background Angiotensin Ⅱ （Ang Ⅱ） is a very important vasoactive peptide that acts upon hepatic stellate cells （HSCs）, which are major effector cells in hepatic cirrhosis and portal hypertension. The present study was aimed to investigate the effects of Ang Ⅱ and angiotensin Ⅱ type 1 receptor antagonist （AT1RA） on the proliferation, contraction and collagen synthesis in HSCs.
Methods HSC-T6 rat hepatic stellate cell line was studied. The proliferation of the HSC cells was evaluated by MTT colorimetric assay while HSC DNA synthesis was measured by ^3H-thymidine incorporation. The effects of angiotensin Ⅱ and AT1RA on HSCs contraction were studied by analysis of the contraction of the collagen lattice. Cell culture media were analyzed by RT-PCR to detect secretion of collagen Ⅰ （Col Ⅰ）, collagen Ⅲ （Col Ⅲ） and transforming growth factor β1 （TGF-β1） by enzyme linked immunosorbent assay. HSC was harvested to measure collagen Ⅰ, collagen Ⅲ and tissue inhibitor of metalloproteinase-1 （TIMP-1） mRNA expression.
Results Ang Ⅱ （（1×10^-10-1×10^-4）mol/L）stimulated DNA synthesis and proliferation in HSCs compared with untreated control cells. AT1RA inhibited angiotensin Ⅱ induced proliferation of HSCs. A linear increase in the contractive area of collagen lattice correlated with the concentration of angiotensin Ⅱ （1×10^-9-1×10^-5 mol/L） and with time over 48 hours. AT1RA blocks angiotensin Ⅱ induced contraction of collagen lattice. Col Ⅰ, Col Ⅲ and TGF-β1 levels of the Ang Ⅱ group were higher than those of control group and this increase was downregulated by AT1RA. The mRNA expressions of Col Ⅰ, Col Ⅲ and TIMP-1 were higher in HSCs from the Ang Ⅱ group than the control group and downregulated by AT1RA.
Conclusions Angiotensin Ⅱ increased DNA synthesis and proliferation of HSCs in a dose-dependent manner, stimulated the contraction of HSCs dose- and time-dependently. Angiotensin also promoted excretion of Col I, Col Ⅲ and TGF-β1 lev     

同型半胱氨酸在大鼠血管平滑肌细胞上通过激活ERK1/2信号通路促进血管紧张素Ⅱ受体1表达

目的：在原代大鼠血管平滑肌细胞(VSMC)上观察同型半胱氨酸(Hcy)对血管紧张素II受体1(AT1R)的蛋白表达的影响。     

不同剂量食用白酒对大鼠心脏功能和血管紧张素Ⅱ的影响

目的 观察摄入不同剂量53°食用白酒对大鼠收缩压、左心室内压及血管紧张素Ⅱ及其1型受体的影响.方法 成年雄性SD大鼠24只,用简单随机抽样方法随机分为低剂量组、高剂量组和正常对照组.低剂量和高剂量分别给予4mL· kg-1·d-1、8mL·kg-1·d-1的53°食用白酒灌胃,对照组给予等体积量生理盐水(4mL·kg-1·d-1)灌胃.灌胃60天后,利用BL-420S生物信号系统测定收缩压和左室内压;光镜、电镜下观察心肌细胞形态;逆转录聚合酶联反应方法检测心肌血管紧张素( AngⅡ)1型受体(AT1) mRNA表达;放射免疫法测定血浆血管紧张素Ⅱ含量.结果 ①高剂量组的收缩压、左心室内压与低剂量组、正常对照组比较无统计学意义(P＞0.05);②光镜下高剂量组的心肌细胞有部分区域空泡样变性,电镜下可见高剂量组心肌细胞核水肿、部分出现双核仁、线粒体明显肿胀;③各组间血浆血管紧张素Ⅱ含量比较没有统计学意义(P＞0.05);④高剂量组AT1受体mRNA表达比低剂量组正常对照组降低(P＜0.05).结论 摄入高剂量白酒2个月,可致心肌结构发生改变,并引起心肌AT1 mRNA表达降低.     

INHIBITORY EFFECT OF ANGIOTENSIN Ⅱ TYPE 1 RECEPTOR-ASSOCIATED PROTEIN ON VASCULAR SMOOTH MUSCLE CELL GROWTH AND NEOINTIMAL FORMATION

Objective To investigate the mechanism of a novel angiotensin Ⅱ type 1 receptor-associated protein （ATRAP） interfering with angiotensin Ⅱ type 1 （AT1） receptor-mediated vascular smooth muscle cell （VSMC） growth and neointimal formation. Methods VSMCs isolated from thoracic aorta of adult Sprague-Dawley （SD） rats were used in this study. ATRAP cDNA was subcloned into pcDNA3 vector and then transfected into VSMCs. DNA synthesis and extracellular signal-regulated kinase （ERK） and phospho-ERK expressions in VSMCs were assayed by measurement of ^3H thymidine incorporation and Western blotting, respectively. Morphological changes were observed in the balloon injured artery with or without transfection of ATRAP cDNA using 12-week-old male SD rats. Results ATRAP overexpression in VSMCs inhibited angiotensin Ⅱ （Ang Ⅱ）-induced ^3H thymidine incorporation 48 hours after Ang Ⅱ stimulation （ P 〈 0. 05 ）. In VSMC, Ang Ⅱ stimulation increased the phosphorylation of ERK, which reached the peak around 60 minutes. The activation of phospho-ERK was significantly decreased by ATRAP （ P 〈 0. 05 ）. Neointimal formation was markedly inhibited by ATRAP overexpression in injuried arteries. Conclusions The AT1 receptor-derived activation of ERK plays an essential role in Ang Ⅱ-induced VSMC growth. The growth inhibitory effects of ATRAP might be due to interfering with AT1 receptor-mediated activation of ERK in VSMC growth and neointimal formation.     

氯沙坦对糖尿病大鼠肾组织血管紧张素Ⅱ及其1型受体mRNA表达的影响

目的研究氯沙坦对实验性糖尿病大鼠肾组织血管紧张素Ⅱ(AngⅡ)1型受体mRNA表达的影响。方法纯种雄性Wistar大鼠分为3组,A组(n=11)为正常对照组,B组(n=11)为糖尿病为干预组,C组(n=9)为糖尿病大鼠氯沙坦干预组。以链脲佐菌素制备糖尿病大鼠模型。饲养18周后取出肾脏检测AngⅡ水平、AngⅡ1型受体mRNA表达,收集24h尿测定尿白蛋白排泄及肌酐并心脏内取血检测血AngⅡ及肌酐。AngⅡ1型受体mRNA表达采用RT-PCR,以-actin作为内对照。尿白蛋白排泄采用大鼠白蛋白特异的酶免疫分析试剂盒。结果血、肾组织AngⅡ在A、B、C三组间无显著性差异。肾组织AngⅡ1型受体mRNA表达在B组大鼠(0.62±0.17)显著低于A组(1.13±0.82,P<0.01)及C组(1.13±0.62,P<0.01)。尿白蛋白排泄在B组大鼠(2.18±1.98mg/d)显著高于A组(0.41±0.47mg/d,P<0.01)及C组(0.65±0.89mg/d,P<0.01)。结论氯沙坦处理能升高糖尿病大鼠肾组织的AngⅡ1型受体mRNA表达,但不改变血液及肾组织AngⅡ水平。     

血管紧张系Ⅱ受体基因敲除对跨膜钙内流的作用

目的 观察血管紧张素Ⅱ受体亚型（ＡＴ１ａ）基因敲除对跨膜钙内流的影响。方法 培养ＡＴ１ａ基因敲除及其野生型对照小鼠的主动脉血管平滑肌细胞（ＶＳＭＣ）和应用荧光倒置显微镜及钙荧光指示剂Ｆｕｒａ－２／ＡＭ动态观测ＶＳＭＣ钙离子（Ｃａ＾２＋）ｉ变化。结果 在血管紧张素Ⅱ（ＡｎｇⅡ）刺激下钙内流显著增加,ＡＴ１ａ敲除组ＶＳＭＣ钙净增值为（２０４±２２）ｎｍｏｌ／Ｌ,基础（Ｃａ＾２＋）ｉ为（１０８±９）ｎｍ     

先兆子痫患者血清血管紧张素Ⅱ 1型受体自身抗体对血管平滑肌细胞ERK1/2信号途径的激动效应

目的探讨血管紧张素Ⅱ1型受体(AT1受体)的自身激动性抗体(AT1-AAs)激动培养的大鼠血管平滑肌细胞(VSMCs)AT1受体并激活细胞外信号调节激酶1/2(ERK1/2)信号途径的能力。方法采用亲和层析法提取先兆子痫患者血清中的AT1-AAs。培养大鼠主动脉VSMCs。应用血管紧张素Ⅱ(AngⅡ)或AT1-AAs刺激培养的细胞。而后,采用免疫印迹法测定细胞中ERK1/2的表达;逆转录PCR检测细胞c-fos基因的表达;应用钙离子的荧光探针Fluo-3/AM负载培养VSMCs,应用共聚焦显微镜检测细胞荧光强度变化以反映细胞内游离钙水平的变化。结果 AT1-AAs能够发挥与血管紧张素Ⅱ类似的效应,能够激动AT1受体,促使ERK1/2的磷酸化并促进其下游的c-fos在VSMCs中的表达;并且ERK1/2的磷酸化一定程度依赖于钙离子信号。结论由于ERK1/2信号通过促进血管炎症、纤维化及血管收缩造成血管重塑,AT1-AAs可能通过该途径参与先兆子痫患者的循环障碍。     

Connective tissue growth factor is associated with the early renal hypertrophy in uninephrectomized diabetic rats

Structural remodeling in diabetic kidney ischaracterized by the early appearance ofhypertrophy in glomerular and tubular components, subsequently developing the thickness of glomerular and tubular basement membranes, and the progressive accumulation of extracellular matrix components.1 Recent studies have demonstrated that early renal hypertrophy is detrimental to the kidney in the long term and is a precursor of development of renal fibrosis.2,3 However, the exact mechanism of renal hypertrop…     

The mechanism of signal transduction during vascular smooth muscle cell proliferation induced by autoantibodies against angiotensin AT1 receptor from hypertension

Background Autoantibodies against angiotensin AT1 receptor have been discovered in patients with preeclampsia or malignant hypertension. Some studies have demonstrated that the autoantibodies are involved in the immunopathogenesis of hypertension and have an agonist effect similar to angiotensin II. Methods Autoantibodies against AT1 receptor were purified from sera of patients with primary hypertension by affinity chromatography. Proliferation of cultured rat vascular smooth muscle cells was detected by bromodeoxyuridine incorporation and activation of signalling molecules detected by Western blotting and electrophoretic mobility shift assay. Results The AT1-RAb caused a significant proliferation similar to the Ang II during first 24 hours. The levels of nuclear factor-KB （NF-KB）, phosphorylated JAK2., phosphorylated STAT1 （pSTAT1） and phosphorylated STAT3 （pSTAT3） molecules were increased in response to the autoantibodies. In contrast, the activations of NF-KB and JAK-STAT were blocked by Iosartan, pyrrolidinedithiocarbamate （a specific inhibitor of NF-KB） and AG490 （a specific inhibitor of the JAK2. tyrosine kinase）. The expressions of NF-KB, pSTAT1 and pSTAT3 reached peak levels at different times. Moreover, the relative densities of electrophoretic bands showed that activation of pSTAT3 was more significant than STAT1 induced by AT1 -RAb. Conclusions These results suggest that the autoantibodies against AT1 receptor have an agonist effect similar to Ang II in proliferation of VSMCs and the NF-KB and JAK-STAT proteins play essential roles. The effect is different from Angll in that STAT3 is the main downstream activating molecule in JAK-STAT signalling pathway.     

血管紧张素Ⅱ及其受体拮抗剂对肝星状细胞Ⅰ型胶原合成的影响

目的观察血管紧张素Ⅱ(AngⅡ)及其受体拮抗剂(AT1RA)对体外培养的肝星状细胞Ⅰ型胶原蛋白合成及其mRNA表达的影响。方法采用HSC-T6肝星状细胞系作为活化的肝星状细胞的研究模型。将培养的肝星状细胞分为对照组、AngⅡ组、AT1RA组和AngⅡ+AT1RA组。采用ELISA法检测细胞培养上清液中Ⅰ型胶原蛋白的含量。RT-PCR法检测肝星状细胞中Ⅰ型胶原mRNA的表达。结果细胞培养上清液中Ⅰ型胶原蛋白含量及肝星状细胞Ⅰ型胶原mRNA的表达水平,AngⅡ组均高于对照组,差异有统计学意义(P<0.05),AT1RA组与AngⅡ+AT1RA组均低于对照组,差异有统计学意义(P<0.05)。结论AngⅡ能够促进肝星状细胞Ⅰ型胶原蛋白的合成及其mRNA的表达,而AT1RA能够明显抑制这一作用。     

siR N A 干扰 A T1 R 基因调控链脲佐菌素诱导NIT －1细胞凋亡的实验研究

目的：用siRNA干扰技术沉默小鼠胰岛素瘤NIT－1细胞血管紧张素Ⅱ1型受体（ AT1R）基因,探讨其对链脲佐菌素（STZ）诱导的胰岛素瘤细胞凋亡的影响。方法针对小鼠AT1R基因,设计并合成3对siRNA序列,脂质体法转染至NIT－1细胞,荧光显微镜观察荧光强度检测转染效率,Real－time PCR检测AT1R mRNA表达量判断不同干扰序列及干扰时间的基因沉默效果;分4组：空白组不予任何干预,STZ组予5 mmoL／L STZ干预30 min,si－AT1R组予40 nmol／L si－AT1R转染24 h,si－AT1R＋STZ组予40 nmoL／L si－AT1R转染24 h后5 mmoL／L STZ干预30 min;Real－time PCR检测Caspase－3 mRNA表达量,Hoechst33342染色荧光显微镜和Annex-in V－FITC／PI流式细胞术检测细胞凋亡率。结果40 nmol／L siRNA转染的荧光强度最强,转染后AT1R mRNA表达量明显下降,si－AT1R－2转染24 h的沉默效果最佳（92.20％）;Caspase－3 mRNA表达量：STZ组与空白组比增加了2.37倍（P＜0.05）,si－AT1R＋STZ组与STZ组比减少了11.28％,但差异无统计学意义;细胞凋亡率：STZ组与空白组比增加了3.27倍（P＜0.05）,si－AT1R＋STZ组与STZ组比减少了26.82％（P＜0.05）。结论本研究建立了稳定的胰岛细胞AT1R基因沉默模型;RNA干扰沉默胰岛细胞AT1R基因可通过下调Caspase－3 mRNA表达量降低STZ诱导的细胞凋亡率,提示AT1R介导了STZ诱导的胰岛细胞凋亡过程。     

Effect of valsartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats

Background Many studies have suggested that angiotensin Ⅱ （Ang Ⅱ） and its receptors may be involved in the development of asthma. However, the expression of angiotensin Ⅱ receptors （AGTR） is not clear in the lung tissue of chronic asthmatics. This study was designed to determine the relationship between airway remodeling, dysfunction and the expression of AGTRs in a rat model of asthma. Methods Rats were sensitized with ovalbumin （OVA） for 2 weeks. Sixty minutes before an inhalation challenge, the rats were pretreated either with valsartan （15, 30, 50 mg.kg-1.d-1） or saline intragastrically. Then the rats received an OVA challenge for 30 alternative days. Acetylcholine （Ach）-induced bronchoconstriction was measured after the final antigen challenge. White cell counts in bronchoalveolar lavage fluid （BALF） and morphological changes in the airways were then assessed. The levels of transforming growth factor-beta 1 （TGF-β1） and platelet-derived growth factor （PDGF） in BALF were detected by ELISA. The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting. Results AGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls. The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness （mainly in small airways） in lungs of chronic antigen-exposed rats were positively correlated. Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats. However, AGTR2 mRNA and protein levels in the OVA-challenged rats and high-dose valsartan-treated rats （50 mg.kg-1.d-1） were also increased. Valsartan significantly decreased inflammatory cell accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats. Valsartan also decreased allergen-induced structural changes in rat airway （including total airway wall thickness and smooth muscle area） and the levels of TGF-β1 and PDGF in BALE Conclusions AGTR     

Effect of vaisartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats

Background Many studies have suggested that angiotensin II (Ang II) and its receptors may be involved in the development of asthma.However,the expression of angiotensin II receptors (AGTR) is not clear in the lung tissue of chronic asthmatics.This study was designed to determine the relationship between airway remodeling,dysfunction and the expression of AGTRs in a rat model of asthma.Methods Rats were sensitized with ovalbumin (OVA) for 2 weeks.Sixty minutes before an inhalation challenge,the rats challenge for 30 alternative days.Acetylcholine (Ach)-induced bronchoconstriction was measured after the final antigen challenge.White cell counts in bronchoalveolar lavage fluid (BALF) and morphological changes in the airways were then assessed.The levels of transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor (PDGF) in BALF were detected by ELISA.The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting.Results AGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls.The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness (mainly in small airways) in lungs of chronic antigen-exposed rats were positively correlated.Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats.However,AGTR2 mRNA and protein levels in the OVA-challenged rats and accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats.Valsartan also decreased allergen-induced structural changes in rat airway (including total airway wall thickness and smooth muscle area) and the levels of TGF-β1 and PDGF in BALF.Conclusions AGTR1 expression is potentially associated with airway remodeling and dysfunction in asthma.Ang II and AGTR1 may participate in airway inflammation and airway remodeling of chronic antigen-exposed rats.Valsartan,a AGTR1 antagonist,could inhibit AGTR1 expression and partially inhibits structural airway changes as well as airway inflammation in chronic OVA-exposed rats.     

血管紧张素Ⅱ2型受体基因缺失抑制诱导的成纤维细胞凋亡

目的探讨血管紧张素Ⅱ（ＡｎｇⅡ）２型受体（ＡＴ２）基因表达与成纤维细胞凋亡的关系。方法分别从正常（ＡＴ２＋／＋）和ＡＴ２受体基因缺失（ＡＴ２／）胎鼠培养皮肤成纤维细胞,经ＡｎｇⅡ诱导后,采用ＲＴＰＣＲ检测成纤维细胞ＡｎｇⅡ的ＡＴ１和ＡＴ２受体ｍＲＮＡ表达,分别用基因组ＤＮＡ电泳、ＴＵＮＥＬ染色和流式细胞仪等定性和定量方法检测细胞的凋亡改变。结果经１０８、１０７、１０６和１０５ｍｏｌ／Ｌ浓度的ＡｎｇⅡ刺激４８小时,成纤维细胞的ＡＴ１和ＡＴ２受体基因表达均有显著增强,并与浓度呈正相关。经１０６和１０５ｍｏｌ／Ｌ浓度的ＡｎｇⅡ诱导７２小时,ＡＴ２＋／＋成纤维细胞出现了明显的标志着细胞凋亡的基因组ＤＮＡ片段化,凋亡细胞分别是（１２３±２７）％和（２１７±６７）％,而ＡＴ２／成纤维细胞则未出现明显的细胞凋亡改变。结论ＡＴ２受体基因缺失后,抑制了ＡｎｇⅡ介导的成纤维细胞凋亡,为进一步揭示ＡｎｇⅡ的生理和病理作用提供了实验依据     

脉冲电场介导AT2R基因在血管局部表达及其对血管新生内膜的影响

目的研究脉冲电场对血管紧张素2型受体(AT2R)基因在血管局部表达的作用,探讨AT2R基因在体转染对大鼠颈动脉球囊损伤后新生内膜增生的作用。方法大鼠颈动脉球囊损伤后,用脉冲电穿孔法介导AT2R cDNA真核表达质粒或空质粒载体在动脉局部表达,于术后3、7 d和21 d用免疫组织化学、HE染色等方法,进行AT2R在颈动脉壁中表达的变化及定量组织形态学分析。结果免疫组织化学染色结果显示:脉冲电场介导AT2R cDNA真核表达质粒表达后,3 d时可见内膜、中膜、外膜大量AT2R的棕色阳性着色,7 d时可见少量棕色阳性着色,21 d棕色阳性着色几乎消失,未转染组及空质粒转染组未见AT2R的棕色阳性着色,表明脉冲电穿孔能有效导入AT2R基因,并在动脉壁获得稳定表达。在21 d时,AT2R cDNA真核表达质粒组的内膜面积与中膜面积比显著低于未转染组和空质粒载体组[分别为(0.76±0.08)、(1.39±0.08)、(1.32±0.10),P<0.01],空质粒转染组和未转染组间无统计学差异(P>0.01)。结论脉冲电穿孔可介导AT2R基因在血管局部有效表达,AT2R在体转染可抑制球囊损伤后大鼠颈动脉平滑肌细胞增殖和新生内膜增生。