非诺贝特促进人内皮细胞内皮一氧化氮合酶复偶联的作用研究

目的探讨非诺贝特能否对脂多糖（LPS）诱导的血管内皮一氧化氮合酶（eNOS）脱偶联发挥保护作用。方法体外培养人脐静脉内皮细胞（HUVECs）,用非诺贝特预处理HUVECs 2 h,再与LPS共孵育24 h,采用高效液相色谱法检测细胞四氢生物蝶呤（BH4）的表达水平,ELISA检测细胞eNOS表达水平和细胞上清一氧化氮（NO）浓度,利用Confocal方法检测细胞内活性氧（ROS）产生水平。结果与对照组比较,单纯LPS刺激组内皮细胞BH4表达水平降低,伴有eNOS表达下调和NO水平降低,而内皮细胞内ROS产生增加（P均〈0.05）。与单纯LPS刺激组比较,非诺贝特预处理组内皮细胞BH4表达水平升高,同时伴有eNOS表达上调和NO水平增加,而内皮细胞内ROS产生降低（P均〈0.05）。结论非诺贝特通过上调BH4水平,对LPS诱导的血管内皮细胞eNOS脱偶联有逆转作用,这可能是其发挥血管内皮保护作用的机制之一。     

罗格列酮对2型糖尿病大鼠主动脉内皮依赖性血管舒张功能的影响

目的观察2型糖尿病（T2DM）大鼠胸主动脉内皮依赖性血管舒张功能和一氧化氮（NO）、一氧化氮合酶（eNOS）的变化及罗格列酮（RSG）治疗对其内皮功能的影响。方法SD大鼠经高糖高脂喂养6周后予小剂量链脲佐菌素腹腔注射建立T2DM大鼠模型，糖尿病大鼠又分为对照（DM）组和RSG治疗组，RSG组用RSG干预8周，另选正常大鼠为正常对照（NC）组。实验终止时用正常葡萄糖高胰岛素钳夹技术的葡萄糖输注率（GIR）评价胰岛素抵抗，观察大鼠离体主动脉内皮依赖性血管舒张反应和主动脉NO、eNOS的变化。结果T2DM大鼠GIR、胸主动脉内皮依赖性血管舒张反应、主动脉NO含量及eNOS阳性表达较NC组显著降低（P〈0、01），RSG治疗后上述指标均显著升高（P〈0．05）。结论T2DM大鼠存在内皮依赖性血管舒张功能紊乱，RSG治疗可改善内皮功能，增强NO水平和eNOS的活性。     

氯沙坦对高血压患者血清一氧化氮、内皮素-1和血管内皮功能的影响

目的 探讨氯沙坦对高血压患者血清一氧化氮（NO）、内皮素-1（ET-1）和血管内皮功能的影响.方法 入选108例首诊轻、中度高血压患者,给予氯沙坦50～100 mg,qd,共12周;另人选同期健康体检者为正常对照组（对照组100例）.观察高血压患者治疗前后血流介导的肱动脉内皮依赖性血管舒张功能（FMD）、ET-1和NO的变化.结果 随访12周后,与治疗前比较,高血压患者的血压下降,FMD提高,NO上升,ET-1降低（均P〈0.05）.多元线性逐步回归显示,校正年龄、血压、血脂、血糖等因素后,ET-1和NO是FMD的影响因素（均P〈0.05）.结论 氯沙坦改善高血压患者血管内皮功能可能与减少内皮素分泌,增加一氧化氮水平有关.     

冠状动脉造影中血压升高患者冠状动脉狭窄与血管内皮功能及炎症因子的相关性研究

目的探讨冠状动脉造影中血压升高的非高血压患者的冠状动脉狭窄与血管内皮功能及炎症因子的相关性。方法选择1141例疑诊冠心病的非高血压患者,所有患者均行冠状动脉造影检查,其中将冠状动脉造影过程中监测收缩压升高≥30 mm Hg（1 mm Hg=0.133 kPa）和（或）舒张压升高≥15 mm Hg的患者分为观察组,反之为对照组,测定两组患者一氧化氮（NO）、肱动脉介导的血管内皮功能（FMD）及超敏C反应蛋白（hs-CRP）、可溶性白细胞分化抗原配体（sCD40L）水平。观察术中血压升高者其冠状动脉狭窄与血管内皮功能及炎症因子的关系。结果两组术前及术后血压比较,差异均无统计学意义。冠状动脉造影结果显示,对照组以正常和狭窄〈50%为主,而观察组则以狭窄〈50%和狭窄≥50%为主,观察组冠状动脉狭窄≥50%者比例显著高于对照组（χ2=79.87,P〈0.05）,而对照组冠状动脉造影正常者比例显著高于观察组（χ2=79.87,P〈0.05）。观察组血浆NO水平（P=0.004）及代表血管内皮依赖性舒张功能的FMD（P=0.023）显著低于对照组;而代表炎症反应的hs-CRP（P=0.036）及sCD40L（P=0.015）显著高于对照组。结论冠状动脉造影术中血压升高的非高血压患者已存在冠状动脉狭窄、血管内皮功能障碍及血浆炎症因子升高。     

高尿酸血症大鼠血尿酸与血管内皮功能相关性的研究

目的：探讨高尿酸大鼠血尿酸与血管内皮功能的关系。方法：雄性SD大鼠36只,随机均分为正常对照组、模型组和别嘌醇治疗组。使用高酵母膏饲料联合氧嗪酸钾腹腔注射6周诱导大鼠高尿酸模型。别嘌醇治疗组除给予造模剂外同时以别嘌醇灌胃6周。定期测量大鼠收缩压。6周后处死大鼠,检测各组血清尿酸（SUA）、一氧化氮（NO）、内皮素-1（ET-1）、收缩压（SBP）等的变化,用免疫组化法检测大鼠主动脉内膜层内皮型一氧化氮合酶（eNOS）的表达量。结果：与正常对照组相比,模型组大鼠SUA水平[（45.1±5.6）μmol/L∶（216.0±6.2）μmol/L]显著升高（P〈0.001）,ET-1[（85.4±8.7）μg/L∶（163.1±7.2）μg/L]、SBP[（115.7±4.1）mm-Hg∶（156.0±3.8）mmHg]显著升高,血NO[（24.1±2.0）μmol/L∶（17.2±3.4）μmol/L]及主动脉内膜层eNOS[（48.3±4.2）∶（38.3±4.5）]表达量显著降低（P均〈0.05）;与模型组比较,别嘌醇组SUA[（44.8±4.3）μmol/L]、ET-1[（92.8±5.0）μg/L]、SBP[（119.2±4.3）mmHg]水平显著降低,血NO[（22.1±2.2）μmol/L]和主动脉内膜eNOS的表达量（46.1±4.2）明显升高（P均〈0.05）,别嘌醇组与正常对照组比较上述指标无明显差异（P〉0.05）。SUA与SBP、ET-1呈正相关（r=0.98、0.98,P均〈0.001）,与NO呈负相关（-0.70,P〈0.001）。结论：高尿酸血症与大鼠血管内皮功能紊乱密切相关。血一氧化氮的降低和内皮素-1的升高可能是发生高血压的重要原因之一。别嘌醇具有保护血管内皮功能的作用。     

麝香保心丸对高同型半胱氨酸血症大鼠内皮功能的影响

目的在大鼠高同型半胱氨酸血症(HHcy)模型上,探讨麝香保心丸对血管内皮功能的影响。方法将24只雄性SD大鼠随机分为正常对照组、HHcy组及HHcy+麝香保心丸组,每组8只。采用酶联免疫吸附法(ELISA)检测血浆同型半胱氨酸(Hcy)水平,采用硝酸还原酶法检测大鼠血浆一氧化氮(NO)含量,采用免疫组织化学法检测主动脉一氧化氮合成酶(eNOS)表达。结果 L-蛋氨酸灌胃能够诱导大鼠HHcy模型,使血浆NO含量减少,血管内皮eNOS表达同步下调;采用麝香保心丸干预后,内皮功能有所改善。结论麝香保心丸可改善HHcy引起的内皮功能障碍。     

肺血栓栓塞患者血浆ET-1、NO水平与血管内皮依赖性舒张功能的关系

目的探讨肺血栓栓塞症（PTE）患者溶栓和（或）抗凝治疗前后血浆内皮素1（ET-1）、一氧化氮（NO）及血管内皮依赖性舒张功能（EDD）的变化及其临床意义。方法PTE患者82例,分为溶栓组及抗凝组,并选取健康者20例为对照组。应用放射免疫方法检测ET-1,硝酸还原酶法测定血浆NO浓度,同时应用超声测量肱动脉EDD,并比较溶栓和抗凝治疗前及治疗1周时各项指标的变化。结果与对照组相比,溶栓及抗凝治疗组NO、ET-1、EDD差异有统计学意义（P均〈0.01）。两组PTE患者治疗1周后NO、EDD较治疗前明显升高、ET-1明显下降,差异亦有统计学意义（P均〈0.01）。相关分析显示,PTE患者ET与NO、EDD呈负相关（r=-0.508、-0.533,P均〈0.01）;NO与EDD呈正相关（r=0.685,P〈0.01）。结论肺栓塞患者存在血管内皮功能损伤,EDD可以作为评价肺栓塞患者内皮功能损伤的指标。     

内皮型一氧化氮合酶基因突变与心血管疾病

内皮衍生的一氧化氮（NO）具有重要的生理功能，它由内皮型一氧化氮合酶（eNOS)合成。NO和动脉粥样硬化的形成和血压的调节有关。NO还可能参与冠状动脉痉挛的发生。本文就eNOS基因的突变与心血管疾病的关系进行综述。     

1型糖尿病患者血浆microRNA-126 变化与内皮功能的相关性

目的 探讨1型糖尿病患者血浆microRNA-126表达水平的变化及其临床意义，并分析microRNA-126与内皮功能的关系。方法 采用实时荧光定量聚合酶链反应检测47例1型糖尿病患者及50例健康对照组人群血浆microRNA-126的表达水平，酶联免疫吸附法检测人内皮型一氧化氮合酶（eNOS）含量，分析血浆microRNA-126表达水平与人内皮型一氧化氮合酶含量的相关性。结果 与健康对照组相比，1型糖尿病组血浆microRNA-126表达水平明显下降（P<0.05），人内皮型一氧化氮合酶含量也明显下降（P<0.05）。相关分析显示血浆microRNA-126表达水平与人内皮型一氧化氮合酶含量呈明显正相关（P<0.05）。结论 1型糖尿病患者血浆microRNA-126水平呈低表达，而糖尿病患者常伴有内皮功能损伤，提示microRNA-126的下调可能与内皮损伤有关。microRNA-126可能通过介导内皮功能的损伤而参与1型糖尿病血管并发症的发生发展。     

冠状动脉慢血流与内皮功能损伤的相关性研究

目的通过测定冠状动脉慢血流(CSF)患者血浆中的一氧化氮(NO)和内皮素-1(ET-1)的变化,探讨CSF的发病机制与血管内皮功能损伤的关系。方法选择经冠状动脉造影(CAG)诊断为无管腔狭窄及无慢血流者85例(对照组),CAG示CSF者85例(慢血流组),以及CAG示冠状动脉有意义狭窄者85例(狭窄组)。采用校正的TIMI血流分级(CTFC)方法评价冠状动脉血流速度。分别测定3组患者血浆中NO、ET-1的水平。结果慢血流组和狭窄组血浆ET-1均高于对照组,差异有统计学意义(P<0.05);慢血流组血浆ET-1低于狭窄组,差异有统计学有意义(P<0.01)。慢血流组和狭窄组血浆NO均低于对照组,差异有统计学意义(P<0.01);慢血流组血浆NO高于狭窄组,差异有统计学意义(P<0.01)。慢血流组和狭窄组低密度脂蛋白胆固醇、血尿酸水平和吸烟比例均高于对照组,对照组高密度脂蛋白胆固醇高于慢血流组和狭窄组,差异均有统计学意义(P<0.05)。经多元Logistic回归分析表明,ET-1升高、NO降低、低密度脂蛋白胆固醇升高、高密度脂蛋白胆固醇降低、血尿酸升高以及吸烟为CSF的独立危险因素。结论血尿酸和低密度脂蛋白胆固醇升高,高密度脂蛋白胆固醇降低以及吸烟可能参与CSF的病理生理发生过程,内皮功能损伤与CSF的发病机制有密切关系。     

雄激素缺乏对雄性大鼠血管内皮细胞的影响

目的:观察雄性大鼠去势后,雄激素缺乏对血管内皮细胞功能和结构的影响。方法:雄性Wistar大鼠20只随机化分为单纯去势组(10只)和假手术组(10只)。8周后,用放射免疫法测定两组大鼠血浆睾酮的浓度,取胸主动脉HE染色后,观察血管内皮细胞的形态变化;采用化学比色法测定血浆一氧化氮(NO)的水平,用ELISA法检测血清内皮素-1(ET-1)的含量。结果:与假手术组相比较,单纯去势组血浆睾酮的浓度及血浆NO的水平均显著降低,分别为[(2.47±0.53)μg/L vs.(0.28±0.07)μg/L和(33.44±8.50)μg/L vs.(21.61±10.51)μg/L,P<0.05];而血浆ET-1的含量则明显升高[(3.84±0.16)μg/L vs.(4.41±0.34)μg/L,P<0.05]。单纯去势组血管平滑肌细胞的排列不整齐,管壁厚薄欠均匀,血管内皮细胞增生。结论:雄性大鼠去势后雄激素缺乏可使大鼠血管内皮受损,释放NO减少以及ET-1增加。     

淫羊藿总黄酮对高脂血症大鼠主动脉血管内皮功能的影响

目的:探讨淫羊藿总黄酮(TFE)对喂养高脂饮食的大鼠主动脉一氧化氮(NO)及一氧化氮合酶(NOS)的影响以及抗动脉粥样硬化(AS)的可能机制。方法: 将35只SD大鼠随机分为普通饮食组（n=9）和高脂饮食组（n=26）。后者喂以高脂饮食12周后,检测空腹血脂,若已出现高脂血症说明造模成功,再随机分为模型组、小剂量［100 mg/(kg·只)］TFE组及大剂量［200 mg/(kg·只)］TFE组。16周后,检测各组血脂水平,三酰甘油(TG)用TPO-PAP法检测,总胆固醇(TC)用CHOD-PAP法检测,低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)用选择性沉淀法检测。主动脉NO水平通过硝酸还原法检测、用精氨酸催化法检测主动脉总NOS(tNOS)、诱导型NOS(iNOS)及构成型NOS(cNOS)（等于tNOS与iNOS之差）的水平。结果: 以高脂饮食喂养12周后,高脂饮食组TG、TC及LDL的水平明显升高(P<0.01)。给药4周后,与模型组比较,TFE组大鼠的血脂谱能明显改善,TC和TG的水平明显降低(P<0.05,P<0.01)。模型组主动脉NO和cNOS的水平显著下降(P<0.05,P<0.01),TFE组主动脉NO和cNOS的水平显著提高(P<0.05,P<0.01)。结论: TFE能改善血脂及提高主动脉NO、cNOS的水平。     

Globular adiponectin upregulates nitric oxide production in vascular endothelial cells

Aims/hypothesis Adiponectin, also called ACRP30, is a novel adipose tissue-specific protein that has been shown to improve insulin sensitivity and to exert anti-atherogenic effects. It is known that knockout mice lacking endothelial NO synthase (eNOS) develop hypertension, insulin resistance, hyperlipidaemia, and show augmented ischaemia-reperfusion damage. Thus, we examined whether globular adiponectin activates eNOS to produce NO.Methods To analyze NO production in bovine aortic endothelial cells (BAE), NOx (nitrite and nitrate) was measured in the medium with an automated NO detector/high-performance liquid chromatography system. eNOS activation was assessed by phosphorylation of the enzyme and its activity was evaluated by citrulline synthesis in human umbilical vein endothelial cells (HUVEC). eNOS mRNA and protein expressions in HUVEC were evaluated by Realtime PCR and Western blot analysis.Results Gobular adiponectin increased NO production in BAE. It also caused eNOS phosphorylation and potentiated eNOS activity in HUVEC. In addition, globular adiponectin up-regulated the eNOS gene to increase protein expression in HUVEC.Conclusion/interpretation Globular adiponectin increases NO production through two mechanisms, namely, by activation of eNOS enzyme activity and via an increase in eNOS expression. Activation and up-regulation of eNOS could explain some of the observed vasoprotective properties of globular adiponectin, as well as its beneficial effects on the cardiovascular system.Abbreviations NO nitric oxide - eNOS endothelial NO synthase - BAE bovine aortic endothelial cells - HUVEC human umbilical vein endothelial cells - ACRP30 adipocyte complement-related protein of 30 kDa - GAPDH glyceraldehyde-3-phosphate dehydrogenase     

Genetic variants of endothelial nitric oxide synthase in patients with primary biliary cirrhosis: association with disease severity

BACKGROUND AND AIMS: Primary biliary cirrhosis (PBC) presents a wide spectrum of clinical manifestations. In experimental models of liver cirrhosis and cholestasis it has been suggested that altered nitric oxide production is involved in liver injury and portal hypertension development. The present study investigated endothelial nitric oxide synthase (eNOS) genetic polymorphisms (894G/T, -786T/C) in patients with PBC and in controls to verify whether disease susceptibility and progression are associated with a particular genotype. METHODS: Genomic DNA from 109 Italian PBC patients (65 with advanced disease, i.e. liver transplantation or histological stage III-IV) was obtained and polymorphisms determined by fluorescent probe analysis. Healthy subjects (n = 242) were used as a control group. RESULTS: The allelic frequencies of both polymorphisms did not differ significantly between PBC patients and controls. When the association between genotypes and disease severity was addressed, both the 894T and the -786T alleles were more frequently found in the 22 patients with progressing disease (894T, frequency 0.455 compared with 0.240; P = 0.032; -786T, frequency 0.682 compared with 0.460; P = 0.038). Patients with 894TT presented higher Mayo score values (6.1 +/- 1.2 compared with 5.4 +/- 1.3 in 894G/G patients; P = 0.030) but similar age and disease duration values. CONCLUSIONS: The authors suggest that genetic variants of eNOS are not associated with susceptibility to PBC, although the genotypes may lead to differences in disease severity and progression.     

一氧化氮对自发性高血压大鼠血管内皮功能的作用

目的　探讨自发性高血压大鼠 (SHR)内皮舒张功能不全的发生机制。方法　采用体外灌注的方法测定大鼠胸主动脉环对不同浓度乙酰胆碱的舒张反应变化 ,并测定血清中NO-3浓度和动脉组织中环鸟苷酸水平。结果　与魏 凯二氏大鼠 (WKY)比较 ,SHR胸主动脉环对乙酰胆碱的舒张反应明显减弱。左旋硝基精氨酸 (L NNA)可明显抑制大鼠胸主动脉环对乙酰胆碱的舒张反应 ,但并不能消除SHR和WKY对乙酰胆碱舒张反应之间的差异。与WKY比较 ,SHR血中NO-3水平明显降低 (P<0 .0 1) ,动脉组织中环鸟苷酸含量降低 (P<0 .0 1)。结论　SHR内皮依赖的血管舒张功能减低 ;一氧化氮 (NO)的生成或释放不足可能直接参与了SHR血管内皮依赖的舒张功能不全。     

Nitric oxide production in PCD: possible evidence for differential nitric oxide synthase function

Primary cilliary dyskinesia (PCD) is characterized by decreased levels of fractional exhaled nitric oxide (FeNO), thought to reflect low activity of airway inducible nitric oxide synthase (iNOS) levels. Alveolar NO (Calv) concentration and bronchial NO (JNO) flux can be calculated from FeNO measured at multiple exhalation flow rates. We hypothesised that whereas bronchial NO would be reduced in PCD due to reduced iNOS function, alveolar NO would reflect endothelial NOS (eNOS) function and be normal. We recorded the medical history; measured FeNO at multiple flow rates (50, 100, 200, 260 ml/sec); and performed spirometry in 24 children (aged 8-16 years). FeNO50 of the PCD children was significantly lower than normal mean (+/-SD) 8.1 +/- 1.3 ppb versus 12.5 +/- 1.6 ppb, P = 0.033. The mean +/- SD values of PCD (n = 24) and normal (n = 20) subjects were respectively: JNO: 383.5 +/- 307.9 versus 650.1 +/- 489 pl/s, P = 0.033, Calv: 1.60 +/- 0.78 versus 1.60 +/- 0.75 ppb, P = NS. We show that Calv is normal in PCD, demonstrating that there is no generalized disorder of NO handling in this condition. This differs from a previous report. Furthermore, we speculate that these data may provide supportive evidence that variable flow NO measurements can assess the relative activity of iNOS and eNOS.     

Low-density lipoprotein size,high-density lipoprotein concentration,and endothelial dysfunction in non-insulin-dependent diabetes

We examined endothelial function (nitric-oxide mediated) in 29 men with diet-treated non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) and 18 male age-matched controls. Forearm blood flow was measured by venous occlusive plethysmography during intra-arterial administration of acetylcholine (ACh, 7.5 and 15 μg min⁻¹) and sodium nitroprusside (SNP, 3 and 10 μg min⁻¹). LDL particle size was estimated by non-denaturing gel electrophoresis. Serum lipids, blood pressure, and glycated haemoglobin were also measured. LDL particle size was smaller (p = 0.048) in the diabetic patients than controls. In the diabetic patients, LDL particle size was a significant positive predictor (p = 0.01) of the area under the dose–response curve for ACh, after adjusting for age, HbA_1c, systolic BP, and cholesterol (R² 0.20). In stepwise regression including serum lipid and lipoprotein concentrations and LDL particle size, decreased HDL cholesterol was the best predictor of an impaired vasodilatory response to ACh. Vasodilatory responses to sodium nitroprusside were not significantly correlated with LDL particle size or serum lipid and lipoprotein concentrations. We conclude that in men with NIDDM, small, dense LDL particle size is associated with abnormal endogenous release of nitric oxide. The contribution of small, dense LDL particles to the development of endothelial dysfunction and early diabetic vasculopathy may not, however, be as great as decreased HDL cholesterol. © 1997 John Wiley & Sons, Ltd.