一氧化氮合酶与肝炎病毒关系研究进展

一氧化氮 (NO)是一种半衰期极短的生物调节因子 ,是通过NO合酶 (NOS)催化L—精氨酸生成的 ,NO具有广泛的生物学功能。由于产生的部位或方式不同 ,NOS分为 3类 ,分别为I、II、III型NOS ,I型和III型NOS为机体细胞所特有的 ,而II型NOS主要存在于巨噬细胞[1] 和肝实质细胞中 ,其表达可被一些内毒素、细胞因子、微生物产物[1 4 ] 所诱导 ,因此又被称为诱导型NOS(iNOS)。目前研究认为NO具有潜在的抗病毒活性[5] ,但具体机制仍在研究之中。本文将目前关于NOS与病毒肝炎形成和抗病毒作用研究进展进行简要的回顾。一、一氧化氮合酶…     

一氧化氮一氧化氮合酶与心功能

一氧化氮是一个细胞－细胞间信息传递因子，作为第二信使和神经递质在体内起着重要而广泛的作用，它还可介导细胞免疫和细胞毒性；一氧化氮合酶作为内源性一氧化氮生成的限速酶，有三种同工酶，其在体内的分布与表达调控机制不同；生理、病理条件下，一氧化氮与心功能变化密切相关     

糖尿病心血管病变与一氧化氮及一氧化氮合酶的关系

心血管病变足2型糖尿病（T2DM）最常见的并发症之一，其发生机制与诸多因素有关，如高血糖、胰岛素抵抗导致血管内皮功能紊乱，机体氧化和抗氧化平衡失调，蛋白激酶C激活，抑制一氧化氮合酶（NOS）活性，使一氧化氮（NO）含量减少，而炎症介质介导的细胞增殖加剧，这些原因均可促进动脉粥样硬化，导致心血管疾病的发生。糖尿病患者患心血管疾病的风险性足非糖尿病患者的2～5倍。许多研究证实糖尿病患者血清中NO含量降低，并发心血病患者NO含量更低，但也有报道糖尿病早期NO含量升高，可能与发病初期由于激活的巨噬细胞合成NO增加等因素有关。糖尿病晚期NO含量下降，此时由于糖基化作用产生大量不可逆糖基化终末产物，导致NO清除加速。糖尿病心血管病变与NO及NOS间有着密切的关系。     

小鼠肺巨噬细胞一氧化氮合酶与肿瘤杀伤细胞间的关系

一氧化氮（ＮＯ）为活化的巨噬细胞的细胞毒效应分子之一。我们测定肺巨噬细胞（ＡＭ）内的诱导型一氧化氮合酶（ｉＮＯＳ）及产物ＮＯ水平,并应用特异性一氧化氮合酶（ＮＯＳ）抑制剂来观察ＡＭ对肿瘤细胞杀伤作用的影响,以探讨ＮＯＳ活性与肿瘤杀伤力之间的关系。材料...     

一氧化氮合酶和微血管生成与胃癌发展的关系

目的　研究诱导型一氧化氮合酶 (iNOS)在人胃癌组织中的表达及其与胃癌微血管形成、淋巴结转移及临床分期的关系。方法　采用免疫组化S P法检测 50例原发性胃癌组织、癌周组织及 2 0例正常胃黏膜组织中iNOS的表达 ,同时检测微血管密度 (MVD) ,以抗CD3 4标记血管内皮细胞 ,并分析其与肿瘤行为之间的关系。结果　 50例胃癌组织中iNOS阳性表达率为 70 .0 % ,MVD均值为 2 2 .0± 9 .8,显著高于癌周组织 (16.2 % ,6.1± 3 .4)和正常胃组织 (15.0 % ,5.5± 2 .6;P <0 .0 1)。按TNM分期 ,Ⅳ期胃癌组织iNOS阳性表达率为 93 .8% ,MVD为 42 .3± 3 .7,两者显著高于Ⅰ、Ⅱ、Ⅲ期 ,差异有显著性 (P <0 .0 1)。有淋巴结转移组iNOS的阳性表达率为 84.6% ,MVD均值为 2 7.4± 6.5;无淋巴结转移组iNOS阳性表达率为 54.2 % ,MVD均值为 15.3± 4.7,两组差异有显著性 (P <0 .0 5)。iNOS阳性表达组及高MVD值 (≥ 2 2 .0 )组的 3年生存率均显著低于iNOS阴性表达组及低MVD值 (<2 2 .0 )组 ,差异有显著性 (P <0 .0 5)。结论　胃癌组织中iNOS高阳性表达 ,随着iNOS阳性表达的增强 ,MVD值也增加 ,两者呈正相关。iNOS的表达及MVD与胃癌TNM分期、淋巴结转移及预后有密切关系。iNOS的表达及MVD值可作为判断胃癌预后的重要指标     

脑梗死患者血清一氧化氮和一氧化氮合酶水平与脑血管反应性的关系

目的探讨脑梗死患者血清中一氧化氮(N0)和一氧化氮合酶(NOS)水平的变化对脑血管反应性(CVR)的影响。方法采用前瞻性病例对照研究,脑梗死组为发病2周内的颈内动脉系统脑梗死患者(193例),对照组为无脑梗死的体检者(103例)。对两组分别使用Griess重氮化反应法和酶标法,进行静脉血NO产物浓度及NOS活性检测;采用经颅多普勒超声结合屏气试验获取屏气指数(BHI)以评价CVR。结果脑梗死组和对照组的BHI分别为1.0±0.4和1.4±0.5,NO产物浓度中位数分别为6.04(3.83～11.49)、6.89(4.64～12.43)μmol/L,NOS活性分别为(3.0±1.5)、(3.2±1.5)U/ml。脑梗死组BHI及NO产物浓度均低于对照组(均P<0.05),BHI与NO产物浓度呈正相关(r=0.39,P=0.000),与NOS活性无相关性(r=0.168,P=0.454)。两组NOS活性差异无统计学意义(P=0.517)。结论脑梗死患者的CVR降低,与NO含量减少有一定相关性,但尚不能确定CVR与NOS活性的关系。NO可能是参与调节CVR的因素之一。     

一氧化氮及一氧化氮合酶与骨质疏松

一氧化氮（NO）是体内重要的信号分子和效应分子，一氧化氮合酶（NOS）是NO合成的限速酶。在骨组织中，由骨细胞生产的NO可通过自分泌或旁分泌或旁分泌方式影响骨重建。病理条件下，NO异常分泌可使骨形成与骨吸收失平衡，这与骨质疏松的发病密切相关，因此药物调节NO量成为探索治疗骨质疏松症的新途径之一。     

一氧化氮及一氧化氮合酶与肝病

一氧化氮（ＮＯ）是普遍存在于脊椎动物各种细胞中的一种生物介质，是细胞间信息传递的重要调节因子，作为第二信使和神经递质起着各种不同的功能。ＮＯ参与机体生理及病理过程，其对疾病发生及发展的影响是近年来研究的热点。现就有关ＮＯ及一氧化氮合酶（ＮＯＳ）在肝病...     

一氧化氮及一氧化氮合酶与肝癌

一氧化氮(NO)是生物体内重要的生物活性分子,具有氧化还原特性,参与一系列生理和病理过程,如血管扩张、血小板粘附与聚集、神经信号转导、机体防御反应等,同时在肿瘤的发生发展中也发挥重要作用。低浓度NO可促进肿瘤细胞增殖、促血管形成等利于肿瘤生长,高浓度时则通过干扰能量代谢、基因毒性、抑制蛋白合成、诱导凋亡等途径而具有抗肿瘤作用。随着NO与肿瘤关系研究的深入,它与肝癌的关系日益受到重视。研究发现,肝癌组织中有各种NOS的表达,NO参与肝癌的发生、发展,与肝癌的血管形成密切相关,并参与肝癌的浸润与转移。本文就近年来NO与肝癌的关系作一综述,为肝癌的发病机制和治疗提供新的切入点。     

Endothelial nitric oxide synthase polymorphism, nitric oxide production, salt sensitivity and cardiovascular risk factors in Hispanics

Mutations in the endothelial nitric oxide synthase (eNOS) gene may be associated with abnormal nitric oxide (NO) production and cardiovascular diseases. In this study, we investigated the prevalence of two eNOS polymorphisms, the Glu298Asp variant on exon 7, and the 4a/b variable number of tandem repeats (VNTR) on intron 4, and their association with blood pressure (BP), NO production, salt sensitivity and cardiovascular risk factors in healthy Venezuelans. The prevalence of both polymorphisms in Venezuelans was comparable to that described for Caucasians, but significantly different from that known for African-Americans and Japanese. The 4a/b genotype was associated with reduced levels of NO metabolites (25% decrease), larger BP lowering in response to salt restriction (9.0 vs 4.8 mmHg, P<0.05), greater prevalence of salt sensitivity (39% in 4a/b and 27% in 4b/b; P<0.05) and with higher LDL-cholesterol levels. The Glu298T polymorphism did not affect NO production, nor it was associated with salt sensitivity. Glu298Asp polymorphism was positively associated with higher weight, triglycerides and LDL-cholesterol. Neither polymorphism was associated with changes in fasting or postload serum glucose, BP, obesity and albuminuria. In conclusion, the prevalence of eNOS polymorphisms is strongly determined by ethnic factors. The 4a/b gene polymorphism could be a genetic susceptibility factor for the BP response to salt intake and for the genetic control of NO production. The reduced NO production in subjects with the 4a/b genotype may be responsible for the increased sensitivity of their BP to salt.     

比索洛尔对一氧化氮和内皮型一氧化氮合酶昼夜节律的影响

目的探讨比索洛尔对大鼠一氧化氮和内皮型一氧化氮合酶(eNOS)及心肌组织eNOSmRNA表达水平昼夜节律的影响。方法健康雄性SD大鼠128只,体质量250～300g,随机分为4组:7:00灌药组(早灌药组)、19:00灌药组(晚灌药组)、7:00对照组(早对照组)、19:00对照组(晚对照组),每组32只。每日早灌药组与晚灌药组均给予比索洛尔3mg/kg灌服,两对照组分别于7:00与19:00给予相同剂量的安慰剂灌服。4周后,分别于同日内不同时间点(2:00,8:00,14:00,20:00)处死4大组大鼠中各8只大鼠,留取血清和心肌组织。分别采用比色法和硝酸还原法、逆转录多聚酶链反应法检测血和心肌组织中eNOS、一氧化氮的含量或活性以及eNOSmRNA的表达水平。结果两灌药组之间、两对照组之间血清及组织一氧化氮、eNOS含量或表达差异无统计学意义(均P>0.05),但灌药组和对照组之间血清及组织一氧化氮、eNOS含量或表达差异有统计学意义(均P<0.05),灌药组的一氧化氮、eNOS含量明显升高,eNOSmRNA的表达增强(P<0.05)。各组血清及组织一氧化氮、eNOS含量或表达均存在昼夜节律,灌药组部分节律振幅、峰值改变。灌药组和对照组各组的组织eNOSmRNA存在典型昼夜节律,节律振幅无差异。早、晚灌服比索洛尔对于一氧化氮、eNOS以及eNOSmRNA昼夜节律的影响有所不同。结论比索洛尔升高血清及组织一氧化氮、eNOS的含量,促进组织eNOSmRNA的表达。比索洛尔可对内皮源性血管活性物质的时间生物学特征产生影响,用药时间不同,对各参数的影响亦有所不同。     

阿托伐他汀对冠心病患者血清一氧化氮及一氧化氮合酶含量的影响

目的　观察阿托伐他汀对冠心病患者血清一氧化氮 (NO)及一氧化氮合酶 (NOS)含量水平的影响。方法　对用阿托伐他汀治疗的 79例冠心病患者依据是否合并高胆固醇血症分为两组 ,对其治疗前后血清 NO及 NOS含量水平进行对比分析。结果　不论是否合并高胆固醇血症的冠心病 ,阿托伐他汀均可升高其血清 NO及 NOS水平。结论　阿托伐他汀可通过调脂治疗抑制脂质的过氧化反应 ,保护血管内皮功能 ,但其保护内皮功能的作用不受患者是否存在高脂血症的影响 ,改善内皮功能 ,对冠心病的防治具有重要意义。     

梅毒患者血清一氧化氮和一氧化氮合酶水平测定

目的　检测梅毒螺旋体感染者血清中一氧化氮 (NO)和一氧化氮合酶 (NOS)的水平。方法　用分光光度法测定血清中NO水平和NOS活性 ,血清中NO3 和NO2 总量代表体内NO水平 ,NOS催化L 精氨酸和氧的反应生成NO的多少代表血清NOS活性。结果　梅毒患者NO浓度为 115± 36 3nmol/L ,NOS活性为 35 8± 7 3U/ml,二者均远远高于正常对照组。结论　梅毒螺旋体的感染引起患者体内NO水平和NOS活性升高 ,NO在梅毒感染中可能发挥重要的作用。     

Inducible nitric oxide synthase and atherosclerosis

Nitric oxide (NO) synthase induction in vascular smooth muscle cells may play a role in local vascular injury associated with atherosclerosis or postangioplasty restenosis by inhibiting smooth muscle cell proliferation and contraction, as well as by preventing leukocyte and platelet adhesion. The expression of inducible NO synthase is increased in balloon-injured arteries of experimental animals or in human atherosclerotic lesions. Replacement therapy with NO donors or NO synthase gene transfer may improve the clinical course of atherosclerosis or restenosis.     

Expression of endothelial nitric oxide synthase and inducible nitric oxide synthase in synovium of rheumatoid arthritis]

OBJECTIVES: To examine the localization and distribution of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS), which participate in nitric oxide (NO) production, in synovium of rheumatoid arthritis (RA). MATERIALS AND METHODS: Immunohistochemical analysis for eNOS and iNOS in synovial tissues obtained from 10 patients with RA who were underwent total knee replacement. Synovial tissues of osteoarthritis (OA) were used as control. The percentage of cells that were positive for eNOS and iNOS was estimated in five hundred endothelial cells, synovial lining cells and interstitial cells, respectively. And mRNA expression of NOS was confirmed by in situ hybridization. In addition, to test NO production, nitration of tyrosines was assessed by immunohistochemistry. RESULTS: Not only endothelial cells but also synovial lining cells and interstitial cells exhibited immune-reactive both eNOS and iNOS. Cells which were seemed immune-reactive eNOS and iNOS expressed nitrotyrosin. By in situ hybridization, we detected mRNA expression for eNOS and iNOS. CONCLUSIONS: Endothelial cells, synovial lining cells and interstitial cells expressed both eNOS and iNOS with high frequency in RA synovium compared with OA synovium. It seemed to correlate with NO production. These results suggest that expression of iNOS may be involved in the induction of arthritis and eNOS may be participated in augmentation of inflammation in RA.     

Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

AIM: To investigate the dynamic change and role of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis (NEC) is associated with the levels of nitric oxide synthase (NOS) in the mucosa of the affected intestine tissue. METHODS: Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide (IPS). Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined. RESULTS: The LPS-injected pups showed a significant increase in injury scores versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury. CONCLUSION: nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.     

Novel features of nitric oxide,endothelial nitric oxide synthase,and atherosclerosis

There is a complex pathophysiologic scenario involving nitric oxide (NO), endothelial nitric oxide synthase (_eNOS), and the development of atherosclerosis and unstable atheroma. Endothelial damage induced by atherosclerosis leads to the reduction in bioactivity of _eNOS with subsequent impaired release of NO. An important mechanism is local enhanced degradation of NO by increased generation of reactive oxygen species and other free radicals, with subsequent cascade of oxidationsensitive mechanisms in the arterial wall. Novel molecular approaches have resulted in the development of new strains of mice lacking _eNOS. These experimental models will help to understand how to implement NO-based therapies against atherosclerosis. L-arginine, the precursor of NO, has demonstrated beneficial effects in atherosclerosis and disturbed shear stress. The target or goal for new drugs should be the complete restoration of NOmediated signaling pathways in atherosclerotic arteries.