中国老年人心肌梗死遗传易感性与血管内皮型一氧化氮合酶基因Glu298Asp多态性的关系

背景诸多研究认为血管内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)基因多态性与心、脑、肾疾病存在相关性,但eNOS-Glu298Asp与中国老年人心肌梗死的关系是否相关尚不明确.设计以诊断为依据的病例对照研究.目的探讨老年人血管内皮型一氧化氮合酶基因Glu298Asp多态性的分布,及其与老年心肌梗死的关系.地点、对象和方法37例老年心肌梗死患者为病例组,均为南京医科大学第一附属医院门诊及住院患者,其中20例既往无高血压史者为病例亚组;172例本院体检中心复检者(对照组),其中92例既往无高血压者为对照亚组,分别检测病例组和对照组的身高、体质量、空腹血脂等指标,采用聚合酶链反应(polymerase chain reaction,PCR)和限制性片断长度多态性(restrictionfragmentlength polymorphism,RFLP)检测eNOS基因Glu298Asp多态性.主要观察指标4组老年人eNOS基因Glu298Asp多态性及298Asp等位基因频率.结果病例组Glu/Asp基因型高于对照组(32.43%和18.02%),两组eNOS基因Glu298Asp多态性构成差异有显著性意义(x2=3.87,P<0.05).病例亚组Glu/Asp基因型(35.00%)高于对照亚组(10.87%),差异有显著性意义(x2=7.43,P<0.01).病例组298Asp等位基因频率高于对照组,差异无显著性意义(P>0.05).病例亚组298Asp等位基因频率高于对照亚组,差异有显著性意义(x2=6.82,P<0.01).结论eNOS基因Glu298Asp多态性在中国老年人群中存在,Glu/Asp基因型和298Asp等位基因可能是中国老年人心肌梗死的遗传易感指标.     

中国老年人心肌梗死遗传易感性与血管内皮型一氧化氮合酶基因Glu298Asp多态性的关系

背景：诸多研究认为血管内皮型一氧化氮合酶(endothelial nitric oxide synthase，eNOS)基因多态性与心、脑、肾疾病存在相关性，但eNOS—Glu298Asp与中国老年人心肌梗死的关系是否相关尚不明确。设计：以诊断为依据的病例对照研究。目的：探讨老年人血管内皮型一氧化氮合酶基因Glu298Asp多态性的分布，及其与老年心肌梗死的关系。地点、对象和方法：37例老年心肌梗死患者为病例组，均为南京医科大学第一附属医院门诊及住院患者，其中20例既往无高血压史者为病例亚组；172例本院体检中心复检者(对照组)，其中92例既往无高血压者为对照亚组，分别检测病例组和对照组的身高、体质量、空腹血脂等指标，采用聚合酶链反应(polymerase chain reaction，PCR)和限制性片断长度多态性(restriction fragment length polymorphism，RFLP)检测eNOS基因Glu298Asp多态性。主要观察指标：4组老年人eNOS基因Glu298Asp多态性及298Asp等位基因频率。结果：病例组Glu／Asp基因型高于对照组(32．43％和18．02％)，两组eNOS基因Glu298Asp多态性构成差异有显著性意义(x^2=3．87，P&;lt;0．05)。病例亚组Glu／Asp基因型(35．00％)高于对照亚组(10．87%)，差异有显著性意义(x^2=7．43，P&;lt;0．01)。病例组298Asp等位基因频率高于对照组，差异无显著性意义(P&;gt;0．05)。病例亚组298Asp等位基因频率高于对照亚组，差异有显著性意义(x^2=6．82，P&;lt;0．01)。结论：eNOS基因Glu298Asp多态性在中国老年人群中存在，Glu／Asp基因型和298Asp等位基因可能是中国老年人心肌梗死的遗传易感指标。     

云南汉族eNOS/ET-2基因多态性与高血压的相关性研究

目的探讨eNOS、ET-2基因多态性与高血压的相关性。方法采用病例-对照相关性研究策略,选择三代居住在云南的汉族作为研究对象,用基因芯片检测技术,对100例高血压患者及97例健康对照者进行eNOS Glu298Asp(EE、ED、DD)、ET-2A985G(AA、AG、GG)位点基因多态性检测。用OddRatio估计相对危险度。结果云南汉族97例健康人群中:(1)eNOS Glu298Asp位点的EE、ED、DD基因型频率分别是0.845、0.144、0.011;E和D等位基因频率分别是0.918、0.082。(2)ET-2A985G位点的AA、AG、GG基因型频率分别是0.020、0.258、0.722;A和G等位基因频率分别是0.149、0.851。(3)云南汉族100例高血压患者中,ET-2A985G(AA、AG、GG)位点基因型多态性频率与对照组比较,差异无统计学意义。但ET-2A985G位点G等位基因频率(0.925)与对照组(0.851)比较,差异有统计学意义(χ2=5.507、P=0.019),Odd Ratio=2.168(95%CI:1.123～4.184)。(4)eNOS Glu298Asp位点的DD基因型频率(0.01)与对照组(0.01)比较,差异无统计学意义。结论云南汉族中eNOS Glu298Asp突变对高血压的发生意义不大。ET-2A985G等位基因可能与高血压的易感性相关。     

内皮型一氧化氮合酶基因G894T多态性与反复自然流产的关系

无目的:探讨内皮型一氧化氮合酶(endothelial nitricoxide synthase,eNOS)基因第7外显子G894T多态性与反复自然流产发病的关系。方法:应用PCR-RFLP方法,对67例反复自然流产患者(自然流产组)和72例正常妊娠妇女(对照组)的eNOS基因G894T多态性进行检测。结果:自然流产组eNOS基因Glu/Glu、Glu/Asp、Asp/Asp基因型频率分别为73.1%、28.4%、0,Glu/Asp基因型和Asp等位基因频率虽然高于对照组,但差异均无显著性(χ2=2.58、χ2=2.26,均P>0.05)。携带Asp等位基因个体发生自然流产的相对风险无明显增加(OR=1.78,95%CI0.84～3.79)。结论:eNOS基因G894T多态性与自然流产发病无明显关联。     

脑梗死患者一氧化氮合酶基因多态性及其对一氧化氮的影响

目的观察脑梗死患者内皮型一氧化氮合酶(eNOS)基因多态性及一氧化氮(NO)变化情况。方法采用前瞻性病例对照研究,脑梗死组193例,均为发病2周内经头颅CT或MRI证实存在颈内动脉分布区梗死灶者,对照组103例为正常体检者。对两组eNOS基因4号内含子多态性进行测定,并采用Griess重氮化反应法和酶标法分别检测血清NO含量、NOS活性。结果脑梗死组eNOS基因4号内含子a等位基因(eNOS4a)携带者48例,对照组为12例,携带频率有显著性差异(χ2=8.86,P=0.003);经Logistic回归分析,eNOS4a携带是脑梗死的独立危险因素(P=0.032);脑梗死组NO产物浓度中位数为6.04(3.83～11.49)μmol/L,低于对照组6.89(4.64～12.43)μmol/L(P=0.022)。eNOS4a携带者NO产物浓度中位数为5.07(3.18～7.62)μmol/L,低于非携带者6.86(4.39～11.76)μmol/L(P=0.001)。脑梗死组NOS活性为(2.97±1.47)U/ml,对照组(3.16±1.46)U/ml,无显著性差异(P=0.517)。eNOS4a携带者NOS活性(2.77±1.13)U/ml,与非携带者(3.12±1.54)U/ml无显著性差异(P=0.100)。结论eNOS4a携带可能通过减少NO生成而在脑梗死发生过程中发挥作用。     

内皮型一氧化氮合酶基因与老年人冠心病的相关性研究

目的探讨内皮型一氧化氮合酶（endothelial nitric oxide synthase，eNOS）基因外显子7的Glu298Asp与汉族人群冠心病（CHD）及老年人CHD发病的关系。方法选取123例CHD患者和107例正常对照组人群，应用聚合酶链反应．限制性片段长度多态性（PCR-RFLP）分析技术检测eNOS基因Glu298Asp多态性。结果①eNOS基因Glu／Glu、Glu／Asp、Asp／Asp基因型频率CHD组分别为78.9％、20．3％、0．81％和对照组分别为89．7％、10．3％和0．0％；②Glu／Asp＋Asp／Asp型和Asp等位基因频率CHD组（21．1％and10．9％）显著高于对照组（10．3％and5．2％）（P〈0．05），Asp等位基因对≥60岁老年人发生CHD的风险增高，Or=2．43，95％CI：1．22～4．86（P〈0．05）。结论eNOS基因Asp等位基因可能是汉族老年人CHD发病的遗传易感因素之一。     

脑外伤脑脊液中兴奋性氨基酸测定及其意义

目的探讨脑外伤患者脑脊液中兴奋性氨基酸的变化.方法用邻苯二甲醛柱前衍生后,采用梯度高效液相色谱荧光检测法测定42例脑外伤,9例对照者脑脊液中兴奋性氨基酸--天门冬氨酸(Asp)和谷氨酸(Glu).结果 42例脑外伤患者脑脊液中Asp,Glu测值(Asp:1.878±0.729 μmol/L, Glu:7.985±6.325 μmol/L)明显高于正常对照组(Asp:1.362±0.220,P＜0.05),Glu:1.914±1.507,P＜0.001).26例重伤组脑脊液中Asp,Glu测值(2.402±1.157 μmol/L,10.252±6.570 μmol/L)明显高于轻伤组(1.732±0.595 μmol/L,P＜0.001,4.301±3.741 μmol/L,P＜0.05).脑外伤预后良好(良好;中残)组(Asp:1.835±0.705 μmol/L,Glu:6.307±4.171 μmol/L,n=24)与预后不良(重残;植物生存;死亡)组(Asp:2.588±1.089 μmol/L,Glu:12.530±7.269 μmol/L,n=18)相比较,二组差异有非常显著意义(Asp:P＜0.01,Glu:P＜0.001).结论脑外伤患者伤情愈重,脑脊液中兴奋性氨基酸浓度愈高;浓度愈高,脑外伤预后愈差.     

亚甲基四氢叶酸还原酶C677T基因多态性与原发性高血压患者颈动脉粥样斑块形成的相关性研究

目的研究同型半胱氨酸代谢关键酶亚甲基四氢叶酸还原酶(MTHFR)C677T基因多态性与原发性高血压患者颈动脉粥样硬化斑块形成的相关关系。方法选取原发性高血压患者210例,应用彩色超声仪进行颈动脉检查,其中斑块组120例,无斑块组90例;应用聚合酶链反应检测其MTHFR C677T基因多态性,用酶联免疫吸附法测定血浆同型半胱氨酸水平,用SPSS 17.0统计软件进行数据分析,计量资料两组比较采用t检验,多组间比较采用单因素方差分析,计数资料采用χ2检验。结果斑块组MTHFR TT基因型频率及T等位基因频率与无斑块组比较明显升高(26.6%vs.12.2%,χ2=6.618,P<0.05;47.1%vs.37.2%,χ2=4.084,P<0.05)。斑块组血浆同型半胱氨酸水平明显高于无斑块组[(12.42±3.68)μmol/L vs.(9.74±3.56)μmol/L,t=5.296,P<0.05]。斑块组高血压患者TT基因型的同型半胱氨酸水平[(14.25±3.82)μmol/L]显著高于CT型[(12.1±3.36)μmol/L]和CC型[(11.3±2.87)μmol/L](F=7.21,P<0.05),无斑块组高血压患者TT基因型的同型半胱氨酸水平[(12.89±4.45)μmol/L]显著高于CT型[(9.52±3.15)μmol/L]和CC型[(9.01±3.27)μmol/L](F=5.70,P<0.05)。结论 MTHFR C677T基因多态性可能与高血压患者颈动脉粥样斑块形成有关,位点C677→T基因突变可能通过高同型半胱氨酸血症促进动脉粥样硬化的发展。     

缺血性脑卒中患者半胱氨酸与PON-1 Q192R基因多态性的研究

目的探讨缺血性脑卒中患者同型半胱氨酸(Hcy)与PON-1 Q192R基因多态性的相关性。方法采用循环酶联免疫法检测血浆Hcy浓度以及使用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法检测140例缺血性脑卒中患者(病例组)和117名健康者(对照组)PON-1 Q192R基因多态性。结果病例组和对照组平均空腹血浆Hcy浓度分别为(14.02±4.94)μmol/L和(11.64±4.18)μmol/L,两组差异有统计学意义(t=4.09,P<0.001);将病例组和对照组作为一个研究整体发现:PON-1QQ型、QR型、RR型的平均空腹血浆Hcy浓度分别是(13.34±3.91)μmol/L、(13.14±4.98)μmol/L、(13.30±4.31)μmol/L,经方差分析,PON-1各基因型间血浆Hcy浓度差异无统计学意义(F=0.033,P=0.967)。结论血浆Hcy浓度升高与缺血性卒中有关,并且缺血性脑卒中患者Hcy与PON-1 Q192R基因多态性无关。     

云南汉族健康人群6个原发性高血压候选基因多态性分布

目的 探讨RAS、血管内皮和钠肽系统中血管紧张素原(AGT),血管紧张素转化酶(ACE),内皮型-氧化氮合酶(eNOS),内皮素-2(ET-2),心钠素(ANP)和钠肽受体C(NPRC)等6个高血压候选基因多态性在云南汉族健康人群中的分布,为进一步研究它们在原发性高血压等心血管疾病发生中的作用提供当地信息.方法 用基因芯片检测技术,对97例健康者进行AGT M235T (MM,MT,TT);ACE I/D(II,ID,DD);eNOS Glu298Asp(EE,ED,DD);ET-2 A985G( AA,AG,GG);ANPT2238C(TT,TC,CC)和NPRC A-55C(AA,AC,CC)等位点基因多态性检测.结果 云南汉族97例健康人群中:①AGT M235T位点的MM,MT,TT基因型频率分别是0.052,0.381,0.567;M和T的等位基因频率分别是0.242,0.758.②ACE I/D突变的II,ID,DD基因型频率分别为0.340,0.598,0.062;I和D等位基因频率分别是0.680,0.320.③eNOS Glu298Asp位点的EE,ED,DD基因型频率分别是0.845,0.144,0.011;E和D等位基因频率分别是0.918,0.082.④ET-2 A985G位点的AA,AG,GG基因型频率分别是0.020,0.258,0.722;A和G等位基因频率分别是0.149,0.851.⑤ANPT2238C位点的TT,TC基因型频率分别是0.959,0.041,未检出CC基因型;T和C等位基因频率分别是0.979,0.021.⑥NPRC A-55C的AC,CC基因型频率分别是0.763,0.237,未检出AA基因型;A和C等位基因频率分别是0.381,0.619.结论 云南汉族健康人群AGT M235T,ACE I/D,eNOS Glu298Asp(E298D),ET-2 A985G,ANP T2238C和NPRC A-55C等6个位点基因多态性有地区特征.     

Endothelial nitric oxide synthase gene polymorphisms and risk of coronary artery disease

BACKGROUND: Endothelial nitric oxide synthase (eNOS) could be a candidate gene for coronary artery disease (CAD). This study investigated the relationship of the eNOS Glu(298)-->Asp and T(786)-->C polymorphisms with the presence and severity of CAD in the Italian population. METHODS: We enrolled 415 unrelated individuals who underwent coronary angiography. The severity of CAD was expressed by means of the Duke score. The eNOS Glu(298)-->Asp and T(786)-->C variants were analyzed by PCR. RESULTS: There was significant linkage disequilibrium between the two eNOS polymorphisms (P <0.0001). Both variants were significantly associated with the occurrence and severity of CAD (P = 0.01 and 0.004 for Glu(298)-->Asp and T(786)-->C, respectively). The risk of CAD was increased among individuals homozygous for the C allele of the T(786)-->C polymorphism compared with individuals homozygous for the T allele (odds ratio = 2.5; P <0.01) and was independent of the other common risk factors (P = 0.04). Moreover, individuals with both the Asp/Asp genotype of the Glu(298)-->Asp polymorphism and at least one C allele of the T(786)-->C variant in the promoter region of the eNOS gene had an increased risk of CAD (odds ratio = 4.0; P <0.001) and a significantly higher mean Duke score (26.2 +/- 2.9 vs 45.2 +/- 3.7; P = 0.002) compared with individuals with the TT genotype and the Glu allele. CONCLUSIONS: The present study provides evidence that the Glu(298)-->Asp and T(786)-->C polymorphisms of the eNOS gene are associated with the presence and severity of angiographically defined CAD in the Italian population and that those individuals carrying both eNOS variants simultaneously might have a higher risk of developing CAD.     

Lack of association of the Glu298Asp polymorphism of endothelial nitric oxide synthase with manifest coronary artery disease,carotid atherosclerosis and forearm vascular reactivity in two Austrian populations

OBJECTIVE: Conflicting data exists about the possible contribution of the homozygous Asp/Asp genotype of the Glu298Asp polymorphism of endothelial nitric oxide synthase to human atherosclerotic vascular disease. We investigated the polymorphism in two independent study populations: a case-control study including patients with angiographically verified coronary artery disease (CAD) on the one hand and a cross-sectional epidemiological study on the other hand. METHODS: The Glu298Asp polymorphism was determined by PCR-RFLP as established. In the case-control study (240 patients and 248 controls) a possible association between the polymorphism and CAD, and age of onset of CAD and myocardial infarction was investigated. In the cross-sectional epidemiological study (932 subjects) intima-media thickness (IMT) of the carotid artery as well as morphological plaque burden and forearm vascular reactivity (peak postischemic reactive hyperaemia, determined by venous occlusion plethysmography) were measured. RESULTS: In the case-control study genotype distribution (Glu/Glu; Glu/Asp; Asp/Asp) was not different between the CAD patients (43/46/11%) and the controls (49/41/10%, P = NS). No association of the polymorphism with age of onset of CAD or myocardial infarction was found. In the epidemiological study no influence of the genetic variant on IMT was observed after correction for classical determinants of IMT (average IMT: Asp/ Asp: 0.077 +/- 0.011 mm; Glu/Glu and Glu/Asp: 0.080 +/- 0.012 mm, P = NS). Forearm vascular reactivity was also not different between homozygous Asp/Asp subjects and Glu/Glu and Glu/Asp subjects (peak-reactive hyperaemia 20.1 +/- 7.3 mL min-1 100 mL-1 vs. 20.0 +/- 6.5 mL min-1 100 mL-1, P = NS). CONCLUSIONS: Our results suggest that there is no association of the Glu298Asp polymorphism with coronary or carotid atherosclerosis or forearm vascular reactivity in these populations recruited in a country with a rather high risk for atherosclerosis. We suggest additional investigations to be performed in populations at different risk for coronary events to further elucidate the possible contribution of this polymorphism to vascular disease.     

Endothelial nitric oxide synthase (Glu298Asp) polymorphism is an independent risk factor for migraine with aura

OBJECTIVE: The aim of the present study was to evaluate whether the functional endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphism, which has been demonstrated to decrease the endothelial NOS activity, might be a risk factor for migraine. BACKGROUND: It has widely demonstrated that nitric oxide (NO) is involved in migraine pathogenesis. Several genetic risk factors have been associated with migraine, but no study has unraveled a possible relationship between migraine and eNOS Glu298Asp. Methods.-One hundred fifty-six migraine patients and 125 healthy nonheadache volunteers entered the study. Demographic and clinical characteristics were carefully recorded, and a neurological workup was performed. RESULTS: eNOS AspAsp homozygous patients had a 3-fold time risk for migraine with aura (MA) when compared to migraine without aura (MO) patients (OR-3.02, 95% CI-1.21 to 7.51), and more than 2-fold time increased risk when compared to control subjects (OR-2.21, 95% CI-1.00 to 5.04). In migraine patients, no difference in age at onset, mean attack's intensity, family history for any of the studied comorbidities, or the presence of comorbidities was found in eNOS AspAsp homozygous compared to eNOS GluGlu or eNOS GluAs carriers. CONCLUSIONS: Homozygous Asp298, a common variant of the eNOS gene, is an independent risk factor for MA in this study population.     

Endothelial nitric oxide synthase Glu(298)-->Asp polymorphism, carotid atherosclerosis and intima-media thickness in a general population sample

The Glu(298)-->Asp (E298D; 894G-->T) polymorphism of eNOS (endothelial nitric oxide synthase) has been related with cardiovascular disease. In the present study, we investigated the association of Glu(298)-->Asp with atherosclerotic plaques in different carotid vessel segments and with carotid IMT (intima-media thickness). The Glu(298)-->Asp eNOS polymorphism was determined by 5'-exonuclease assay among 2448 participants of the SHIP (Study of Health in Pomerania). Mean and maximum common carotid IMT, as well as carotid atherosclerosis, were measured by high-resolution ultrasound. The Asp/Asp(298) genotype was associated with an increased risk of atherosclerotic plaques at the level of the common carotid arteries [multivariate odds ratio, 1.57 and 95% CI (confidence interval), 1.05-2.34; P=0.025], but not in the carotid bifurcations or internal or external carotid arteries. Glu(298)-->Asp genotype was not associated with carotid IMT in the whole sample. However, the Asp/Asp(298) genotype was independently associated with both higher mean [adjusted increase by 0.046 mm (95% CI, 0.013-0.078); P=0.006] and maximum carotid IMT [0.137 mm (95% CI, 0.064-0.209); P<0.001] in the low-risk group of subjects without carotid atherosclerosis. In conclusion, the Asp/Asp(298) genotype is associated with atherosclerosis in the common carotid arteries and, in a low-risk group, also with carotid IMT. This suggests that the association of the Glu(298)-->Asp genotype with atherosclerosis in the carotid arteries is site-specific and is modified by overall cardiovascular risk.     

Association between the eNOS (Glu298Asp) and the RAS genes polymorphisms and premature coronary artery disease in a Turkish population

BACKGROUND: The renin-angiotensin system (RAS) and endothelial nitric oxide (NO) affect the pathogenesis of atherosclerosis and prognosis of coronary artery disease (CAD). Previous epidemiologic data suggested that genetic factors are more likely to affect young rather than old people. Our objective was to investigate the association between the polymorphisms of eNOS (Glu298Asp) and the RAS genes and premature CAD in a Turkish population. METHODS: A total of 115 Turkish patients with premature CAD and 83 controls were included in the study. ACE I/D, AT1R A/C, AGT T/M and eNOS Glu298Asp gene polymorphisms were analysed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: It was found that increased premature CAD risk is associated with higher frequencies of the ACE DD [OR: 2.600 (CI 95% 1.395-4.847, p=0.002)], AGT MM [OR=2.407 (CI 95% 1.267-4.573, p=0.007)] and eNOS 894TT [OR=17.000 (CI 95% 3.952-73.125, p<0.001)] genotypes. Carriers of ACE DD+eNOS 894TT (p=0.002), AGT MM+eNOS 894TT (p=0.001), AT1R AA+eNOS 894TT and AT1R non-AA+eNOS 894TT (p=0.002) genotypes were significantly associated with the risk of premature CAD. CONCLUSIONS: This study indicates a synergistic contribution of RAS genes (ACE I/D, AGT T/M, AT1R T/C) and eNOS Glu298Asp polymorphisms to the development of the premature CAD.     

Genetic risk factors for coronary artery spasm: significance of endothelial nitric oxide synthase gene T-786-->C and missense Glu298Asp variants.

BACKGROUND: We recently identified two endothelial nitric oxide synthase (eNOS) gene polymorphisms, Glu298Asp and T-786-->C, which are independently associated with coronary spasm. eNOS gene intron 4b/a polymorphism is also reported to be involved in smoking-dependent coronary artery disease. The genetic linkage among these polymorphisms remains unknown. Also, it is unclear which variant is most responsible for coronary spasm. In the present study, we first examined the genetic linkage among these three variants. Next, we studied the risk factors of coronary spasm by using all significant genetic and conventional risk factors in a large-scale study. METHODS: The genotype and allele frequencies for the T-786-->C, intron 4b/a, and Glu298Asp variants were assessed in 423 randomly selected DNA samples to examine their genetic linkages. The relative capacities of all risk factors to predict coronary spasm were then analyzed using multiple logistic regression in 201 patients with coronary spasm and 345 volunteers. RESULTS: Comparison of allele frequencies revealed that the eNOS intron 4a allele was significantly linked to the T-786-->C mutation (P < 0.00001), whereas there was not a linkage between the intron 4a allele and the Glu298Asp variant (P = 0.1437) or between the Glu298Asp variant and the T-786-->C mutation (P = 0.1996). Multiple logistic regression revealed that the most predictive independent risk factor for coronary spasm was the T-786-->C mutation (P < 0.001), followed by cigarette smoking (P < 0.001), hypertension (P = 0.004), and the Glu298Asp variant (P = 0.028). CONCLUSIONS: We found that the T-786-->C mutation and the intron 4a allele are in linkage disequilibrium. We previously showed that the T-786-->C mutation reduced eNOS gene promoter activity. In that context, our results strongly suggest that the T-786-->C mutation underlies the functional characteristics of the intron 4a allele. Further, multiple logistic regression analysis revealed that the T-786-->C mutation is the most predictive risk factor for coronary spasm, followed by cigarette smoking. Given that those effects are potentially additive, patients carrying the eNOS gene variants should be strongly cautioned against smoking.     

Endothelial nitric oxide synthase G894T (GLU298ASP) polymorphism is associated with hypotension in patients with E. coli bacteremia but not in bacteremia caused by a gram-positive organism

Nitric oxide (NO) as a vasoactive substance is a crucial element in the pathogenesis of sepsis. Endothelial NO synthase (eNOS) is, in turn, a key regulator of vascular NO production. The eNOS gene polymorphism at position 894 (G>T, Glu298Asp) resulting in T allele has been studied in the context of vascular diseases, but its role in sepsis has not yet been explored. We here studied the effect of eNOS Glu298Asp polymorphism on the clinical course of the disease in patients with bacteremia. The study comprised 147 patients with bacteremia caused by Staphylococcus aureus, Streptococcus pneumoniae, beta-hemolytic streptococci, or Escherichia coli. Laboratory findings and clinical data were registered on admission and during 6 consecutive days. The polymorphism of eNOS gene, G894T, was genotyped. Carriage of the T allele was associated with low MAP (P = 0.004) and high Sequential Organ Failure Assessment score (P = 0.001) in patients with E. coli bacteremia. The effect on blood pressure was most prominent in the early stage of the disease (MAP on admission = 52 mmHg in T-allele carriers vs. 91 mmHg in noncarriers; P < 0.001). However, the same was not detected in bacteremia caused by a gram-positive organism (S. aureus, S. pneumoniae, or beta-hemolytic streptococci). The Glu298Asp polymorphism had no effect on case fatality in any pathogen. Carriage of the T allele of the eNOS gene is a risk factor for hypotension in patients with E. coli bacteremia but not in bacteremia caused by a gram-positive organism.     

Endothelial nitric oxide synthase G894T gene polymorphism in Chilean subjects with coronary artery disease and controls

BACKGROUND: Nitric oxide (NO) from the endothelium, produced by oxidation of l-arginine to L-citruline for the action at the endothelial nitric oxide synthase (eNOS), is considered an important atheroprotective factor. The Glu298Asp (G894T) polymorphic variant of the eNOS gene has been implicated in the development of coronary artery disease (CAD). We investigated the association between occurrence of CAD documented by angiography and the G894T polymorphism of the NOS3 gene in Chilean individuals. METHODS: A total of 112 unrelated patients with diagnosis of CAD and 72 controls were included in this study. G894T gene polymorphism was analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: The frequency of TT homozygous genotype for G894T polymorphism was 7% in CAD patients and 1% in the control group. However, the genotype distribution and allele frequencies were not significantly different between CAD and control subjects (P>0.05). Moreover, the odds ratio for CAD associated with the T variant failed to reach statistical significance (OR=1.5; 95% CI: 0.87-2.59, P>0.05). CONCLUSION: These findings suggest that the G894T polymorphism of the eNOS gene was not associated with CAD in Chilean individuals.