OBJECTIVETo investigate the relationship between angiotensin converting enzyme (ACE) gene and endothelial dysfunction.

METHODSOne hundred and ten type 2 diabetic patients without angiopathy were selected randomly, and PCR technique was used to determine their ACE genotypes. High resolution ultrasonography was performed to measure the changes in brachial artery diameter at rest, after reactive hyperemia (with increased flow producing an endothelium-dependent dilation) and after sublingual glyceryltrinitrate (GNT, an endothelium-independent dilator). Meanwhile, 50 healthy individuals were selected randomly as controls.

RESULTSIn type 2 diabetes mellitus and control groups, the percentages for flow-mediated arterial dilation in patients with DD genotypes were 3.38% and 3.67% respectively, which were significantly lower than those in patients with II genotypes (4.12% and 4.68% respectively, P<0.05). The baseline blood vessel size, baseline blood flow and GNT induced dilation in both groups showed no significant differences among ACE genotypes (P>0.05). By multiple stepwise regression analysis, reduced flow-mediated arterial dilation was associated with age, baseline vessel size, low density lipoprotein cholesterol(LDL-C), Lp(a), D allele, fasting blood glucose (FBG), postparandial blood glucose (PPBG), HbA1c, duration of diabetes in type 2 diabetic patients (P<0.0005).

CONCLUSIONACE DD genotype is related to endothelium-dependent arterial dilation in the early stage of type 2 diabetes mellitus and in healthy individuals.

Adult ; Aged ; Brachial Artery ; physiopathology ; Diabetes Mellitus, Type 2 ; enzymology ; genetics ; physiopathology ; Diabetic Angiopathies ; genetics ; physiopathology ; Endothelium, Vascular ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Peptidyl-Dipeptidase A ; genetics ; Polymerase Chain Reaction

Previous evidence supports the important role that oxidative stress (OxS) plays in metabolic syndrome (MetS)-related manifestations. We determined the relationship between the number of MetS components and the degree of OxS in MetS patients. In this comparative cross-sectional study from the LIPGENE cohort, a total of 91 MetS patients (43 men and 48 women; aged between 45 and 68 years) were divided into four groups based on the number of MetS components: subjects with 2, 3, 4 and 5 MetS components (n=20, 31, 28 and 12, respectively). We measured ischemic reactive hyperemia (IRH), plasma levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), total nitrite, lipid peroxidation products (LPO), hydrogen peroxide (H2O2), superoxide dismutase (SOD) and glutathione peroxidase (GPx) plasma activities. sVCAM-1, H2O2 and LPO levels were lower in subjects with 2 or 3 MetS components than subjects with 4 or 5 MetS components. IRH and total nitrite levels were higher in subjects with 2 or 3 MetS components than subjects with 4 or 5 MetS components. SOD and GPx activities were lower in subjects with 2 MetS components than subjects with 4 or 5 MetS components. Waist circumference, weight, age, homeostatic model assessment-beta, triglycerides (TGs), high-density lipoprotein and sVCAM-1 levels were significantly correlated with SOD activity. MetS subjects with more MetS components may have a higher OxS level. Furthermore, association between SOD activity and MetS components may indicate that this variable could be the most relevant OxS biomarker in patients suffering from MetS and could be used as a predictive tool to determine the degree of the underlying OxS in MetS.
Aged ; Anthropometry ; Antioxidants/metabolism ; Biological Markers/metabolism ; Blood Pressure ; Endothelium, Vascular/pathology/physiopathology ; Female ; Glutathione Peroxidase/blood ; Humans ; Hydrogen Peroxide/metabolism ; Hyperemia/blood/physiopathology ; Male ; Metabolic Syndrome X/blood/enzymology/*pathology/physiopathology ; Middle Aged ; Nitrites/blood ; *Oxidative Stress ; Regression Analysis ; Superoxide Dismutase/blood ; Vascular Cell Adhesion Molecule-1/metabolism

The incidence of cardiovascular disease is predicted to increase as the population ages. There is accumulating evidence that arginase upregulation is associated with impaired endothelial function. Here, we demonstrate that arginase II (ArgII) is upregulated in aortic vessels of aged mice and contributes to decreased nitric oxide (NO) generation and increased reactive oxygen species (ROS) production via endothelial nitric oxide synthase (eNOS) uncoupling. Inhibiting ArgII with small interfering RNA technique restored eNOS coupling to that observed in young mice and increased NO generation and decreased ROS production. Furthermore, enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxation responses to acetylcholine in aged vasculature were markedly improved following siRNA treatment against ArgII. These results might be associated with increased L-arginine bioavailability. Collectively, these results suggest that ArgII may be a valuable target in age-dependent vascular diseases.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology ; Aging ; Animals ; Aorta/enzymology/physiopathology ; Arginase/genetics/*metabolism ; Endothelium, Vascular/*enzymology/physiopathology ; Enzyme Induction ; Gene Knockdown Techniques ; Mice ; Mice, Inbred C57BL ; Nitric Oxide/metabolism ; Nitric Oxide Synthase Type III/*metabolism ; RNA, Small Interfering/genetics ; Reactive Oxygen Species/metabolism ; Up-Regulation ; Vasoconstriction/drug effects

Hypertension is associated with endothelial dysfunction and increased cardiovascular risk. Caveolin-1 regulates nitric oxide (NO) signaling by modulating endothelial nitric oxide synthase (eNOS). The purpose of this study was to examine whether HMG-CoA reductase inhibitor improves impaired endothelial function of the aorta in spontaneous hypertensive rat (SHR) and to determine the underlying mechanisms involved. Eight-week-old male SHR were assigned to either a control group (CON, n=11) or a rosuvastatin group (ROS, n=12), rosuvastatin (10 mg/kg/day) administered for eight weeks. Abdominal aortic rings were prepared and responses to acetylcholine (10-9-10-4 M) were determined in vitro. To evaluate the potential role of NO and caveolin-1, we examined the plasma activity of NOx, eNOS, phosphorylated-eNOS and expression of caveolin-1. The relaxation in response to acetylcholine was significantly enhanced in ROS compared to CON. Expression of eNOS RNA was unchanged, whereas NOx level and phosphorylated-eNOS at serine-1177 was increased accompanied with depressed level of caveolin-1 in ROS. We conclude that 3-Hydroxy-3-methylglutaryl Coenzyme-A (HMG-CoA) reductase inhibitor can improve impaired endothelial dysfunction in SHR, and its underlying mechanisms are associated with increased NO production. Furthermore, HMG-CoA reductase inhibitor can activate the eNOS by phosphorylation related to decreased caveolin-1 abundance. These results imply the therapeutic strategies for the high blood pressure-associated endothelial dysfunction through modifying caveolin status.
Acetylcholine/metabolism ; Animals ; Aorta/metabolism/physiopathology ; Blood Pressure/drug effects ; Caveolin 1/*metabolism ; Down-Regulation ; Drug Administration Schedule ; Endothelium, Vascular/*drug effects/physiopathology ; Fluorobenzenes/administration & dosage/*pharmacology ; Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage/*pharmacology ; Hypertension/enzymology/metabolism/*physiopathology ; Male ; Nitric Oxide/blood ; Nitric Oxide Synthase Type III/*metabolism ; Phosphorylation ; Pyrimidines/administration & dosage/*pharmacology ; Rats ; Rats, Inbred SHR ; Sulfonamides/administration & dosage/*pharmacology ; Vasodilation/drug effects

OBJECTIVETo explore the molecular biological mechanism for tanshinone II A reversing left ventricular hypertrophy, it would be studying the effect of tashinone on the endothelial nitric oxide synthase (eNOS) and protein kinase C (PKC) in the hypertrophic cadiocyte of rats suffered abdominal aorta constriction.

METHODSD rats were operated with abdominal aorta constriction and 8 rats were done with sham surgery. After 4 weeks, all rats were divided into 4 groups: myocardial hypertrophy group, low dose tanshinone II A group (10 mg x kg(-1) x d(-1)), high dose tanshinone II A group (20 mg x kg(-1) x d(-1)) and valsartan group (10 mg x kg(-1) d(-1) intragastric administration). 8 weeks later, the rats were used to measure the left ventricular mass index (LVMI) with the tissue of left ventricle and myocardial fiber dimension (MFD) by pathological section and HE stain, to detect the nitric oxide content by nitrate reductase, to detect the genic expression of eNOS by RT-PCR and to detect the activity of protein kinase C (PKC) by Western blotting.

RESULT1) The blood pressure in group myocardial hypertrophy [(186 +/- 13) mmHg] and tansginone II A [low and high dose (188 +/- 11,187 +/- 14) mmHg] was obviously higher than that in group sham surgery and valsartan group [vs (117 +/- 8, 136 +/- 15) mmHg, P < 0.01]. But there was no difference between group myocardial hypertrophy and group tanshinone II A (low and high dose). 2) The LVMI and MFD were obviously higher in group tanshinone II A low and high dose) and group valsartan than those in group sham surgery (P < 0.05), and lower than those in group myocardial hypertrophy (P < 0.01). 3) The NO level was obviously higher in group tanshinone II A (low and high dose) and group valsartan than that in group myocardial hypertrophy (12.78 +/- 1.66, 11.95 +/- 1.39, 12.26 +/- 2.08 vs 5.83 +/- 1.06) micromol x L(-1), (P < 0.01 ), and lower than that in group sham surgery (vs 19.35 +/- 1.47) micromol x L(-1), (P < 0.05). 4) The expressive level of eNOS mRNA and protein in myocardial hypertrophy group was less than that in other groups (P < 0.01). And valsartan group was less than tanshinone II A groups and sham surgery group (P < 0.05), but there were no difference among the two tanshinone II A groups and sham surgery group. 5) The level of PKC protein in group myocardial hypertrophy was obviously higher than that in all the other groups (1.291 +/- 0.117 vs 0.563 +/- 0.094, 0.605 +/- 0.051, 0.519 +/- 0.062, 0.827 +/- 0.086, P < 0.01), and the level in group valsartan was higher than that in group sham operation and group tanshinone II A (low and high dose).

CONCLUSIONNO/NOS system in local myocardium has close relationship with the pathological process for myocardial hypertrophy. Tanshinone II A can produce the pharmacological action to reverse myocardial hypertrophy by inhibiting the activity of PKC and promoting the genic expression of eNOS in local myocardium and the production of endogenous NO.

Animals ; Aorta, Abdominal ; pathology ; Benzofurans ; pharmacology ; Blood Pressure ; drug effects ; Cardiomyopathy, Hypertrophic ; complications ; enzymology ; physiopathology ; Constriction, Pathologic ; complications ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Endothelium, Vascular ; drug effects ; enzymology ; Female ; Gene Expression Regulation, Enzymologic ; drug effects ; Heart Ventricles ; drug effects ; metabolism ; pathology ; physiopathology ; Male ; Myocytes, Cardiac ; drug effects ; enzymology ; pathology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; genetics ; metabolism ; Protein Kinase C ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats

OBJECTIVES: The aging process affects responsiveness and other functions of endothelium and vascular smooth muscle cells, predisposing the old vessels to the development of atherosclerotic lesions. Endothelial nitric oxide synthase (ecNOS) gene polymorphisms were shown to affect the occurrence of acute myocardial infarction (AMI). We hypothesized that aging may affect the association between the ecNOS gene polymorphism and AMI. METHODS: We investigated the age-related distribution of the ecNOS gene a/b polymorphism in 121 male AMI patients and 206 age-matched healthy male controls. RESULTS: The aa, ab and bb genotypes were found in 1, 49 and 156 cases among the control subjects and 5, 23 and 93 cases among the AMI patients, respectively. There was a significant correlation between the ecNOS polymorphism and AMI (p +AD0- 0.045). When the correlation was analyzed by age, the significance remained only in the group below the age of 51 (p +AD0- 0.009). The proportion of smokers was increased in the young patients when compared to the old patients (p +AD0- 0.033), indicating that smoking also has greater effect on the younger population. The incidences of hypertension and diabetes mellitus, however, were similar in both populations. CONCLUSION: Our work provides the first evidence that links ecNOS polymorphism to the risk of AMI in relation to age. Young persons who smoke or have ecNOSaa genotype may have an increased risk of developing AMI. The functional as well as structural changes associated with aging in the vascular endothelium may mask the effect of the ecNOS polymorphism in the development of AMI in old persons.
Adult ; Age Distribution ; Aged ; Aged, 80 and over ; Aging/physiology+ACo- ; Chi-Square Distribution ; Comorbidity ; Diabetes Mellitus/epidemiology ; Endothelium, Vascular/enzymology+ACo- ; Genotype ; Human ; Hypertension/epidemiology ; Korea/epidemiology ; Male ; Middle Age ; Myocardial Infarction/physiopathology+ACo- ; Myocardial Infarction/epidemiology ; Nitric-Oxide Synthase/metabolism+ACo- ; Nitric-Oxide Synthase/genetics+ACo- ; Polymerase Chain Reaction ; Polymorphism (Genetics)+ACo- ; Risk Assessment ; Statistics, Nonparametric