Nitrite and tempol combination promotes synergic effects and alleviates right ventricular wall stress during acute pulmonary thromboembolism.

Introduction: The mechanical obstruction and pulmonary vasoconstriction are major determinants of the sudden right ventricular (RV) afterload increases observed during acute pulmonary thromboembolism (APT). Vasodilators and antioxidants agents have been shown to mitigate pulmonary hypertension. We examined whether sodium nitrite and the antioxidant tempol combination could be advantageous in an APT sheep model.

Towards microfluidic-based depletion of stiff and fragile human red cells that accumulate during blood storage.

In this study, the effects of prolonged storage on several biophysical properties of red blood cells (RBCs) were investigated. Single cell deformability was used as an important criterion in determining subgroups of RBCs evolved during storage lesion. A deformability-based microfluidic cell sorting technology was applied, which demonstrates the ability to enrich and separate the less deformable subpopulations of stored blood.

Hemolysis during cardiac surgery is associated with increased intravascular nitric oxide consumption and perioperative kidney and intestinal tissue damage.

Introduction: Acute kidney injury (AKI) and intestinal injury negatively impact patient outcome after cardiac surgery. Enhanced nitric oxide (NO) consumption due to intraoperative intravascular hemolysis, may play an important role in this setting. This study investigated the impact of hemolysis on plasma NO consumption, AKI, and intestinal tissue damage, after cardiac surgery.

Homocysteine and nitrite levels are modulated by MTHFR 677C>T polymorphism in obese women treated with simvastatin.

Higher homocysteine (Hcy) levels are associated with cardiovascular risk. The aim of the present study was to evaluate the effect of simvastatin treatment on circulating Hcy levels in obese women without hypertension, diabetes or dyslipidaemia; and to determine whether the 677C>T polymorphism located in methylenetetrahydrofolate reductase (NAD(P)H) (MTHFR) gene modulates the effects of this treatment on Hcy and nitrite (as a biomarker of nitric oxide (NO) bioavailability). Twenty-five obese women (body mass index ≥ 30 kg/m(2) ) who had received 20 mg/day simvastatin for 6 weeks were enrolled in the study.

The antioxidant tempol decreases acute pulmonary thromboembolism-induced hemolysis and nitric oxide consumption.

Introduction: Acute pulmonary thromboembolism (APT) is a critical condition associated with acute pulmonary hypertension. Recent studies suggest that oxidative stress and hemolysis contribute to APT-induced pulmonary hypertension, possibly as a result of increased nitric oxide (NO) consumption. We hypothesized that the antioxidant tempol could attenuate APT-induced hemolysis, and therefore attenuate APT-induced increases in plasma NO consumption.

Acute cardiac and hemodynamic effects of sildenafil on resistant hypertension.

Purpose: Failure to control blood pressure (BP) despite the use of three or more drugs characterizes resistant hypertension (RHTN). Impaired endothelial function is associated with this condition and phosphodiesterase-5 inhibitors (PDE5i)-inhibiting cGMP breakdown-reduce BP in RHTN patients. We hypothesized that acute administration of PDE5i could ameliorate hemodynamic, endothelial parameters and left ventricular diastolic function (LVDF) in RHTN patients.

Antihypertensive effects of inducible nitric oxide synthase inhibition in experimental pre-eclampsia.

Upregulation of inducible nitric oxide synthase (iNOS) has been reported in both experimental and clinical hypertension. However, although pro-inflammatory cytokines that up-regulate iNOS contribute to pre-eclampsia, no previous study has tested the hypothesis that a selective iNOS inhibitor (1400 W) could exert antihypertensive effects associated with decreased iNOS expression and nitrosative stress in pre-eclampsia. This study examined the effects of 1400 W in the reduced uteroplacental perfusion pressure (RUPP) placental ischaemia animal model and in normal pregnant rats.

The relationship between training status, blood pressure and uric acid in adults and elderly.

Background: Hypertension can be generated by a great number of mechanisms including elevated uric acid (UA) that contribute to the anion superoxide production. However, physical exercise is recommended to prevent and/or control high blood pressure (BP). The purpose of this study was to investigate the relationship between BP and UA and whether this relationship may be mediated by the functional fitness index.

Maternal flow-mediated dilation and nitrite concentration during third trimester of pregnancy and postpartum period.

Objectives: To compare maternal flow-mediated dilation (FMD) of the brachial artery and nitrite concentration between third trimester of pregnancy (3rdT) and postpartum (PP) period. Additionally, we will evaluate whether FMD correlates with nitrite concentration in both periods.

Methods: Eligibility criteria was healthy women with singleton pregnancy, gestational age >28 weeks, nonsmokers, and no personal or family history of vascular disease.

Low nitric oxide bioavailability is associated with better responses to sildenafil in patients with erectile dysfunction.

Erectile dysfunction (ED) is a multifactorial disease associated with vascular dysfunction, low nitric oxide (NO) bioavailability, and oxidative stress. However, it is not known whether low NO bioavailability and oxidative stress affect the responsiveness of ED patients to sildenafil. We tested this hypothesis by studying 28 healthy subjects (control group), 26 patients with ED without comorbidities (ED group), and 18 patients with ED and diabetes mellitus (ED/DM group).

Elevated plasma hemoglobin levels increase nitric oxide consumption in experimental and clinical acute pulmonary thromboembolism.

Objectives: We examined whether experimental lung embolization with autologous blood clots or with the infusion of microspheres increase cell-free hemoglobin levels and nitric oxide consumption by plasma samples from anesthetized lambs. These parameters were also measured in patients with acute pulmonary thromboembolism at baseline conditions and after thrombolysis, and in healthy controls.

Design: Controlled animal and clinical studies.

Blood transfusions increase circulating plasma free hemoglobin levels and plasma nitric oxide consumption: a prospective observational pilot study.

Introduction: The increasing number of reports on the relation between transfusion of stored red blood cells (RBCs) and adverse patient outcome has sparked an intense debate on the benefits and risks of blood transfusions. Meanwhile, the pathophysiological mechanisms underlying this postulated relation remain unclear. The development of hemolysis during storage might contribute to this mechanism by release of free hemoglobin (fHb), a potent nitric oxide (NO) scavenger, which may impair vasodilation and microcirculatory perfusion after transfusion.

Alterations in cyclic GMP levels in preeclampsia may reflect increased B-type natriuretic peptide levels and not impaired nitric oxide activity.

Objectives: We compared nitrite, B-type natriuretic peptide (BNP), and cGMP levels in preeclamptic with those found in healthy pregnant.

Methods: We studied 21 healthy pregnant and 27 preeclamptic. Plasma cGMP and BNP levels were determined by ELISA.

Antihypertensive effects exerted by enalapril in mild to moderate hypertension are not associated with changes in the circulating levels of nitric oxide-related markers.

Purpose: The antihypertensive effects of angiotensin-converting enzyme inhibitors (ACEi) are explained, at least in part, by enhanced bradykinin-dependent nitric oxide (NO) formation and decreased angiotensin II-induced oxidative stress and vasoconstriction. We examined for the first time whether treatment with enalapril increases the plasma levels of markers of NO formation and decreases oxidative stress in mild to moderate hypertensive patients.

Methods: Eighteen untreated hypertensive patients were treated with enalapril 10 mg/day (n=10) or 20 mg/day (n=8) for 60 days.

eNOS haplotype associated with hypertension in obese children and adolescents.

Objective: The aim of our study is to investigate whether genetic polymorphisms in the endothelial nitric oxide synthase (eNOS) gene (in the promoter region T(-786)C, in exon 7 (Glu298Asp) and in intron 4 (4b/4a)) or eNOS haplotypes are associated with hypertension in obese children and adolescents.

Methods: We genotyped 175 healthy (controls), 110 normotensive obese and 73 hypertensive obese children and adolescents. Genotypes were determined by Taqman allele discrimination assay and real-time PCR, and by PCR followed by fragment separation by electrophoresis.

Increased circulating cell-free hemoglobin levels reduce nitric oxide bioavailability in preeclampsia.

Contrasting with increased nitric oxide (NO) formation during healthy pregnancy, reduced NO bioavailability plays a role in preeclampsia. However, no study has examined whether increased NO consumption by enhanced circulating levels of cell-free hemoglobin plays a role in preeclampsia. We studied 82 pregnant women (38 healthy pregnant and 44 with preeclampsia).

Effects of eNOS polymorphisms on nitric oxide formation in healthy pregnancy and in pre-eclampsia.

Pre-eclampsia (PE) is associated with decreased nitric oxide (NO) formation. However, no previous study has examined whether genetic variations in the endothelial NO synthase (eNOS) affect this alteration. We hypothesized that PE decreases NO formation depending on eNOS polymorphisms.

Environmental exposure to methylmercury is associated with a decrease in nitric oxide production.

Some studies have recently suggested that mercury (Hg)-exposed populations face increased risks of cardiovascular diseases, and experimental data indicate that such risks might be due to reductions in nitric oxide bioavailability. However, no previous study has examined whether Hg exposure affects plasma nitrite concentrations in humans as an indication of nitric oxide production. Here, we investigated whether there is an association between circulating nitrite and Hg concentrations in whole blood, plasma and hair from an exposed methylmercury (MeHg) population.

Modulation of nitric oxide formation by endothelial nitric oxide synthase gene haplotypes.

Nitric oxide (NO) is a major regulator of the cardiovascular system. However, the effects of endothelial nitric oxide synthase (eNOS) gene polymorphisms or haplotypes on the circulating concentrations of nitrite (a sensitive marker of NO formation) and cGMP are unknown. Here we examined the effects of eNOS polymorphisms in the promoter region (T-786C), in exon 7 (Glu298Asp), and in intron 4 (4b/4a) and eNOS haplotypes on the plasma levels of nitrite and cGMP.