Serum Nitric Oxide Metabolites Research Articles

Systemic nitric oxide metabolites and the chance of pre-diabetes regression to normoglycemia: A 9-year cohort study.

We aimed to track longitudinal changes of glycemic status in subjects with pre-diabetes (Pre-DM) in relation to their baseline levels of systemic nitric oxide (NO) production [i.e., measured as serum NO metabolites (NOx), crude and body weight (BW)-adjusted NOx to creatinine ratio (NOx-to-Cr)] over 9 years. This cohort study included 541 middle-aged Iranian men and women with Pre-DM, recruited in 2006-2008 and followed up to 2015-2017. The colorimetric Griess method was used to measure serum NOx concentration. Multinomial logistic regression analyses estimated the odds ratios (OR) of Pre-DM regression and progression across tertiles (tertile 3 vs. tertile 1 and tertile 2) of serum NOx, crude, and BW-adjusted NOx-to-Cr ratio. Participants who regressed to normoglycemia (NG) had a higher BW-adjusted NOx-to-Cr ratio than those who developed type 2 diabetes (T2D) or those who remained Pre-DM (0.52±0.34 vs. 0.43±0.25 and 0.48±0.29, P=0.023). Higher BW-adjusted NOx-to-Cr increased chance of returning to NG (OR=2.05, 95% CI= 0.98-4.32, P=0.058) and decreased levels of 2h-serum glucose over time (P time×group=0.025), as well as the decreased overall mean of fasting (106, 95% CI=103-109 vs. 110, 95% CI=108-112 mg/dL, P=0.008) and 2h-serum glucose (153, 95% CI=146-159 vs. 163, 95% CI=158-168 mg/dL, P=0.018). A higher endogenous NO production (i.e., indirectly measured by BW- and Cr-adjusted serum NOx concentration) in Pre-DM subjects is associated with the chance of returning to NG.

Serum levels of Nitric Oxide metabolites in relation to Body Mass Index and Arterial stiffness in young individuals

Introduction: Obesity is a multi-factorial disorder defined as abnormally high levels of body fat accumulation. It is a major emerging pandemic of this century which can be attributed to alterations in eating habits, lifestyle choices and rise in sedentary behaviour. The activation of pro-inflammatory signalling pathways linked to obesity can result in vascular endothelial dysfunction and changed levels of Nitric oxide (NO). Hyperlipidaemia may exacerbate arterial stiffness which is a precursor to atherosclerosis. In this study, we tried to evaluate the changes in levels of nitric oxide in obese individuals and its association with arterial stiffness. Objectives: To identify the association of serum levels of Nitric oxide metabolites with Body Mass Index (BMI) in apparently healthy subjects. To evaluate any correlation between serum nitric oxide metabolites, BMI and arterial stiffness in obese individuals. Result: The results showed a significant increase in systolic blood pressure (p<0.001) and no change in diastolic blood pressure and significant increase in pulse pressure(p<0.001) with increase in visceral adiposity (Waist Circumference) more than BMI. Results of Pearson correlation indicated that there is a significant small negative relationship between BMI and Serum NO levels, (r =- 0.534, p <.001). There was significant increase in Brachial ankle Pulse Wave Velocity (Ba PWV) (p=0.001) and Carotid Femoral Pulse Wave Velocity (CF PWV) (p=0.01) in obese subjects when compared to controls. Conclusion: Our study results showed that abdominal obesity more than overall obesity is more strongly associated with decreased serum NO levels and increased arterial stiffness. In obese individuals, increased arterial stiffness as reflected by increased pulse wave velocity may contribute to predicting cardiovascular disease in both genders in addition to development of hypertension.

Association of serum nitric oxide metabolite level with mortality in patients undergoing coronary angiography

BackgroundNitric oxide (NO) is a relevant molecule for vascular homeostasis. The level of serum NO metabolites (NOx), which consist of nitrite and nitrate, has been investigated as an alternative biomarker of NO production, but its clinical value has not yet been determined. Methods and results143 patients (66 ± 12 years old) were followed up after coronary catheterization. During a median (inter-quartile range) observation period of 6.13 (3.32–9.21) years, there were 20 (14 %) all-cause deaths, including 11 (8 %) cardiovascular deaths, 17 (12 %) major adverse cardiovascular events, and 17 (12 %) hospital admissions for heart failure. Median NOx level was 34.5 μmol/L (23.9–54.3). NOx was a risk factor for all-cause death [hazard ratio (HR) by unit increase, 1.010, 95 % confidence interval (CI) 1.001–1.018; p = 0.021] and heart failure (HR 1.010, CI 1.001–1.019; p = 0.029). Even after adjustment for age, sex, coronary risk factors, C-reactive protein, log-transformed brain natriuretic peptide, estimated glomerular filtration rate, and nitrate treatment, NOx was a risk factor for all-cause death (HR 1.015, CI 1.004–1.027; p = 0.008) and admission with heart failure (HR 1.018, CI 1.005–1.018, p = 0.007). ConclusionsAn increase in serum NOx level does not herald a benign clinical course but is an independent predictor of high risk of any-cause mortality and heart failure.

Potential cardioprotective influence of bupropion against CCl4-triggered cirrhotic cardiomyopathy

Bupropion, an atypical anti-depressant and smoking cessation aid, attenuates complications arising from the activation of inflammatory and oxidative pathways. In this study, the effect of bupropion on an inflammatory and oxidative condition induced by carbon tetrachloride (CCl 4 ) namely cirrhotic cardiomyopathy (CCM) was investigated in rats. CCM was induced by intraperitoneal injection of CCl 4 (0.4 g/kg, i.p.). Bupropion was treated orally at doses 30 and 60 (mg/kg, p.o.) for 8 weeks. CCl 4 treatment significantly lowered hepatic antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH) while enhanced Malondialdehyde (MDA). Elevations in serum nitric oxide (NO) metabolites nitrite/nitrate, and cardiac tumor necrosis factor alpha (TNF-α) and interleukin 1-beta (IL-1β) levels were observed. Cirrhosis also decreased contractility in response to isoproterenol (10 −10 to 10 −5 M). The spleen weight and intrasplenic pressure increased and QTc, QRS and RR intervals prolonged. Pathological damages in the liver for example focal necrosis, fibrosis and the hepatic blocking increased. On the other hand, bupropion increased GSH, CAT and SOD and lowered MDA. Bupropion reduced NO metabolites and TNF-α levels and decreased IL-1β. The cardiac contractile force improved at maximal effect (Rmax) 10 -5 M by bupropion. The intrasplenic pressure was reduced by bupropion. Bupropion reduces QTc, QRS and RR intervals and the liver tissue damages. Bupropion played a cardioprotective role reducing inflammatory and oxidative factors. It may recover the impairment of cardiac contractility and hyperdynamic condition in CCM, and this effect could be mediated at least in part by a NO-dependent mechanism.

Nitrosative stress parameters and the level of oxidized DNA bases in patients with multiple sclerosis.

Multiple sclerosis (MS) is a neurodegenerative disease with various factors affecting its etiology. Overproduction of nitric oxide and subsequent lesions of biopolymers are some of the possible causes of the disease. This study aimed to measure the most relevant nitrosative and oxidative stress biomarkers and the level of modified DNA bases in patients with MS. Each parameter was assayed in 25 patients with MS and 25 healthy controls. This study involved detecting blood plasma and serum nitric oxide metabolites by chemiluminescence detector Sievers NOA-280i, malondialdehyde (MDA) measurements with thiobarbituric acid reactive substance (TBARS) assay, detection of oxidized purines and pyrimidines with the enzyme-modified comet assay. Statistical analysis of the results was performed by one-way analysis of variance (ANOVA) and unpaired t test for the comparison of less than three data sets. DNA single-strand breaks, levels of modified purines and pyrimidines, as well as nitrite and nitrate levels in plasma and serum samples, were significantly higher in patients with MS than in healthy controls. On the contrary, MDA levels appeared to be lower in patients with MS.

Vascular and Hemostatic Alterations Associated with Pulmonary Hypertension in β-Thalassemia Hemoglobin E Patients Receiving Regular Transfusion and Iron Chelation

Background: β-thalassemia hemoglobin E (β-thal/HbE) is currently the commonest β-thalassemia disease worldwide. Pulmonary hypertension (PH) is the most common cardiovascular complication in this genotype, especially in splenectomized patients. Yet the pathogenesis of this major complication remains poorly characterized. Most of the previous reports investigated pathophysiology of PH in β-thal/HbE with inadequate transfusion. In this study we aimed to define the prevalence and comprehensively explore mechanisms of PH in β-thal/HbE patients receiving regular transfusion and iron chelation which were reported to alleviate PH. Our findings will provide deeper insights into pathogenesis and identify targets for management of persistent PH in thalassemia patients after adequate transfusion and chelation.Methods: β-thal/HbE patients who received regular transfusion ≥ 1 unit per month and any forms of iron chelation over 1 year were eligible for the study. Normal healthy subjects were used as controls. Blood sample collection and echocardiographic assessment were performed on the same days. Patients at risk for PH were defined by the tricuspid regurgitant jet velocity (TRV) ≥ 2.5 m/s.Results: There were 68 β-thal/HbE and 38 healthy controls enrolled between May and September 2015. The ages (mean ± SD) were 34.1 ± 12.6, ranging from 19-67 years, and 37.2 ± 8.6 years, ranging from 18-70 years, respectively. Among 68 β-thal/HbE, the average transfusion duration was 8.1 ± 2.2, ranging from 2.2-10.6 years, and the quantity of transfusion was 22.3 ± 9.6 units per year. The pre-transfusion hemoglobin (Hb) level was 8.1 ± 1.3 g/dL. There were 31 (45.6%) splenectomized patients. β-thal/HbE showed markedly increased erythropoiesis (growth differentiation factor, GDF15, and soluble transferrin receptor, sTfR, levels) and iron load (serum ferritin) compared to controls, all p < 0.001. Thrombin antithrombin (TAT) complex and microparticle's procoagulant activity (MPA) were significantly elevated (both p < 0.001), but total tissue factor antigen (TFAg) and microparticle-associated tissue factor activity (MPTFA) were not different from those of controls, suggesting TF-independent hypercoagulability. Serum nitric oxide metabolites (NOx) and prostaglandin E2 (PGE2) levels were significantly lower than those of controls (both p < 0.001), while soluble thrombomodulin (sTM) levels were significantly elevated (p= 0.045). Serum endothelin-1 (ET-1) and soluble p-selectin levels were not different between patients and controls. Echocardiographic profiles demonstrated preserved biventricular systolic functions in β-thal/HbE with a significant increase in TRV (p < 0.001).Among β-thal/HbE, there were 29 (42.6%; 16 non-splenectomized and 13 splenectomized) cases at risk for PH. Duration and amount of transfusion, pre-transfusion Hb, GDF15 and sTfR levels were not statistically different between PH and non-PH subgroups indicating the similar degree of erythropoiesis. Notably, β-thal/HbE with PH had a significant reduction in NOx levels (p < 0.001) but elevations in TAT, ET-1 and sTM levels compared to those without PH (p= 0.046, 0.005 and 0.026, respectively). Additionally, TRV was significantly correlated with NOx, TAT, sTM and ET-1 levels (r = -0.514, p < 0.001; r = 0.281, p= 0.004; r = 0.313, p= 0.001; and r = 0.245, p= 0.012, respectively). Serum ferritin, MPA, MPTFA, TFAg and PGE2 levels were not statistically different between PH and non-PH subgroups. Surprisingly, there were no differences in any biomarkers and echocardiographic profiles between splenectomized and non-splenectomized patients as well as no significant associations between splenectomy statuses and PH (Χ2 = 0.012, p= 0.914).We reviewed another β-thal/HbE cohort with available flow mediated dilatation (FMD) data. 9 β-thal/HbE with PH had significantly lower FMD (3.43%) compared to 18 β-thal/HbE without PH (6.37%) and 27 age-sex matched controls (9.87%; p= 0.025 and p < 0.001, respectively) indicating a greater degree of endothelial dysfunction in β-thal/HbE having PH. In addition, TRV was significantly correlated with FMD (r = -0.474, p < 0.001).Conclusions: PH is still prevalent in β-thal/HbE patients receiving long-term regular transfusion and iron chelation. In this group, PH is not associated with splenectomy statuses but correlated with NO depletion, TF-independent hypercoagulation and endothelial dysfunction. [Display omitted] DisclosuresSutcharitchan:Chulalongkorn University: Consultancy, Employment; Celgene: Research Funding.

Hypericum Perforatum Extract Modifies Serum and Tumoral Redox Status and Nitric Oxide Metabolites in Mice

Plant extracts with antioxidant efficacy and/or suppressive activity on nitric oxide (NO) production are highly being used as supplements by cancer patients. Despite very high concentrations of NO can kill malignant cells; NO can also propagates cancer growth even at supraphysiological levels. Hence, discovery of safe compounds diminishing NO production may be beneficial in reducing cancer progression. Hypericum extracts are shown to exert redox-active efficacies and to reduce NO production in non-malignant conditions; but it is not studied in terms of modifying systemic and tumoral redox status, nitrite and nitrate concentrations. In this study, we showed that Hypericum perforatum extracts significantly reduces intratumoral levels of nitrite and nitrate in solid tumors formed by Ehrlich ascites carcinoma cells. These results may suggest that Hypericum perforatum extracts may act as efficient adjuvants for malignancies which growth are highly influenced and propagated with NO. Keywords: Hypericum perforatum; total oxidant status; total antioxidant status; nitric oxide; nitrite; nitrate DOI: 10.7176/JSTR/7-05-05

Body Fat Percentage, Waist Circumference and Body Mass Index are Correlated with Nitric Oxide Levels in Young Adults with Central Obesity

Background: Central obesity stands for the corner-stone of cardio-metabolic health, while nitric oxide (NO) is a major regulator of cardiovascular function. To day, the correlation between serum NO metabolites nitrate/nitrite and the obesity components in young adults remains elusive. Thus, this current study was conducted to know the correlation between serum NO metabolites levels and body fat percentage, waist circumference (WC) as well as body mass index (BMI) in young adults with central obesity.Materials and Methods: A cross-sectional study was conducted in Riau, Indonesia, involving 79 young adults aged 18-25 years, composing of 39 and 40 subjects with and without central obesity, respectively. Anthropometric measurements were performed to assess WC and BMI. Body fat percentage was measured using bioelectrical impedance analysis and serum NO metabolites levels were assessed using Griess methods.Results: Levels of serum NO metabolites were significant higher in the subjects with central obesity (168.41±12.64 μmol/L) than that of normal subjects (70.57±44.99 μmol/L, p&lt;0.001), but the levels were no significant different between male and female subjects. Serum NO metabolites levels were strongly correlated with total body fat (r=0.618, p&lt;0.001), visceral fat (r=0.733, p&lt;0.001), subcutaneous fat (r=0.547, p&lt;0.001), WC (r=0.717, p&lt;0.001) and BMI (r=0.788, p&lt;0.001).Conclusions: For young adults in Riau, Indonesia, levels of serum NO metabolites are higher in the central obesity group than that of the normal. In this population, body fat percentage, waist circumference and body mass index are correlated with serum nitric oxide metabolites levels.Keywords: nitric oxide, body fat percentage, young adults, central obesity

Cystathionine γ-lyase promotes estrogen-stimulated uterine artery blood flow via glutathione homeostasis

During pregnancy, estrogen (E2) stimulates uterine artery blood flow (UBF) by enhancing nitric oxide (NO)-dependent vasodilation. Cystathionine γ-lyase (CSE) promotes vascular NO signaling by producing hydrogen sulfide (H2S) and by maintaining the ratio of reduced-to-oxidized intracellular glutathione (GSH/GSSG) through l-cysteine production. Because redox homeostasis can influence NO signaling, we hypothesized that CSE mediates E2 stimulation of UBF by modulating local intracellular cysteine metabolism and GSH/GSSG levels to promote redox homeostasis. Using non-pregnant ovariectomized WT and CSE-null (CSE KO) mice, we performed micro-ultrasound of mouse uterine and renal arteries to assess changes in blood flow upon exogenous E2 stimulation. We quantified serum and uterine artery NO metabolites (NOx), serum amino acids, and uterine and renal artery GSH/GSSG. WT and CSE KO mice exhibited similar baseline uterine and renal blood flow. Unlike WT, CSE KO mice did not exhibit expected E2 stimulation of UBF. Renal blood flow was E2-insensitive for both genotypes. While serum and uterine artery NOx were similar between genotypes at baseline, E2 decreased NOx in CSE KO serum. Cysteine was also lower in CSE KO serum, while citrulline and homocysteine levels were elevated. E2 and CSE deletion additively decreased GSH/GSSG in uterine arteries. In contrast, renal artery GSH/GSSG was insensitive to E2 or CSE deletion. Together, these findings suggest that CSE maintenance of uterine artery GSH/GSSG facilitates nitrergic signaling in uterine arteries and is required for normal E2 stimulation of UBF. These data have implications for pregnancy pathophysiology and the selective hormone responses of specific vascular beds.

Effect of Proton Pump Inhibitors, Vitamin E and their co- administration on heart function and Oxidative Changes in Isoprenaline Induced Myocardial Infarction in Adult Male Albino Rats

Background: Myocardial infarction (MI) continues to be associated with high morbidity and mortality worldwide. Proton Pump inhibitors (PPIs) exhibit cardioprotective effects by several mechanisms. Vitamin E possesses antioxidant properties. Aim: The present study has been designed to evaluate the combined cardioprotective effect of PPIs and vitamin E on biochemical and histopathological alteration in isoprenaline (ISO) induced myocardial infarction in rats. Methods: 30 adult Wistar albino male rats divided into 5 groups as follow: Group I: Control fed a standard diet.Group II: rats were undergoing MI by ISO. Group III: Rats were pretreated pantoprazole (1.3 mg/kg, i.o) daily for 3 weeks. Group IV: Rats were pretreated with vitamin E (100 IU/kg i.o) daily for 3 weeks. Group V: Rats were given both pantoprazole (1.3 mg/kg, i.o) and vitamin E (100 IU/kg bw, i.p) daily. On 22thand 23th day, rats in groups (II-V) were injection i.p with ISO (100mg/kg bw for successive two days). Results: ISO induced infarction in rats resulted in a significant elevation in ST segment height, T – wave voltage, Heart rate (HR), serum lactate dehydrogenase (LDH), malondialdehyde (MDA) and nitric oxide metabolites (NO), whereas it caused a significant (P < 0.05) decrease in systolic blood pressure(SBP) and serum superoxide dismutase (SOD) when compared with the control group. Moreover, interventions with PPIs supplementation and/or vitamin E significantly reversed the aforementioned parameters with better impact of their combination. Conclusion: PPIs combined with vitamin E exert potential protective effect against MI through lowering calcium overload and enhancement of antioxidant activity.

Acute (-)-Epicatechin Consumption: Effects on Local Vasodilation Following Resistance Exercise and High-Intensity Exercise Performance.

(-)-Epicatechin is a polyphenol previously shown to enhance vascular health. The purposes of the current studies were to determine the effect of acute (-)-epicatechin supplementation on local vasodilation in conjunction with resistance exercise (study 1) and on high-intensity exercise performance (study 2). For study 1, 11 men participated in two resistance exercise sessions, where they performed three sets of barbell curls while consuming 200 mg of 98% pure (-)-epicatechin or placebo. Measurements of total serum nitrate/nitrite and brachial artery diameter were acquired at baseline (pre-supplement), 90 min after supplement consumption (post-supplement), immediately post-exercise (post-exercise), and 30 min post-exercise (30 min post-exercise). For serum nitric oxide metabolites, no significant interaction between supplement and time nor significant main effect of time was observed (p = 0.38 and p = 0.20; respectively). For brachial artery diameter, no significant interaction between supplement and time was observed (p = 0.24). A significant main effect of time was observed for brachial artery diameter (p < 0.01) with post-exercise brachial artery diameter significantly greater diameter than all other time points (all p < 0.01). For study 2, six women and five men completed the 15.5 CrossFit® Open Workout three times. A familiarization session was performed first where the workout was performed without the consumption of a supplement. In a randomized, balanced fashion, 100 mg of 98% pure (-)-epicatechin or cellulose (placebo) was consumed two times per day for two days before testing sessions two and three. On the day of testing sessions two and three, 60 to 90 min before completing the workout, 200 mg of the assigned supplement was ingested with water. No significant difference was observed for time to complete the workout between testing sessions (p = 0.49). In conclusion, under the conditions of the current studies, acute (-)-epicatechin supplementation did not augment vasodilation in combination with resistance exercise, nor did it increase exercise performance in humans.

The effect of intense physical exertion on the biochemical parameters of antioxidant protection systems and nitric oxide in swimming athletes

Introduction. Intense physical activity leads to a violation of homeostasis, which is supported by a balanced work of the body’s defense systems against oxidative stress, in particular, antioxidant, thiol disulfide and nitric oxide system. The study of these indicators will improve the mechanisms of adaptation of the human body to physical activity.The aim of the study was to identify the features of changes in antioxidant protection systems and nitric oxide during intense physical activity in athletes-swimmers.Materials and methods. Blood of athletes-swimmers (n=30, age 23,0±2,5 years) in the conditions of intensive physical loadings is investigated. Oxidative stress, total serum antioxidant capacity, glutathione levels and nitric oxide metabolites were studied by photometric biochemical methods.Results. In 73.3% of athletes after intense physical activity remained elevated levels of oxidized glutathione, 30% had a high level of oxidative stress, 26.7% of the level of antioxidant capacity of serum is low, 73.3% was reduced relative to the initial level of the concentration of nitric oxide metabolites.Conclusion. Intense physical activity leads to oxidative stress and disturbances in the antioxidant system of the athlete’s body. With increasing load, the degree of violations increases. The level of oxidative stress increases, the total antioxidant capacity of serum decreases, the functioning of glutathione is disrupted. Integral indicators of oxidative stress, as well as glutathione fractions can be recommended for monitoring the state of oxidative stress.

Serum nitric oxide metabolites and hard clinical endpoints: a population-based prospective study

Objective. Limited data are available regarding prognostic value of nitric oxide metabolites (NOx) for clinical hard end points. In this study, we defined optimum cut-off values of serum NOx for predicting all-cause and cardiovascular disease (CVD) mortality events and prospectively investigated their hazards in the presence of traditional risk factors. Design. Serum NOx concentrations were measured at baseline (2006–2008) and 3520 adult men and women were followed during 7.7 years for all-cause and cardiovascular disease (CVD) mortality. To determine the optimal cut-off points of serum NOx, the receiver operator characteristic (ROC) curve analysis was used. Multivariate Cox proportional hazard models were used to estimate the hazard ratios (HRs) with 95% confidence intervals (95% CIs) of all-cause and CVD mortality below and above the defined optimal cut-off points of serum NOx. Results. Mean age of participants was 44.5 ± 16.0 years at baseline and 40.2% were male. Median (inter-quartile range) of serum NOx levels was 25.0 µmol/L (19.0–37.0), at baseline. The optimal cut-off points of serum NOx levels for predicting CVD and all-cause mortality were 30.5 and 32.5 µmol/L, respectively. In the presence of age, sex, body mass index, smoking, type 2 diabetes, hypertension, and history of CVD, a significant increased risk of CVD mortality (HR = 1.98, 95% CI = 1.10–3.58) and all-cause mortality (HR = 1.52, 95% CI = 1.05–2.21) was observed for serum NOx values higher than their cut-offs. Conclusion. Serum NOx level may be predictor of CVD mortality and death, in general populations.

Reactive Species Interactome Alterations in Oocyte Donation Pregnancies in the Absence and Presence of Pre-Eclampsia.

In pregnancy, maternal physiology is subject to considerable adaptations, including alterations in cardiovascular and metabolic function as well as development of immunological tolerance towards the fetus. In an oocyte donation pregnancy, the fetus is fully allogeneic towards the mother, since it carries both oocyte donor antigens and paternal antigens. Therefore, oocyte donation pregnancies result in an immunologically challenging pregnancy, which is reflected by a higher-than-normal risk to develop pre-eclampsia. Based on the allogeneic conditions in oocyte donation pregnancies, we hypothesized that this situation may translate into alterations in concentration of stable readouts of constituents of the reactive species interactome (RSI) compared to normal pregnancies, especially serum free thiols, nitric oxide (NO) and hydrogen sulfide (H2S) related metabolites. Indeed, total free thiol levels and nitrite (NO2−) concentrations were significantly lower whereas protein-bound NO and sulfate (SO42−) concentrations were significantly higher in both oocyte donation and naturally conceived pregnancies complicated by pre-eclampsia. The increased concentrations of nitrite observed in uncomplicated oocyte donation pregnancies suggest that endothelial NO production is compensatorily enhanced to lower vascular tone. More research is warranted on the role of the RSI and bioenergetic status in uncomplicated oocyte donation pregnancies and oocyte donation pregnancies complicated by pre-eclampsia.

026 Testosterone deficiency causes endothelial dysfunction via elevation of asymmetric dimethylarginine (ADMA) and oxidative stress in castrated rats

Testosterone is thought to mediate the erectile function by producing an adequate nitric oxide (NO), and therefore testosterone deficiency results in erectile dysfunction via reduced NO bioavailability. However, the mechanisms underlying endothelial dysfunction in testosterone deficiency remain unclear. We investigated the mechanism of endothelial dysfunction in castrated rats by focusing on the relationship between testosterone deficiency and asymmetric dimethylarginine (ADMA), an endogenous NO synthase (NOS) inhibitor. Male rats were categorised into the following groups: castrated (Cast), castrated with testosterone (3 mg/kg/day) (Cast+T), and sham (Sham). Erectile function using ICP measurements, endothelial function using isometric tension, ADMA levels using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) and oxidative stress (NADPH oxidase and p22phox), and inflammatory biomarker expression (IL-6, NF-κB) and ADMA generated (DDAH) were assessed 4 weeks postoperatively. Oxidative stress analysis was also performed by quantifying the 8-OHdG levels of DNA. The ICP/MAP ratios were 0.61 ± 0.03 in Sham, 0.26 ± 0.04 in Cast (p < 0.01 vs. Sham), and 0.56 ± 0.06 in Cast+T (p < 0.01 vs. Cast). Relaxation responses induced by acetylcholine were decreased in Cast compared to Sham and Cast+T (p < 0.05). Cast rats also had significantly lower serum NO metabolite (NOx) levels than Sham counterparts (Sham, 4.20 ± 0.54 μmol/L; Cast, 2.87 ± 0.28 μmol/L; p < 0.01). However, the Cast+T and Sham rats had similar serum NOx levels (Cast+T, 4.39 ± 0.77 μmol/L; p > 0.05). Serum ADMA levels were significantly higher in Cast (297.3 ± 22.9 ng/mL) than in Sham (200.8 ± 9.4 ng/mL) or Cast+T (198.1 ± 27.7 ng/mL; both p < 0.05). Oxidative stress and inflammatory marker messenger RNA expression were significantly higher in Cast than in Sham and Cast+T (p < 0.05). Expression of the ADMA generated biomarker was significantly higher in Cast than in Sham or Cast+T (both, p < 0.01). The 8-OHdG levels were significantly higher in Cast (18.7 ± 0.9 ng/DNA 1 ng) than in Sham (13.9 ± 1.4 ng/DNA 1 ng) or Cast+T (13.3 ± 1.7 ng/DNA; both p < 0.05).

Antibodies against HDL Components in Ischaemic Stroke and Coronary Artery Disease.

Quantitative and qualitative defects of high-density lipoprotein (HDL) are important in atherogenesis. In this study, we investigated whether antibodies against HDL components had additional value to conventional cardiovascular risk factors for the diagnosis of ischaemic stroke (IS) and coronary artery disease (CAD). Cross-sectional study was conducted on 53 patients with IS, 51 with CAD and 55 healthy controls, and in vitro studies to validate findings of the clinical study. We determined serum immunoglobulin G (IgG) antibodies against HDL (aHDL), apolipoproteins (aApoA-I, aApoA-II and aApoC-I) and paraoxonase-1 (aPON1) as well as PON1 activity (PON1a), total antioxidant capacity and biomarkers of endothelial activation (serum nitric oxide metabolites, 3-nitrotyrosine, VCAM-1 and ICAM-1); in vitro assays tested the capacity of IgG aHDL purified from high titer patients to inhibit PON1a and to reverse protective effect of HDL on endothelial cells. IgG aHDL, aApoA-I and aPON1 were higher in IS and CAD than controls (p < 0.001), predicted negatively PON1a and positively VCAM-1 and ICAM-1. By adding IgG aHDL and aApoA-I to a traditional cardiovascular risk factors model for IS and by adding IgG aHDL in a similar model for CAD, we obtained better discrimination of IS and CAD from healthy controls. IgG aHDL purified from IS and CAD inhibited PON1a by 38% (p < 0.01) and abrogated the protective effect of HDL on VCAM-1 expression by 126% compared with non-specific human IgG (p < 0.001). IgG against HDL components interfere with the antioxidant and anti-inflammatory properties of HDL and may represent novel biomarkers for vascular disease that need to be investigated in prospective studies.

The protective role of oestradiol against silent myocardial ischemia and hypertension risk in South African men: The SABPA study

BackgroundOestradiol has a protective effect on coronary artery health in women but the effect it has on men, is controversial. A translational approach was followed to assess whether sex hormone levels are associated with silent myocardial ischemia (SMI) and hypertension risk over a 3year period. MethodsParticipants included 89 Black and 91 White men (aged 21–63years) participating in both phases of the Sympathetic activity and Ambulatory Blood Pressure in Africans prospective study. Fasting blood samples, ambulatory blood pressure and 2-lead ECG recordings were obtained. ResultsNo difference in the levels of the various baseline serum T fractions between the two ethnic groups occurred. Oestradiol of the Black men increased by 54.2% compared to a decrease of 24.1% in the White men. Changes in total oestradiol (adjusted R2=0.33, β=−0.31, p=0.023) and free oestradiol (adjusted R2=0.34, β=−0.33, p=0.019) were inversely associated with changes in SMI in the Black men but not in White men. Baseline serum nitric oxide metabolites were inversely associated with ΔSMI in the Blacks only (adjusted R2=0.33, β=−0.28, p=0.047). Chronic SMI was associated with 24h hypertension in Blacks [cut point 1.5 events: Area under the curve 0.71 (95% CI: 0.60, 0.82); p=0.006; with sensitivity/specificity 44%/94%]. ConclusionsChronic SMI events facilitated future ischemic heart disease in Black men. Up-regulated free oestradiol seems to be involved in the protection of the heart against SMI and hypertension risk in Black but not in White men. A similar protective role for testosterone could however not be shown.

High-sulforaphane broccoli sprout powder reduces serum nitric oxide metabolites in Helicobacter pylori infected patients

Pathological over production of nitric oxide (NO), induced by Helicobacter pylori, has been known as a risk factor for development of gastritis and gastric cancer. The current study investigated the effect of high-sulforaphane (SFN) broccoli sprouts powder on serum NO metabolites in H. pylori infected patients. Eighty-six patients with positive H. pylori stool antigen test (HpSAg) were randomized to receive one of the three following regimens: Standard triple therapy (STT) for 14days, 6g/d broccoli sprouts powder (BSP) for 28days, and combination of these as STT (for 14days)+BSP (for 28days). Fasting serum NO metabolites were assessed at baseline and again after treatment. There was a significant decrease in serum NOx levels in BSP (25.2 vs. 51.6μmol/L, P<0.001) and STT+BSP (31.9vs. 44.3, μmol/L, P<0.05) groups after intervention. High-SFN present in broccoli sprouts, may attenuate undesirable overproduction of NO in H. pylori infected patients.

Mediterranean tomato-based sofrito protects against vascular alterations in obese Zucker rats by preserving NO bioavailability.

Sofrito, a key component of the Mediterranean diet, provides nutritional interest due to its high content in bioactive compounds from tomato and olive oil, and especially to the lipid matrix in which these compounds are found. In this study, the potential beneficial effects of dietary intake of sofrito on obesity-related vascular alterations were explored in obese Zucker rats. Obese and lean rats were fed a control diet supplemented or not with 2% w/w sofrito for 8 weeks. Vascular function was evaluated in aorta in organ baths. Dihydroethidium staining and immunofluorescence was used to determine aortic superoxide and peroxynitrite production, respectively. Despite food and caloric intake was higher in sofrito-fed obese rats, no differences were appreciated on body weight compared to control rats. Sofrito attenuated phenylephrine-induced vasoconstriction. This effect was associated with preservation of nitric oxide on vasoconstriction and normalization of serum nitric oxide metabolites, vascular inducible nitric oxide synthase and vascular superoxide and peroxynitrite levels. This is the first evidence of tomato-based sofrito protection against vascular alterations that could precede major cardiometabolic complications in obesity. These results contribute to explain the therapeutic properties of the Mediterranean diet in obesity-related disorders. Therefore, sofrito is an attractive dietary approach against vascular alterations in obesity.

Serum nitrite and nitrate levels, NOx, can predict cardiovascular mortality in the elderly in a 3-year follow-up study.

Nitric oxide (NO) is an important functional regulator that contributes to progression of various cardiovascular diseases. We studied associations between nitric oxide metabolites, nitrite and nitrate (NOx), and cardiovascular mortality in a prospective 3-year follow-up cohort study in 1,869 elderly patients aged over 55 years. The Cox proportional hazard regression model was adjusted for multiple factors including sex, age, risk corresponding to preexisting cardiovascular conditions, and serum inflammatory markers (C-reactive protein, interleukin-6, fibrinogen, and leucocytes count). During the follow-up period, there were a total of 348 deaths including 216 deaths unrelated to cardiovascular events and 132 cardiovascular deaths. Cox regression adjusted for factors related to cardiovascular disease risks and inflammatory markers showed a significant association between high levels of serum nitric oxide metabolites, NOx, and increased cardiovascular mortality (hazard ratio 2.21; 95% confidence interval 1.13-4.31) but there was no association with non-cardiovascular mortality. Analysis of adjusted hazard ratios demonstrates that association of serum nitric oxide metabolites with cardiovascular mortality was independent of levels of inflammatory markers. Thus, elevated concentrations of serum nitric oxide metabolites are a predictor of cardiovascular mortality and may be used as an integral marker of cardiovascular death. © 2016 BioFactors, 43(1):82-89, 2017.