NO Metabolites Research Articles

Алельний поліморфізм гена eNOS у дітей, які страждають від бронхіальної астми, за еозинофільного та пауцигранулоцитарного субтипу запалення бронхів

Метою роботи було вивчити вплив алельного поліморфізму гена eNOS, що кодує активність ендотеліальної NO-синтази та синтез монооксиду нітрогену в дихальних шляхах, на окремі клінічно-параклінічні показники бронхіальної астми в дітей шкільного віку за еозинофільного і пауцигранулоцитарного запального фенотипу. Обстежені 22 хворі на бронхіальну астму з еозинофільним характером запалення дихальних шляхів та 15 пацієнтів — із пауцигранулоцитарним. Проведено імунологічні, спірометричні дослідження, генотипування ендотеліальної NOS.Тяжкість бронхіальної астми у хворих із різним типом запалення бронхів суттєво не залежить від алельного поліморфізму гена eNOS. Відсутність мутацій гена eNOS у вигляді генотипу GG виявилася характернішою для хворих із пауцигранулоцитарним характером запалення бронхів, алельний поліморфізм GT/TT — для дітей з еозинофільним запаленням. За наявності алельного поліморфізму гена eNOS за генотипу GT/TT дітям із пауцигранулоцитарним характером запалення бронхів були притаманні частіші клінічні прояви атопічного дерматиту й алергічного риніту, більший індекс лабільності бронхів та нижча концентрація метаболітів NO в конденсаті повітря, що видихається.

Влияние полиморфизмов 894G/T и Т786С гена эндотелиальной синтазы оксида азота на уровень продуктов их экспрессии — eNOS и NOу детей с артериальной гипертензией

The purpose — to study the effect of the polymorphic variants 894G/T and T786C of NOS3 gene of the endothelial nitric oxide synthase gene on the levels of their expression products — eNOS and NO in children with arterial hypertension. Material and methods. We examined 111 children, including 51 patients with arterial hypertension, 30 patients with high-normal blood pressure and 30 healthy children. The polymorphism of the study genes was studied using a real-time polymerase chain reaction. Determination of plasma concentrations of eNOS was performed with enzyme immunoassay. NO metabolites, nitrateandnitrite (NOx) production were determined using the Griess reaction. Results. Among the children of the Grodno region, the homozygous GG genotype and the G-allele of the polymorphic locus 894G/T of the NOS3 gene and the heterozygous TC genotype and the T-allele of the T786C polymorphic variant of the NOS3 gene predominate. The presence of the T allele 894G/T of the NOS3 gene in children with arterial hypertension is associated with a decrease eNOS expression and NOx levels compared with T allele carriers among healthy children. Heterozygous genotype 786TC and allele C of T786C polymorphism of the NOS3 gene in children with arterial hypertension are characterized by a low level of NOx compared with healthy children.

Study of possible sex features of ramipril and candesartan treatment under experimental arterial hypertension in rats

The article presents the results of a preclinical study of ramipril and candesartan in an experimental group of hypertensive rats of different sexes. Antihypertensive therapy was performed for 21 days. The drugs were administered daily in moderate therapeutic doses calculated for rats using the coefficient of species sensitivity. It was found that the course of experimental hypertension has gender differences, and in males, according to blood pressure, the level of NO metabolites is more pronounced. The use of ramipril from the group of ACE inhibitors and candesartan from the ARBs group in experimental hypertension in rats has gender differences. Ramipril is likely to be more effective in normalizing blood pressure and endothelial function in males than females. The use of candesartan did not show significant gender differences, but there was a tendency for females to be slightly more effective than males. Established gender differences in hypertension pharmacotherapy should be considered to optimize treatment.

Monooxygenase System and NO Metabolism in Liver Microsomes of Rats with Toxic Hepatitis and the Effect of Sesquiterpene Lactones.

We analyzed changes in activities of enzymes of phases I and II of xenobiotic biotransformation and parameters of NO metabolism in liver microsomes of rats with toxic CCl4-induced hepatitis after a 14-day course of sesquiterpene lactones from Artemisia leucodes (10 mg/kg). It was found that toxic hepatitis was associated with significant inhibition of NADPH-cytochrome c-reductase, benzo(a)pyrene hydroxylase, and NADPH-diaphorase, reduced cytochrome P-450 content, and enhanced induction of nitrate/nitrite reductase with accumulation of NO metabolites in the liver. Administration of sesquiterpene lactones stimulated activity of the studied components of the cytochrome P-450 system and promoted recovery of the NOergic system components; the effects were most pronounced in 7 and 14 days after treatment.

Метаболиты оксида азота при развитии осложнений после открытых реконструктивных вмешательств у пациентов с периферическим атеросклерозом

BACKGROUND: Assessing the severity of endothelial dysfunction (ED) and making a prognosis after open reconstructive interventions in patients with peripheral atherosclerosis is complicated due to a limited number of conventional routine methods, including laboratory ones, available for establishing associations between biochemical markers and disease outcomes. AIM: This work is dedicated to the evaluation of nitric oxide (II) metabolites (nitrates and nitrites) in patients with complications following open bypass procedures on the lower extremity arteries using synthetic grafts in order to assess the severity of endothelial dysfunction and its negative sequalae. MATERIALS AND METHODS: The study involved 60 subjects with stage IIb–III chronic lower limb ischemia according to A. V. Pokrovsky–Fontaine classification (categories 3–5 Rutherford) due to atherosclerotic peripheral artery disease. Median age of the subjects was 65 (60–67); the majority of the patients were male (51 (85%). Median value of ankle-brachial index at baseline was 0.32 (0.19–0.42). All participants underwent open bypass grafting procedures using synthetic vascular grafts. Nitric (II) oxide (NO) metabolites level (nitrites and nitrates) was measured before the intervention and three months afterwards by spectrophotocolorimetry using an ELISA analyzer Stat Fax 3200 (Awareness Techonology, Inc., USA) and Griess reagent. The subjects were followed up for a year to determine the rate of development of complications such as restenosis, graft thrombosis, limb loss (major amputation), lethal outcomes, as well as disease progression, myocardial infarction, oncology, and stroke. RESULTS: Performance of a reconstructive procedure on lower extremity arteries was followed by a decrease in NO metabolites level from initial median 76.3 mcmol/ml (48–100.7) to 52.4 mcmol/ml (36.1–93.8) at three months after the intervention (р = 0.015). There was a positive correlation between the NO metabolites level at baseline (0 months) and follow-up visit (3 months) (r = +0.573). Complications within one year after bypass procedures were detected in 66.64% subjects. Baseline level of NO metabolites in patients who required an amputation within one year after the procedure was markedly elevated and reached 116.3 mcmol/ml (90–130.5) (p = 0.025); development of restenosis and lethal outcomes within one year were associated with initially low NO metabolites levels, 35.6 mcmol/ml (p = 0.036) and 33 mcmol/ml (30–36), accordingly (р = 0.043). CONCLUSIONS: Both markedly high and low levels of nitric oxide metabolites (nitrates and nitrites) levels are associated with development of severe complications after open reconstructive procedures in patients with peripheral atherosclerosis. Quantitative determination of the NO metabolites level in serum is a relatively easy and reliable method allowing for the determination of the severity of endothelial dysfunction and its sequalae in subjects after open bypass reconstructive procedures on lower extremity arteries.

Complex correction of metabolic changes and endothelial dysfunction in patients with ischemic heart disease and eff ort angina of functional class II

Objective: to study the role of free radical processes, disturbances in nitric oxide homeostasis and cholesterol metabolism in the formation of endothelial disorders in patients with chronic heart disease (CHD) with eff ort angina pectoris functional class II (FC); to substantiate the complex correction of disorders. Material and methods. The study included 75 patients with coronary artery disease and eff ort angina FC II at the age of 50.1 ± 10 years old in the course of a year. The patients were divided into 4 groups: 1st group — control, 2nd group — data obtained on the background of basic therapy; 3rd group — basic therapy + atorvastatin; 4th group — a combination of basic therapy with atorvastatin and coenzyme Q10. In all patients, the intensity of lipid peroxidation, the activity of the antioxidant system, the content of NO metabolites and cholesterol metabolism were determined. To assess the functional state of the heart, an ECG study, daily ECG monitoring with the use of the Microvit MT-101 Holter system and blood pressure were performed. Results. The data showed the development of oxidative stress, inhibition of AOD cells and a decrease in the NO metabolites content and impairment of its bioavailability due to atherogenic changes in the vascular wall. Metabolic changes were accompanied by hypertension, ECG changes and anginal attacks. Combined therapy with atorvastatin and coenzyme Q10 against the background of basic therapy caused a positive dynamics of metabolic and functional disorders. Conclusion. The results of complex therapy with an inhibitor of HMG-CoA reductase and coenzyme Q10 proved the effi cacy of the infl uence on oxidation-reduction reactions, endothelial function, total cholesterol, LDL cholesterol, HDL cholesterol and functional parameters of the heart.

Роль розладів функціонального стану ендотелію в розвитку і прогресуванні діабетичної периферичної симетричної полінейропатії залежно від генетичних чинників

Мета. Оцінка показників функціонального статусу ендотелію у хворих на діабетичну периферичну симетричну полінейропатію (ДПСП) внаслідок цукрового діабету (ЦД) 2­го типу залежно від поліморфізму ендотеліального гена NO­синтази (eNOS). Матеріали та методи. Під спостереженням перебувало 110 хворих на ДПСП на тлі ЦД 2­го типу, які сформували основну групу. Середній вік пацієнтів становив 54,2 року (від 38 до 72 років). Розподіл пацієнтів здійснювався за тяжкістю ДПСП: першу групу становили 32 (29,1 %) пацієнти з початковими проявами ДПСП; друга група включала 58 (52,7 %) пацієнтів із помірним ступенем; третя група — 20 (18,2 %) пацієнтів із вираженим ступенем ДПСП. Усім пацієнтам проведено неврологічний огляд за шкалою ней­ропатичного симптоматичного і нейропатичного функціонального підрахунку. Функціональний стан ендотелію досліджували за вмістом стійких метаболітів оксиду азоту (NO) в крові й числом циркулюючих ендотеліальних клітин у крові. Поліморфізм G894T в гені eNOS виявлено за допомогою полімеразної ланцюгової реакції. Результати. Згідно з отриманими даними, у більшості пацієнтів (78,5 %) відзначалося зменшення кількості NO2–­NO3–. Число десквамованих ендотеліальних клітин було вірогідно збільшене в усіх досліджених пацієнтів порівняно з контрольною групою. При порівняльній оцінці ендотеліальних функціональних параметрів залежно від поліморфізму G894T в гені eNOS встановлено, що у хворих із гомозиготним генотипом для рідкісної T алелі спостерігалося вірогідне зниження вмісту NO2–­NO3– — у 43,6 % (p < 0,05) порівняно з контрольною групою. Висновки. Встановлені вірогідні порушення функції ендотелію у хворих із помірним і вираженим ступенем діабетичної периферичної симетричної полінейропатії на тлі ЦД 2­го типу. Результати дослідження підтвердили ймовірний вплив поліморфізму G894T в гені eNOS на утворення фенотипу, що обумовлює схильнiсть до розвитку мікроангіопатій.

Effective Cytotoxicity of Dendritic Cells against Established T Cell Lymphomas in Mice.

T cell lymphomas arise in mice that constitutively express a single TCR in the absence of NK cells. Upon TCR engagement these lymphomas are able to corrupt tumor surveillance by decreasing NK cell numbers. In this study, we investigate the outcome of interactions between these T cell lymphomas and dendritic cells. Bone marrow–derived dendritic cells mediated effective killing of T cell lymphomas after activation with IFN-γ and TLR ligands in culture. This cytotoxicity was independent of MHC compatibility. Cell lysis was reduced by the presence of the peroxynitrite inhibitors FeTTPS and L-NMMA, whereas inhibitors of apoptosis, death receptors, and degranulation were without effect, suggesting NO metabolites as the main mediators. When injected together with GM-CSF and R848 into lymphoma-bearing mice, in vitro–expanded bone marrow–derived dendritic cells caused significant survival increases. These data show that dendritic cell adaptive immunotherapy can be used as treatment against T cell lymphomas in mice.

Effect of Nitinol on Metabolic and Coagulation Activity of Endothelial Cells Culture

We studied the effect of nitinol, the most prevalent material for endovascular stents, on metabolic and coagulation activity of a primary culture of human umbilical vein endothelial cells (HUVEC). Metabolic activity was evaluated using MTS-test and by the level of stable NO metabolites in the conditioned medium, coagulation activity was assessed by activity of von Willebrand factor (vWF) and levels of plasminogen activator inhibitor-1 (PAI-1) and soluble endothelial protein C receptors (sEPCR). Exposure to nitinol reduced metabolic activity of the cell culture by 11.1% in comparison with the control (p<0.001). Although absolute activity of vWF and absolute level of sEPCR were elevated, incubation with nitinol did not lead to a statistically significant elevation of these parameters in comparison with the control, which can indicate the absence of substantial hypercoagulation effects of nitinol.

Association Between Serum Nitric Oxide Level and Changes in Thyroid Function Test in a Population-based Study: Tehran Thyroid Study Participants (TTS).

BackgroundNitric oxide (NO) plays a key role in thyroid function regulation through the inhibition of iodide (I) uptake at the thyroidal sodium-iodide symporter (NIS) and impacts on the thyroid vascularity and blood flow.ObjectivesThis study aimed to evaluate the association between serum NO metabolites (NOx) and thyroid-stimulating hormone (TSH), free thyroxin (FT4), and anti-thyroid peroxidase (TPOAb) changes. Also, it aimed at evaluating the correlation between serum NOx and the incidence of clinical hypothyroidism, characterized by elevated TSH level and decreased FT4 concentration, and subclinical hypothyroidism, characterized by mildly elevated TSH level despite FT4 concentration within the normal range, over three years of follow-up.MethodsThis study included 1,137 participants of the Tehran Thyroid study (TTS), aged > 20 years old, for whom data on serum TSH, FT4, and TPOAb in the third and fourth phases, and serum NOx in the third phase were available. Changes in TSH (ΔTSH), FT4 (ΔFT4), and TPOAb (ΔTPO) between the third and fourth phases were calculated, and the associations between serum NOx and ΔTSH, ΔFT4, and ΔTPOAb were assessed after multivariable adjustment using linear regression analysis.ResultsNo significant association was found between serum NOx and ΔTSH, ΔFT4, and ΔTPOAb after the multivariable adjustment; neither was any observed in TPOAb split groups after multivariable adjustment. No significant association was found between serum NOx tertiles and clinical and subclinical hypothyroidism incidence in the fourth phase of TTS.ConclusionsThere was no association between serum NOx levels and changes in TSH, FT4, and TPOAb and clinical and subclinical hypothyroidism incidence.

The Janus Kinase Inhibitor Ruxolitinib Prevents Terminal Shock in a Mouse Model of Arenavirus Hemorrhagic Fever.

Arenaviruses such as Lassa virus cause arenavirus hemorrhagic fever (AVHF), but protective vaccines and effective antiviral therapy remain unmet medical needs. Our prior work has revealed that inducible nitric oxide synthase (iNOS) induction by IFN-γ represents a key pathway to microvascular leak and terminal shock in AVHF. Here we hypothesized that Ruxolitinib, an FDA-approved JAK inhibitor known to prevent IFN-γ signaling, could be repurposed for host-directed therapy in AVHF. We tested the efficacy of Ruxolitinib in MHC-humanized (HHD) mice, which develop Lassa fever-like disease upon infection with the monkey-pathogenic lymphocytic choriomeningitis virus strain WE. Anti-TNF antibody therapy was tested as an alternative strategy owing to its expected effect on macrophage activation. Ruxolitinib but not anti-TNF antibody prevented hypothermia and terminal disease as well as pleural effusions and skin edema, which served as readouts of microvascular leak. As expected, neither treatment influenced viral loads. Intriguingly, however, and despite its potent disease-modifying activity, Ruxolitinib did not measurably interfere with iNOS expression or systemic NO metabolite levels. These findings suggest that the FDA-approved JAK-inhibitor Ruxolitinib has potential in the treatment of AVHF. Moreover, our observations indicate that besides IFN-γ-induced iNOS additional druggable pathways contribute essentially to AVHF and are amenable to host-directed therapy.

Ambulatory Blood Pressure Monitoring and Endothelial Dysfunction in Hypertensive Patients with Diabetes Mellitus Type 2

Aim: Diabetic hypertensive patients have pronounced changes in ambulatory blood pressure profile and endothelial function. But the correlation between the parameters of ambulatory blood pressure monitoring (ABPM) and endothelial dysfunction in diabetic hypertensive patients have not been fully clarified. We studied ABP and endothelial function in a group of diabetic hypertensive patients. Methods: Patients with a glomerular filtration rate (GFR) of less than 30 mL/min per 1.73 m(2) were excluded. 120 patients were included into the research. Of these, the first (basic) group made up diabetic hypertensive patients in which there were 34 males and 26 females, the mean age was 56.1±1.3 years, the duration of arterial hypertension (AH) was 12.3±2.1 years and the duration of type 2 diabetes mellitus (DM2) was 4.4±0,7 years. The second (control) group made up 60 non-diabetic hypertensive patients in which there were 27 males and 33 females, the mean age was 55.2±1.2 year and duration of AH was 11.1±0.9 years. The patients in both groups were similar in age, duration of AH. Results:The analysis of the results of the 24-hour ABPM revealed that the number of patients with increased 24 hour systolic blood pressure (SBP) and diastolic blood pressure (DBP) variability was more among diabetic hypertensive patients than in non-diabetic hypertensive patients (76.7 % versus 21.1 and 70.0 % versus 22.5 %, respectively, p <0,05). There were not any significant changes in pulse rate, SBP and DBP. The amount of non-dipper and night-peaker patients was significantly higher in the basic group than in the control one (60.0 % versus 25.4 %, respectively, p <0,05). It was established that the number of patients with DBP daily value <10 was more significant in diabetic hypertensive patients versus non- diabetic hypertensive patients (33.3 % versus 18.2 %, respectively). We also determined nitric oxide metabolites concentration (nitrites and nitrates (NO)) and endothelin (ET-1) in serum and in 24 h-urine collection to assess endothelial function. So, the concentration of ET-1 in serum was significantly higher in diabetic hypertensive patients compared with non-diabetic hypertensive patients (2.49±0.01 pg/ml versus 1.5±0.07 pg/ml, respectively, p <0,05). NO metabolites concentration in serum and urine was significantly lower in the basic group than in the control group (12.7±1.5 uM versus 19,9±1,8 uM and 428.2±27.9 uM versus 792.1±39.4 uM, respectively, p <0,05). The direct association between SBP, DBP and ET-1 in urine were determined in diabetic hypertensive patients (r = 0.7, r = 0.99, respectively, p < 0.001). The correlation between daily index of SBP and ET-1 in urine (r = -0.58, p < 0.001), daily index of DBP and ET-1 in serum (r = -0.47, p < 0.001) were established in the basic group. Conclusion: The correlation between the parameters of ABPM and endothelial dysfunction in diabetic hypertensive patients were established in this study.

The role of recovered thiols in venous endothel adaptation in case of autovenous reconstruction of lower limb arteries

Purpose. To evaluate the role of thiol status and its correlative relationship with the level of nitric oxide metabolites and vascular endothelial growth factor A (VEGF-A) in the blood plasma of patients with critical lower limb ischemia (CLI) after autovenous reconstructions of femoropopliteal segment’s arteries in the setting of venous endothelium of the arterial bed. Materials and methods . 54 patients with critical lower limb ischemia had been examined and divided into groups: synthetic prosthesis, in situ autovenous bypass procedure and reversed vein autovenous bypass procedure. Peripheral venous blood was taken on the 1 st and 10th days, and in 1, 3 and 6 months after the operation. Nitric oxide metabolites level was examined with photocolorimetric method by reaction with Griess reagent on a microplate analyzer (Awareness Technology, USA). VEGF-A number estimation was done by ELISA test (PersonalLab, Italy) with the use of Human VEGF-A Platinum ELISA. The level of thiol (SH-) groups was estimated with the use of Ellman’s reagent (SERVA, Germany) on spectrophotometer (Saint-Petersburg, Russian Federation). Results. The concentration of VEGF-A and the level of SH-groups increase on the 10th day and after 1 month in the group of patients operated on using a synthetic prosthesis. The level of NO metabolites, the concentration of VEGF-A, and the content of SH-groups increase statistically significantly and then decrease to the initial values in the group of patients operated on by reversed vein autovenous bypass procedure. In the group of patients operated on by the in situ method, the level of nitric oxide metabolites increases, the concentration of VEGF-A increases on the 10th day, the level of SH-groups increases, and a positive correlation was found between the content of SHgroups and the concentration of VEGF-A. Conclusion . NO metabolites contribute to the build-up of SH groups and VEGF-A in patients operated by the “reversed vein” method, and in patients in the in situ group, the concentration of VEGF-A and the level of SH groups are not affected, which may be of clinical importance when prescribing NO donors. The revealed patterns of change in the level of recovered thiols, nitrogen oxide metabolites, VEGF-A in combination with analysis of early and late postoperative complications make it possible to conclude the advantage of autovenous reconstruction of the femoropopliteal segment due to functional adaptation of the venous endothelium compared to the group of patients, operated on by the method of “synthetic prosthesis”. Method in situ on biochemical and angiological indicators proved to be more favorable in terms of the clinical course, than the “reversed vein” method.

Correlation between nasal nitric oxide and its metabolites, RANTES, IL-5 in allergic rhinitis

There have been two measurement methods for nasal nitric oxide (nNO): direct measurement of nNO and indirect measurement of NO metabolites or the NO synthase enzyme. The aim of this study is to investigate the difference in nNO between allergic rhinitis (AR) patients and the correlation of the direct measurement of nNO and indirect measurement of nNO metabolites, RANTES, and IL-5. Fifteen patients with AR, 15 patients with septal deviation as a control group were enrolled. We measured the nNO level using a chemiluminescence analyzer and the amount of NO metabolites, RANTES, and IL-5 in nasal lavage fluid using the ELISA method. Nasal NO levels were significantly higher in AR than the control (195.7 ± 39.6 vs 159.4 ± 25.8 ppb, P = 0.027). NO metabolites, IL-5, and RANTES levels were higher in AR, but there was no statistically significant difference. There was no significant correlation between nNO and nNO metabolites, RANTES, IL-5, and clinical parameters except for the olfactory test score in AR. There was a negative correlation between nNO and the olfactory test score in AR ( r = −0.590, P = 0.034). Nasal NO concentration increased in AR. However, nNO metabolites and IL-5, RANTES in nasal secretion did not show any correlation with nNO. Direct measurement of nNO could be a potentially useful biomarker of AR compared to indirect measurement of NO metabolites, cytokines, and chemokines in nasal secretion.

INTENSITY OF NITRIC OXIDE SYNTHESIS IN THE BLOOD OF RATS UNDER THE INFLUENCE OF SODIUM FLUORIDE

The influence of fluoride ion as a chemical agent affects the metabolism, the change of which is manifested in functional and structural changes. The final stable metabolites of NO include nitrite and nitrate anions (NO2, NO3), the concentration of which serves as an indirect method for estimating the intensity of NO synthesis. The concentration of NO is a major factor in its numerical biological effects (regulatory, protective). At low NO concentrations, direct effects aimed at maintaining homeostasis, such as the vascular, respiratory, and nervous systems, predominate; at high concentrations of NO, indirect effects prevail, due primarily to the formation of peroxynitrite. It is known that when the rate of free radical reactions in the body increases, NO can react with a superoxide anion radical to form peroxynitrite, a highly reactive compound with destructive properties against proteins and lipids. Oral administration of FN to rats in doses of 1/10 and 1/100 DL50 leads to an increase in the content of nitrite and nitrate anions in the blood plasma during the first 30 days, which indirectly indicates excess production of nitric oxide, which in the initial stages of intoxication may play a compensatory role, but subsequently cause pathological reactions associated with the activation of oxidative stress. The decrease in nitrite and nitrate anions at the end of long-term action of FN indirectly indicates a decrease in nitric oxide generation, which may be associated, in particular, with an increase in peroxynitrite concentration due to the use of nitric oxide in reaction with superoxide anion radical and antioxidant deficiency.

The Effect of Eight Weeks of Water Resistance Training with Dark Chocolate Consumption on Plasma Levels of Endothelin-1, Nitric Oxide and Quality of Life in Elderly Women

Background: Vascular endothelial cells play an important role in regulating vascular activity by producing vascular active substances such as endothelin-1 and nitric oxide. The aim of this study was to investigate the effect of eight weeks of water resistance training with dark chocolate consumption on plasma levels of endothelin-1, nitric oxide and quality of life in elderly women. Materials and Methods: In this semi-experimental study, 37 elderly women (mean ± standard deviation; age, 65.6 ± 3.1 years; weight 75.71 ± 7.7 kg) were purposefully divided into four complementary groups. Supplementation and exercise, exercise and control were included. The training protocol was performed for eight weeks of water resistance training. Supplementation of 30 grams of 83% dark chocolate daily was used for 8 weeks. Quality of life index was measured by SF-36 evaluation and plasma endolin-1 levels by ELISA and serum nitrite levels as the main metabolite of NO. One-way analysis of variance and Bonferroni’s post hoc test were used for statistical analysis. Results: The results showed that the mean quality of life index in the water resistance training group was significantly higher than the control group in elderly women (p = 0.036). Also, the mean NO levels in the combined group were significantly higher than the control group (p = 0.001). But the mean levels of endothelin-1 in the combined group were significantly lower than the control group (p = 0.012). Conclusion: Based on the present results, it can be concluded that resistance training in water along with consumption of dark chocolate may reduce endothelin-1 levels and increase NO levels to improve endothelial function and increase quality of life in elderly women.

Beet on Alps: Time-course changes of plasma nitrate and nitrite concentrations during acclimatization to high-altitude

Nitric oxide seems to be involved in the altitude acclimatization process due to its ability to regulate pulmonary, cardiovascular and muscular responses to hypoxia. In this study, we investigated the plasma nitrate (NO3−) and nitrite (NO2−) response to hypobaric hypoxia in two groups of lowlanders exposed at different altitudes.For seven days, fourteen subjects were evaluated at Casati Hut (3269 m a.s.l. M.CEVEDALE) and eleven individuals were studied at Capanna Regina Margherita (4554 m a.s.l. M.ROSA). Before expeditions and at different time points during high-altitude sojourn, plasma NO3− and NO2− concentrations were measured by chemiluminescence. Resting peripheral arterial oxygen saturation (SpO2), heart rate (HR) and mean arterial blood pressure (MAP) were monitored during the experimental period. Possible confounding factors such as dietary NO3− intake, physical activity and altitude changes were controlled.Sea level plasma NO3− and NO2− concentrations significantly increased at altitude in both M.CEVEDALE group (+26.2 μM, p ≤ 0.0001, 95% CI [+17.6, +34.8] and +559.2 nM, p ≤ 0.0001, [+332.8, +785.6]) and M.ROSA group (+18.7 μM, p ≤ 0.0001, [+10.8, +26.5] and +463.7 nM, p ≤ 0.0001, [+314.3, +613.0]). Average peak value in NO metabolites concentration occurred earlier in M.CEVEDALE group vs M.ROSA group (NO3−, day 3 vs day 5, p = 0.007; NO2−, day 3 vs day 5, p = 0.019). In both groups, resting SpO2, HR and MAP values changed according to altitude levels.This study shows that exposure to hypobaric hypoxia affects nitric oxide metabolites, resulting in a significant increase in plasma NO3− and NO2− concentrations from sea level values. Interestingly, the higher the altitude reached, the longer the time taken to reach a peak in plasma concentrations of nitric oxide metabolites.

Activation of AT2 receptors prevents diabetic complications in female db/db mice by NO-mediated mechanisms.

The AT2 receptor plays a role in metabolism by opposing the actions triggered by the AT1 receptors. Activation of AT2 receptors has been shown to enhance insulin sensitivity in both normal and insulin resistance animal models. In this study, we investigated the mechanism by which AT2 receptors activation improves metabolism in diabetic mice. Female diabetic (db/db) and non-diabetic (db/+) mice were treated for 1 month with the selective AT2 agonist, compound 21 (C21, 0.3 mg·kg-1 ·day-1 , s.c.). To evaluate whether the effects of C21 depend on NO production, a subgroup of mice was treated with C21 plus a sub-pressor dose of the NOS inhibitor l-NAME (0.1 mg·ml-1 , drinking water). C21-treated db/db mice displayed improved glucose and pyruvate tolerance compared with saline-treated db/db mice. Also, C21-treated db/db mice showed reduced liver weight and decreased hepatic lipid accumulation compared with saline-treated db/db mice. Insulin signalling analysis showed increased phosphorylation of the insulin receptor, Akt and FOXO1 in the livers of C21-treated db/db mice compared with saline-treated counterparts. These findings were associated with increased adiponectin levels in plasma and adipose tissue and reduced adipocyte size in inguinal fat. The beneficial effects of AT2 receptors activation were associated with increased eNOS phosphorylation and higher levels of NO metabolites and were abolished by l-NAME. Chronic C21 infusion exerts beneficial metabolic effects in female diabetic db/db mice, alleviating type 2 diabetes complications, through a mechanism that involves NO production.

Evidence for placental-derived iron-nitrosyls in the circulation of the fetal lamb and against a role for nitrite in mediating the cardiovascular transition at birth.

Circulating metabolites of nitric oxide, such as nitrite, iron nitrosyls (FeNO), and nitrosothiols, have vasodilatory bioactivity. In both human and sheep neonates, plasma concentrations of these NO metabolite (NOx) concentrations fall >50% within minutes after birth, raising the possibility that circulating NOx plays a role in maintaining low fetal vascular resistance and in the cardiovascular transition at birth. To test whether the fall in plasma NOx concentrations at birth is due to either ligation of the umbilical cord or oxygenation of the fetus to newborn levels, plasma NOx concentrations were measured during stepwise delivery of near-term fetal lambs. When fetal lambs were intubated and mechanically ventilated with 100% O2 to oxygenate the arterial blood while still in utero with the umbilical circulation still intact, there was no change in plasma NOx levels. In contrast, when the umbilical cord was ligated while fetal lambs were mechanically ventilated with O2 levels that maintained fetal arterial blood gases, plasma NOx levels decreased by nearly 50%. Characterization of the individual NOx species in plasma revealed that the overall fall in NOx at birth was attributable mainly to FeNO compounds. Finally, when the typical fall in NOx after birth was prevented by intravenous nitrite infusion, birth-related changes in blood pressure, heart rate, and carotid flow changes were little affected, suggesting the cardiovascular transition at birth is not dependent on a fall in plasma NOx. In conclusion, this study shows FeNO is released from the placenta and that its decline accounts for most of the measured fall in plasma NOx at birth.

Hypoxic Exercise Training to Improve Exercise Capacity in Obese Individuals

Combining exercise training with hypoxic exposure has been recently proposed as a new therapeutic strategy to improve health status of obese individuals. Whether hypoxic exercise training (HET) provides greater benefits regarding body composition and cardiometabolic parameters than normoxic exercise training (NET) remains, however, unclear. We hypothesized that HET would induce greater improvement in exercise capacity and health status than NET in overweight and obese individuals. Twenty-three subjects were randomized into 8-wk HET (11 men and 1 woman; age, 52 ± 12 yr; body mass index, 31.2 ± 2.4 kg·m) or NET (eight men and three women; age, 56 ± 11 yr; body mass index, 31.8 ± 3.2 kg·m) programs (three sessions per week; constant-load cycling at 75% of maximal heart rate; target arterial oxygen saturation for HET 80%, FiO2 ~0.13, i.e., ~3700 m a.s.l.). Before and after the training programs, the following evaluations were performed: incremental maximal and submaximal cycling tests, measurements of pulse-wave velocity, endothelial function, fasting glucose, insulin and lipid profile, blood NO metabolites and oxidative stress, and determination of body composition by magnetic resonance imaging. Peak oxygen consumption and maximal power output increased significantly after HET only (peak oxygen consumption HET + 10% ± 11% vs NET + 1% ± 10% and maximal power output HET + 11% ± 7% vs NET + 3% ± 10%, P < 0.05). Submaximal exercise responses improved similarly after HET and NET. Except diastolic blood pressure which decreased significantly after both HET and NET, no change in vascular function, metabolic status and body composition was observed after training. Hypoxic exercise training only increased nitrite and reduced superoxide dismutase concentrations. Combining exercise training and hypoxic exposure may provide some additional benefits to standard NET for obese individual health status.