Plasma Nitric Oxide Levels Research Articles

Synchronized research on endothelial dysfunction and microcirculation structure in dorsal skin of rats with type 2 diabetes mellitus.

The aim of this study was to explore changes in the microvascular tone as measured by laser Doppler flowmetry (LDF) and the microcirculation structure of the dorsal skin of rats with type 2 diabetes mellitus. The diabetic rat model was induced by a diet of high-sugar and high-lipid fodder combined with the injection of streptozotocin into the abdominal cavity. Depending on the interval between the development of diabetes and the experiments, the diabetic rats were subdivided into three groups. The evaluation of microvascular tone was based on the amplitude responses of the LDF signal fluctuations in the appropriate frequency range in the dorsal skin of the rats during a thermal test (at 42°C). The nitric oxide (NO) level in plasma was also used as a marker of endothelial dysfunction. Changes in the microcirculation structure in the diabetic rats were estimated by measuring the microvascular density in the choke vessels of the dorsal skin of the rats. The experimental results with respect to red blood cell (RBC)-related parameters showed decreased hematocrit and hemoglobin levels and increased standard deviation of the width of the RBC distribution in three diabetic rats. The increasing fluctuation amplitudes diminished in the endothelial frequency range in response to the thermal test and this was accompanied by abnormal NO levels in plasma of the diabetic groups as compared with healthy rats. A significant reduction in the microvascular density of the choke vessels of the dorsal skin was found only in the diabetic group at the most advanced stage of diabetes in this experiment. Thus, we suggest that endothelial dysfunction occurs in diabetic rats and changes in the microcirculation structure of the dorsal skin occur in a later stage of diabetes development. A. Photograph of measurement method by using a LDF probe and heating device in the dorsal skin of the rat. B. Dorsal skin LDF signals of a healthy rat during the thermal stimuli test. (a) Blood flow signal record for the test. Wavelet filtration of blood flow signal in (b) myogenic range, (c) neurogenic range, and (d) endothelial range.

Origanum vulgare L. leaf extract alleviates finasteride-induced oxidative stress in mouse liver and kidney

Objective: To investigate the hepatorenoprotective effects of Origanum vulgare L. against finasteride-induced oxidative injury in the liver and kidney of mice. Methods: Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI/MS) analysis was utilized to yield a fingerprint of Origanum vulgare polyphenolic constituents. Thirty BALB/c mice received 0.5 mL/day distilled water, finasteride (25 mg/kg/day for 10 d), and 100, 200, or 400 mg/kg/day finasteride + Origanum vulgare extract with 6 mice per group for five weeks. On day 36, liver and kidney function as well as pro- and antiinflammatory (IFN-γ, IL-12, IL-6, TNF-α, IL-1β, and IL-10) cytokines were measured. The total antioxidant status, nitric oxide (NO), and malondialdehyde levels as well as the activities of NO synthase and catalase were also evaluated. Histopathological study was conducted to assess the effect of Origanum vulgare extract on finasteride-induced renal and hepatic toxicities. Results: Twenty-five major polyphenolic compounds were identified in the Origanum vulgare extract by LC-ESI/MS. Origanum vulgare extract, especially at 200 and 400 mg/kg/day doses, significantly improved liver and kidney biochemical indices, decreased inflammatory cytokines, increased total antioxidant status and NO synthase and catalase activities, as well as decreased plasma NO and malondialdehyde levels in a dose-dependent manner as compared to the finasteride group. Histopathological results further confirmed the protective effect of Origanum vulgare extract. Conclusions: Origanum vulgare extract ameliorates finasteride-induced hepatic and renal biochemical and histopathological alterations, and restores antioxidant/oxidant balance.

N-METHYL-D-ASPARTATE RECEPTOR INHIBITION PREVENTS GLUCOMETABOLIC DYSREGULATION AND CARDIAC INJURY IN NICOTINE-EXPOSED MALE RATS

Objective: Since non-smoking nicotine exposure has been associated with cardiometabolic disorders and smoking cessation therapies are of great global and medical significance. N-methyl-D-aspartate receptor (NMDAR) activity has been implicated in diabetes. Although NMDAR is also expressed in cardiomyocytes, there is dearth of information on its activity on cardiometabolic dysfunctions and its associated mechanism yet to be fully elucidated. It is therefore hypothesized that NMDAR inhibition by low-dose ketamine would improve nicotine-induced glucometabolic deregulation and cardiac injury. Design and method: Male Wistar rats (n = 6/group) aged 10 weeks were given (p.o.) vehicle, nicotine (1.0 mg/kg) with or without ketamine (0.2 mg/kg) daily for 28 days. Oral glucose tolerance test was performed 24-hours to the end of the experiment. The insulin resistance was estimated using the homeostasis model assessment for insulin resistance (HOMA-IR). Results: Data showed that nicotine exposure led to insulin resistance, hyperinsulinemia, elevated 1-hour postload glucose, glucose intolerance, triglyceride-glucose index. Likewise, plasma and cardiac uric acid, malondialdehyde, lactate, triglyceride (TG), TG/HDL-C, oxidized glutathione (GSSG) levels, creatinine kinase (CK), lactate dehydrogenase (LDH), adenosine deaminase (ADA), xanthine oxidase (XO) activities were increased in nicotine-exposed rats. On the other hand, plasma and cardiac nitric oxide level was reduced by nicotine exposure. However, ketamine treatment also led to elevated TG, LDH, lactate, CK activity, nitric oxide, and reduced TG/HDL-C, uric acid, MDA, GSSG levels, XO and ADA activities when compared to control. However, these nicotine-induced cardiometabolic disorders were ameliorated in ketamine-treated rats. Conclusions: The results demonstrated that low-dose ketamine prevents glucose dysregulation, plasma and cardiac TG, uric acid, lactate accumulation and suppressed ADA, XO and CK activities. Therefore, these findings imply that inhibition of NMDAR by low dose-ketamine improves glucometabolic regulation and ameliorates cardiac injury through ADA/XO/CK-dependent mechanisms.

Relationship between plasma asymmetric dimethylarginine and nitric oxide levels affects aerobic exercise training-induced reduction of arterial stiffness in middle-aged and older adults.

[Purpose]Aerobic exercise training (AT) reverses aging-induced deterioration of arterial stiffness via increased arterial nitric oxide (NO) production. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, was decreased by AT. However, whether AT-induced changes in ADMA levels are related to changes in nitrite/nitrate (NOx) levels remains unclear. Accordingly, we aimed to clarify whether the relationship between plasma ADMA and NOx levels affected the AT-induced reduction of arterial stiffness in middle-aged and older adults.[Methods]Thirty-one healthy middle-aged and older male and female subjects (66.4 ± 1.3 years) were randomly divided into two groups: exercise intervention and sedentary controls. Subjects in the training group completed an 8-week AT (60%–70% peak oxygen uptake [] for 45 min, 3 days/week).[Results]AT significantly increased (p < 0.05) and decreased carotid β-stiffness (p < 0.01). Moreover, plasma ADMA levels were significantly decreased while plasma NOx levels and NOx/ADMA ratio were significantly increased by AT (p < 0.01). Additionally, no sex differences in AT-induced changes of circulating ADMA and NOx levels, NOx/ADMA ratio, and carotid β-stiffness were observed. Furthermore, the AT-induced increase in circulating ADMA levels was negatively correlated with an increase in circulating NOx levels (r = -0.414, p < 0.05), and the AT-induced increase in NOx/ADMA ratio was negatively correlated with a decrease in carotid β-stiffness (r = -0.514, p < 0.01).[Conclusion]These results suggest that the increase in circulating NOx with reduction of ADMA elicited by AT is associated with a decrease in arterial stiffness regardless of sex in middle-aged and older adults.

Extract of varieties of guava (Psidium guajava L.) leaf modulate angiotensin-1-converting enzyme gene expression in cyclosporine-induced hypertensive rats

BackgroundHypertension has become a serious health problem with which people have to live day by day, it sometimes results in severe organ damage with a dead end. Management with Psidium guajava L. (guava) leaf extract through modulation of angiotensin-converting enzyme (ACE) mRNA expression would give succor to patients with hypertension. However, there are several reports on medicinal efficacy of guava leaf with dearth of information on its varieties. HypothesisElevation of the ACE mRNA level in the kidney plays a primary role in the acceleration of local angiotensin II formation and thus sustain hypertension. Studies have shown the significance of investigating the molecular mechanism of ACE activities in pathophysiological states, this work sought to investigate the modulatory effect of aqueous extract of leaf from different varieties of guava on ACE mRNA gene expression in cyclosporine-induced hypertensive rats. MethodsHypertension was induced via intraperitoneal (i.p) administration of cyclosporine (25mg/kg/day); an aqueous extract of leaves from white, red, and pink guava was prepared, 250 and 500mg/kg body weight of the extracts were administered to the rats by oral gavage for 7 days. The systolic (SBP) and diastolic (DBP) blood pressure was measured, ACE mRNA expression level was determined using RT-qPCR, with kidney function markers in plasma (creatinine, urea, and uric acid), plasma nitric oxide level, the kidney histopathology, as well as phenolic characterization of the guava leaves. ResultsThe results showed a significant (p<0.05) increase in SBP, DBP, plasma creatinine, urea, and uric acid concentration, as well as nitric oxide level with up-regulation of ACE gene expression in the rats' kidneys with severe glomerular damage, necrosis, and capillary collapse. However, a significant (p<0.05) down-regulation of ACE mRNA expression level, reduced serum creatinine, urea, and uric acid concentration with mild-moderate kidney damage was observed in the treated rats. The leaves extract characterization and quantification revealed chlorogenic acid, rutin, vanillic acid, and quercetin as the most abundant phenolic compounds in the leaves. ConclusionsThe oral administration of the aqueous extract of different varieties of guava leaf (rich in phenolics), reduced SBP, DBP, kidney function markers concentration in the plasma, with increased plasma nitric oxide level, ameliorate kidney damage, and down-regulate renal ACE gene expression with no significant (p>0.05) difference in activities of extracts from different varieties of guava leaves used for this study. This could be a useful therapeutic measure for the treatment/management of hypertension.

Impaired activity of circulating EPCs and endothelial function are associated with increased Syntax score in patients with coronary artery disease.

It has previously been shown that the number of endothelial progenitor cells (EPCs) is negatively correlated with Syntax score in patients with coronary artery disease (CAD). However, the association between alterations in EPC function and Syntax score is still unknown. The present study evaluated the association between the activity of EPCs as well as endothelial function and Syntax score in patients with CAD and investigated the underlying mechanisms. A total of 60 patients with CAD were enrolled in 3 groups according to Syntax score, and 20 healthy subjects were recruited as the control group. The number and migratory, proliferative and adhesive activities of circulating EPCs were studied. The endothelial function was measured by flow-mediated dilatation (FMD) and the levels of nitric oxide (NO) in plasma or secreted by EPCs were detected. The number and activity of circulating EPCs were lower in patients with a high Syntax score, which was similar to the alteration in FMD. The level of NO in plasma or secreted by EPCs also decreased as Syntax score increased. There was a negative association between FMD or circulating EPCs and Syntax score. A similar association was observed between the levels of NO in plasma or secreted by EPCs and Syntax score. Patients with CAD who had a higher Syntax score exhibited lower EPC numbers or activity and weaker endothelial function, which may be associated with attenuated NO production. These findings provide novel surrogate parameters for evaluation of the severity and complexity of CAD.

Hyperglycemia Potentiates Prothrombotic Effect of Aldosterone in a Rat Arterial Thrombosis Model

We investigated the role of aldosterone (ALDO) in the development of arterial thrombosis in streptozotocin-induced diabetic rats. To evaluate the effect of endogenous ALDO, the rats underwent adrenalectomy (ADX). ADX reduced the development of arterial thrombosis. A 1 h infusion of ALDO (30 μg/kg/h) enhanced thrombosis in adrenalectomized rats, while this effect was potentiated in diabetic rats. ALDO shortened bleeding time, increased plasma levels of tissue factor (TF) and plasminogen activator inhibitor, decreased plasma level of nitric oxide (NO) metabolites, and increased oxidative stress. Moreover, 2 h incubation of human umbilical vein endothelial cells (HUVECs) with ALDO (10−7 M) disrupted hemostatic balance in endothelial cells in normoglycemia (glucose 5.5 mM), and this effect was more pronounced in hyperglycemia (glucose 30 mM). We demonstrated that the acute ALDO infusion enhances arterial thrombosis in rats and hyperglycemia potentiates this prothrombotic effect. The mechanism of ALDO action was partially mediated by mineralocorticoid (MR) and glucocorticoid (GR) receptors and related to impact of the hormone on primary hemostasis, TF-dependent coagulation cascade, fibrinolysis, NO bioavailability, and oxidative stress balance. Our in vitro study confirmed that ALDO induces prothrombotic phenotype in the endothelium, particularly under hyperglycemic conditions.

БИОМАРКЕРЫ РАННЕЙ ДИАГНОСТИКИ НЕКРОТИЗИРУЮЩЕГО ЭНТЕРОКОЛИТА У ДОНОШЕННЫХ НОВОРОЖДЕННЫХ

Objective of the research: to assess the value of new biomarkers – erythropoietin (EPO), nitric oxide (NO), calcium ion for the early diagnosis of necrotizing enterocolitis (NEC) in full-term newborns. Materials and methods: 100 full-term infants with NEC and 30 generally healthy infants (control group) were examined. In newborns of both groups in the first 2 weeks of life, plasma NO levels were determined by the colorimetric method (Caymans Nitrate/Nitrite Colorimetric Assay Kit) using an ELISYS UNO HUMAN; EPO – by Human Enzyme Immunoassay ELISA Kit, calcium ions – by a photometric test with BioScreen MS2000. Results: an increase in EPO levels and a decrease in Ca+2 level were revealed in patients depending on the NEC stage. In patients with stage I NEC, EPO and NO values increased by 54% and 46%, respectively, and the Ca+2 values were decreased by 19% in comparison with indicators in children of the control group. In patients with stage II NEC, EPO values increased by 70%, NO – by 124%, and Ca+2 were decreased by 61% compared to the indicators of children in the control group. In patients with stage III NEC, EPO values increased by 100%, NO – by 222% compared with the indicators of children in the control group. Conclusion: EPO, NO, and Ca+2 are biomarkers of early diagnosis of NEC in term infants and detection of severe variants of the disease.

The Hepatoprotective mechanisms of 17β-estradiol after traumatic brain injury in male rats: Classical and non-classical estrogen receptors

Protective effects of estrogen (E2) on traumatic brain injury (TBI) have been determined. In this study, the hepatoprotective effects of E2 after TBI through its receptors and oxidative stress regulation have been evaluated. Diffuse TBI induced by the Marmarou method in male rats. G15, PHTPP, MPP, and ICI182–780 as selective antagonists of E2 were injected before TBI. The results indicated that TBI induces a significant increase in liver enzymes [Alkaline phosphatase (ALP), Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Glutamyl transferase (GGT)], and oxidants levels [Malondialdehyde (MDA), Nitric oxide (NO)] and decreases in antioxidant biomarkers [Glutathione peroxidase (GPx) and Superoxide dismutase (SOD)] in the brain and liver, and plasma. We also found that E2 significantly preserved levels of these biomarkers and enzymatic activity. All antagonists inhibited the effects of E2 on increasing SOD and GPx. Also, the effects of E2 on brain MDA levels were inhibited by all antagonists, but in the liver, only ICI + G15 + E2 + TBI group was affected. The impacts of E2 on brain and liver and plasma NO levels were inhibited by all antagonists. The current findings demonstrated that E2 probably improved liver injury after TBI by modulating oxidative stress. Also, both classic (ERβ, ERα) and non-classic [G protein-coupled estrogen receptor (GPER)] receptors are affected in the protective effects of E2.

Correlation between smokeless tobacco (Gutkha) and biomarkers of oxidative stress in plasma with cardiovascular effects

Tobacco products are widely consumed around the world in smoking and smokeless tobacco (SLT) forms. Analysis of smokeless tobacco consumption suggested that the effects of nicotine and tobacco-specific N-nitrosamines, the main ingredients of smokeless tobacco are attractive to study because its consumption often results in biochemical changes of plasma parameters and markers of oxidative stress development. Smokeless tobacco users generally consume the most commonly available SLT products like khaleja brand of gutkha and mahak chaini brand of khaini 3–5 times per day. We found a significant increase in plasma glucose levels, total cholesterol, triglycerides, and a significant decrease in high-density lipoprotein (HDL) cholesterol indicative of atherosclerosis risk. We also found that the plasma peroxynitrites (ONOO−), nitric oxide (NO), lipid peroxidation (LPO), and protein carbonyls (PCO) levels were significantly elevated. Plasma nicotine and cotinine levels were significantly elevated in study subjects, suggesting that nicotine could be responsible for the oxidative and nitrosative stress indirectly inducing cardiovascular risk. There was a strong correlation of nicotine with reactive oxygen species (ROS), reactive nitrogen species (RNS), cholesterol, and creatinine in exposed smokeless tobacco (gutkha) consumers. These data demonstrate SLT users are at high cardiovascular risk due to nicotine-induced free radicals and oxidative damage.

Evaluation of biomarkers of oxidative stress and female reproductive hormones in post menopausal women with breast cancer in Southern Nigeria.

Reproductive hormones and reactive oxygen species produced by either hormonal or aerobic metabolism have been implicated in carcinogenesis of the breast and disease progression. Perturbations in the homeostasis of female reproductive hormones and oxidative stress indices in breast cancer (BCa) could be used for monitoring disease prognosis. The aim of this study was to assess levels of some biomarkers of oxidative stress and female reproductive hormones in postmenopausal women with BCa at different stages. Reduced glutathione (GSH), total antioxidant capacity (TAC), total plasma peroxides (TPP), nitric oxide (NO), malondialdehyde (MDA), estradiol (E2), and prolactin (PRL) levels were determined in 50 post-menopausal women with BCa (stages II-IV) and 50 women without BCa (controls) by colorimetry and ELISA methods. Oxidative stress and body mass indices (OSI &BMI) and clinical history were obtained. Post-menopausal women with BCa had significantly higher BMI (26.60 ± 5.17 vs 22.73 ± 1.21 kg/m2, P=<0.001), TAC (5.59 ± 2.38 vs 4.43 ± 2.66 mmol/l, P = 0.023), TPP (4.92 ± 3.59 vs 2.98 ± 2.82 mmol/l, P = 0.003), NO (31.96 ± 10.73 vs 23.92 ± 6.37 μmol/l, P=<0.001) and E2 (78.89 ± 54.54 vs 11.08 ± 14.80 pg/ml, P = 0.003) levels and lower mean age at menarche (13.16 ± 0.87 vs 14.14 ± 1.60 years, P=<0.001) compared to controls. Controls had significantly lower E2 (P = 0.003), TPP (P = 0.005) and OSI (P = 0.043) compared to women with stage II BCa; lower E2 (P=<0.001), NO (P = 0.010), TAC (P = 0.010) and TPP (P=<0.001) compared to stage III BCa; and lower E2, (P=<0.001), NO (P = 0.044) and MDA (P = 0.020) compared to stage IV BCa respectively. Prolactin correlated positively with E2 (r = 0.296, P = 0.037), and TAC (r = 0.336, P = 0.011) in women with BCa. Postmenopausal women with BCa at different stages have increased estradiol, antioxidants, lipid peroxidation, and oxidative stress index suggesting that these indices may be useful for clinical assessment and monitoring progression of breast cancer.

Gynura procumbens ethanol extract improves vascular dysfunction by suppressing inflammation in postmenopausal rats fed a high-fat diet

Context Gynura procumbens (Lour.) Merr. (Asteraceae) has been reported to have various pharmacological activities including anti-inflammatory effects. Objective This study sought to determine whether Gynura procumbens (GP) could improve vascular reactivity by suppressing inflammation in postmenopausal rats fed with five-times heated palm oil (5HPO) diet. Materials and methods Forty-eight female Sprague-Dawley rats were randomly divided into sham [non-ovariectomized; grouped as control, GP extracts (250 and 500 mg/kg), atorvastatin (ATV, 10 mg/kg)] and postmenopausal (PM) groups [ovariectomized rats fed with 5HPO; grouped as PM, GP extracts (250 and 500 mg/kg) and ATV (10 mg/kg)]. Each group (n = 6) was either supplemented with GP extract or ATV orally once daily for 6 months. Results In comparison with the untreated PM group, 250 and 500 mg/kg GP supplementation to PM groups reduced the systolic blood pressure (103 ± 2.7, 86 ± 2.4 vs. 156 ± 7.83 mmHg, p < 0.05), intima-media thickness (101.28 ± 3.4, 93.91 ± 2.93 vs. 143.78 ± 3.31 µM), vasoconstriction percentage induced by phenylephrine (102.5%, 88.3%, vs. 51.8%), sICAM-1 (0.49, 0.26 vs. 0.56 pg/mL) and sVCAM-1 (0.39, 0.25 vs. 0.45 pg/mL). GP extract supplementation increased vasorelaxation percentage induced by acetylcholine (78.4% vs. 47.3%) and sodium nitroprusside (84.2% vs. 53.7%), increased changes in plasma nitric oxide level (1.25%, 1.31% vs. 1.9%), and suppressed the elevation of TNF-α (0.39 vs. 1.02 pg/mL), IL-6 (0.43 vs. 0.77 pg/mL) and CRP (0.29 vs. 0.69 ng/mL) in the PM groups. Conclusions GP extract might improve vascular dysfunction by suppressing the inflammatory response, consequently preventing blood pressure elevation.

Effect of ACE Plus Selenium on Total Antioxidant/Oxidant Capacity and Nitric Oxide Levels in Rabbits

Pills including vitamins and minerals have been used as part of sedentary lifestyle, malnutrition, aging, and of age-related ilnesses in developed countries. This study specefically focuses on the effect of ACE Plus Selenium given rabbits through intraperitoneal (i.p) injection on their total oxidant, antioxidant capacity (TOC, TAC), and nitric oxide (NO) levels.In this study, 0,5 ml/kg of normal saline was injected to rabbits in control group and 0,5 ml/kg of ACE Plus Selenium was conducted to the treatment group for twice (every other day) via i.p route. Following the injection, plasmas of blood samples obtained in the second and fourth days, were seperated, and stored at -20ºC till the analysis. Plasma TAC, TOC and NO levels were determined spectrophotometrically. The TOC, TAC and NO levels of the rabbits were compared to the control group statistically. While TOC levels were observed to decrease (p

L-Citrulline Supplementation Increases Plasma Nitric Oxide Levels and Reduces Arginase Activity in Patients With Type 2 Diabetes.

Type 2 diabetes mellitus (T2DM) is becoming a major contributor to cardiovascular disease. One of the early signs of T2DM associated cardiovascular events is the development of vascular dysfunction. This dysfunction has been implicated in increasing the morbidity and mortality of T2DM patients. One of the important characteristics of vascular dysfunction is the impaired ability of endothelial cells to produce nitric oxide (NO). Additionally, decreases in the availability of NO is also a major contributor of this pathology. NO is produced by the activity of endothelial NO synthase (eNOS) on its substrate, L-arginine. Reduced availability of L-arginine to eNOS has been implicated in vascular dysfunction in diabetes. Arginase, which metabolizes L-arginine to urea and ornithine, competes directly with NOS for L-arginine. Hence, increases in arginase activity can decrease arginine levels, reducing its availability to eNOS and decreasing NO production. Diabetes has been linked to elevated arginase and associated vascular endothelial dysfunction. We aimed to determine levels of plasma NO and arginase activity in (T2DM) patients and the effects of L-citrulline supplementation, a natural arginase inhibitor, on inhibiting arginase activity in these patients. Levels of arginase correlated with HbA1c levels in diabetic patients. Twenty-five patients received L-citrulline supplements (2000 mg/day) for 1 month. Arginase activity decreased by 21% in T2DM patients after taking L-citrulline supplements. Additionally, plasma NO levels increased by 38%. There was a modest improvement on H1Ac levels in these patients, though not statistically significant. The effect of L-citrulline on arginase activity was also studied in bovine aortic endothelial cells (BAECs) grown in high glucose (HG) conditions. HG (25 mM, 72 h) caused a 2-fold increase in arginase activity in BAECs and decreased NO production by 30%. L-citrulline (2.5 mM) completely prevented the increase in arginase activity and restored NO production levels. These data indicate that L-citrulline can have therapeutic benefits in diabetic patients through increasing NO levels and thus maintaining vascular function possibly through an arginase inhibition related pathway.

The role of endothelin-1 and nitric oxide affecting endothelial dysfunction in the etiopathogenesis of ischaemic heart disease

Introduction: Endothelial dysfunction is an imbalance in bioavailability of endothelium-derived relaxing (Nitric Oxide) and contracting factors (Endothelin). Studies have shown that NO has antiatherogenic property as it inhibits vascular smooth muscle contraction and proliferation, platelet aggregation and leukocyte adhesion. On the other hand, Endothelin-1 causes proliferation and vasoconstriction of myocytes resulting in elevated vascular tone thereby contributing to endothelial dysfunction. This dysfunction is a well-established response to cardiovascular risk factors and precedes the development of atherosclerosis. As a result, status of an endothelial dysfunction may reflect the propensity to develop atherosclerotic disease and may serve as a marker of an unfavourable cardiovascular prognosis. Materials and Methods: 50 cases of angiographically proven ischemic heart disease and 50 age and sex matched patients with no evidence of ischaemic heart disease on angiography were selected from G.B Pant Hospital, New Delhi, India. Serum levels of Endothelin were estimated by sandwich ELISA and nitric oxide levels by modified Griess reaction. Results: Serum levels of Endothelin were raised while nitric oxide levels were significantly reduced (p=0.049) in the cases as compared to controls. The mean plasma nitric oxide level in the study group (cases) was 23.51±13.48 µM and in the control group was 29.35±15.73 µM. The difference between the two was significant (p=0.049*). The mean plasma endothelin level in the study group was 3.04±1.37fmol/ml and in the control group was 2.95±1.70 fmol/ml. The difference between the two was not significant (p = 0.764). Conclusion: Higher Endothelin-1 and lower NO levels in cases suggest their role in causing endothelial dysfunction in ischemic heart disease patients. However, larger sample size is required to assess the role of Endothelin as a biomarker of endothelial dysfunction in patients of ischemic heart disease.

Ethanol extract of elecampane (Inula helenium L.) rhizome attenuates experimental cold-induced ascites (pulmonary hypertension syndrome) in broiler chickens

This study was designed to assess the preventive effect of an ethanol extract of elecampane (Inula helenium L.) rhizome (EEER) on ascites in broiler chickens. A total of 900 1-day-old male chicks (Ross 308) were assigned to five treatment groups, each of which had six pens of 30 chicks per pen. The control birds were housed in a thermoneutral chamber and fed a basal diet, while the other four groups were reared in a cold chamber to induce ascites and fed the basal diet supplemented with either 0, 500, 1000, or 2000 mg/kg of EEER. Associated with cold treatment, there were decreases in feed intake, body weight, and body weight gain and an increase in ascites mortality (P < 0.05), which coincided with increased hematological values (erythrocytes count, hemoglobin, and hematocrit) and induction of right ventricle hypertrophy at 24 and 42 days of age (P < 0.05). These adverse effects of the cold ambient condition could be linearly decreased by increasing the EEER content in the diet (P < 0.05), but they did not normalize to the control levels (P < 0.05). Also, at both 24 and 42 days of age, the cold-treated birds revealed an increase in malondialdehyde (MDA) contents in plasma and tissues (heart, liver, and lungs) that accompanied with a noticeable decline in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and an increase in plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities (P < 0.05). These changes paralleled a decrease in plasma nitric oxide (NO) levels (P < 0.05). Treatment with graded increments of EEER showed a linear decrease in MDA levels and linearly increased SOD and GPx activities (P < 0.05). However, it failed to restore the oxidative status of the heart and lungs towards close the control levels (P < 0.05), and this was also the case for ALT and AST activities and NO levels. In conclusion, EEER appears to be a useful dietary agent for attenuating the progression of cold-induced ascites in broiler chickens.

Rejuvenated Circulating Endothelial Progenitor Cells and Nitric Oxide in Premenopausal Women with Hyperhomocysteinemia

Hyperhomocysteinemia (HHcy) induced endothelial dysfunction is associated with disturbance in circulating endothelial progenitor cells (EPCs). Nevertheless, whether this unfavorable effect of HHcy on circulating EPCs also exists in premenopausal women is still unknown. Therefore, this leaves an area for the investigation of the difference on the number and activity of circulating EPCs in premenopausal women with hyperhomocysteinemia and its underlying mechanism. The number of circulating EPCs was measured by fluorescence-activated cell sorter analysis, as well as DiI-acLDL and lectin fluorescent staining. The migration and proliferation of circulating were evaluated by the Transwell chamber assay and MTT. Additionally, the endothelial function and levels of nitric oxide (NO), VEGF, and GM-CSF in plasma and culture medium were determined. The number or activity of circulating EPCs and flow-mediated dilatation (FMD) in premenopausal women with or without HHcy were higher than those in postmenopausal women. However, no significant effect of HHcy on the number or activity of circulating EPCs in premenopausal women was observed. A similar alteration in NO level between the four groups was observed. There was a correlation between FMD and the number or activity of EPCs, as well as NO level in plasma or secretion by EPCs. For the first time, our findings illuminated the quantitive or qualitative alterations of circulating EPCs and endothelial function in premenopausal patients with HHcy are preserved, which was associated with retained NO production. The recuperated endothelial repair capacity is possibly the potential mechanism interpreting cardiovascular protection in premenopausal women with HHcy.

Vitamin D (1,25-(OH)2D3) Improves Endothelial Progenitor Cells Function via Enhanced NO Secretion in Systemic Lupus Erythematosus.

It has been proven that vitamin D was decreased and function of circulating endothelial progenitor cells (EPCs) was injured in systemic lupus erythematosus (SLE) patients. However, the effect of vitamin D on the function of EPCs in vitro and its mechanism need further study. Therefore, we investigated whether vitamin D improved the function of EPCs in vitro. The peripheral blood mononuclear cells of the participants were isolated from SLE patients and control subjects and cultured to EPCs. After the EPCs were treated with vitamin D (1,25-(OH)2D3), we evaluated the number, migratory and proliferative activities, and nitric oxide (NO) production of EPCs in vitro and detected vascular endothelial function by flow-mediated dilatation (FMD). We found that vitamin D in a dose-dependent manner improved number and migratory and proliferative activities of EPCs from SLE patients. Additionally, vitamin D upregulated NO production from EPCs in vitro. A significant correlation between the FMD and plasma NO level was found. There was also a correlation between number, migration, and proliferation of EPCs and NO production. Thus, the present findings indicated that vitamin D improved the function of EPCs from SLE patients via NO secretion.

Effect of Diterpene Manool on the Arterial Blood Pressure and Vascular Reactivity in Normotensive and Hypertensive Rats.

ResumoFundamento:Diversos estudos têm mostrado que as classes de diterpenos exercem efeito significativo no sistema cardiovascular. Os diterpenos, em particular, estão entre os principais compostos associados às propriedades cardiovasculares, como a propriedade vasorrelaxante, inotrópica, diurética e a atividade hipotensora. Embora o mecanismo de vasorrelaxamento do manool seja visível, seu efeito sobre a pressão arterial (PA) ainda é desconhecido.Objetivo:Avaliar o efeito hipotensor in vivo do manool e verificar o efeito de vasorrelaxamento ex vivo em anéis aórticos de ratos.Métodos:Os animais foram divididos aleatoriamente em dois grupos: normotensos e hipertensos. O grupo normotenso foi submetido à cirurgia sham e adotou-se o modelo 2R1C para o grupo hipertenso. Realizou-se monitoramento invasivo da PA para testes com manool em diferentes doses (10, 20 e 40 mg/kg). Foram obtidas curvas de concentração-resposta para o manool nos anéis aórticos, com endotélio pré-contraído com fenilefrina (Phe) após incubação com Nω-nitro-L-arginina metil éster (L-NAME) ou oxadiazolo[4,3-a]quinoxalina-1-ona (ODQ). Os níveis plasmáticos de óxido nítrico (NOx) foram medidos por ensaio de quimioluminescência.Resultados:Após a administração de manool, a PA se reduziu nos grupos normotenso e hipertenso, e esse efeito foi inibido pelo L-NAME em animais hipertensos apenas na dose de 10 mg/kg. O manool ex vivo promoveu vasorrelaxamento, inibido pela incubação de L-NAME e ODQ ou remoção do endotélio. Os níveis plasmáticos de NOx aumentaram no grupo hipertenso após a administração de manool. O manool induz o relaxamento vascular dependente do endotélio na aorta de ratos, mediado pela via de sinalização NO/cGMP e redução da PA, e também pelo aumento plasmático de NOx. Esses efeitos combinados podem estar envolvidos na modulação da resistência periférica, contribuindo para o efeito anti-hipertensivo do diterpeno.Conclusão:Esses efeitos em conjunto podem estar envolvidos na modulação da resistência periférica, contribuindo para o efeito anti-hipertensivo do diterpeno.

Treatment of Obstructive Sleep Apnea-Hypopnea Syndrome With a Mandible Advanced Device Increases Nitric Oxide Release and Ameliorates Pulmonary Hypertension in Rabbits

To investigate the effects of mandible advanced device (MAD) therapy for obstructive sleep apnea-hypopnea syndrome (OSAHS) on nitric oxide (NO) release and changes in pulmonary artery pressure and structure. Thirty male New Zealand white rabbits were randomly divided into OSAHS, MAD, and control groups (n=10 per group). The soft palate of rabbits in the OSAHS and MAD groups was injected with hydrophilic polyacrylamide gel to induce OSAHS. The MAD group wore a MAD, and the control group was not treated. Cone-beam computed tomography scans and polysomnography recordings were performed to confirm successful model establishment. All rabbits slept in a supine position for 4 to 6hours daily and were observed for 8 consecutive weeks. The pulmonary artery pressure was measured by right heart catheterization. Pulmonary artery morphometry was analyzed by hematoxylin and eosin staining. NO levels in plasma and lung homogenate supernatants were detected by Griess reaction assay kits. The OSAHS group exhibited higher pulmonary artery pressure (57.74±1.79mm Hg) than the MAD (19.99±2.04mm Hg) and control (14.49±0.54mm Hg) groups. The media thickness percentage of the pulmonary artery was higher in the OSAHS group (46.89±2.72%) than the control group (15.87±1.18%) and was markedly reduced by MAD (21.64±1.45%). Blood oxygen saturation was positively correlated with the NO concentration in both the lung and plasma, and the NO concentration was negatively correlated with the media thickness percentage and media section percentage. OSAHS induced a decrease in NO and pulmonary hypertension, which was relieved by MAD therapy.