Search results for "nitric Oxide"
showing 10 items of 1075 documents
Nitric oxide and cortico-striato-pallidal motor circuitry: Quantitative EEG analysis of surface and depth recordings
2002
Rats treated with i.p. 7-NI showed a significant increase in cortical higher frequency EEG bands, associated with a corresponding and significant decrease in delta band activity. In the striatum, reduced levels of NO induced an increase in the low frequency band, and a decrease at higher frequencies. Pallidal depth recordings showed modifications to several frequency bands, similar to those found in the cortex. Although 7-NI was administered at increasing doses (from 40 to 70 mg kg–1), it was not possible to demonstrate a relationship between modified band activities and the dose of 7-NI. As suggested indirectly by the quantitative EEG data reported in this study, NO plays a fundamental rol…
Anti-inflammatory activity of flavonoids from Cayaponia tayuya roots.
2008
Taiuiá or tayuya (Cayaponia tayuya, Cucurbitaceae) is a climbing, lignified plant with a large swollen root that has traditionally been used as an anti-inflammatory and anti-rheumatic agent in the folk medicine of Brazil, Peru, and Colombia.We have assayed the pharmacological properties of a flavonoid fraction obtained from the butanol extract of Cayaponia tayuya roots using two models of topical mouse ear oedema, paying special attention to its influence on the induction on pro-inflammatory enzymes and peptidic mediators.The in vivo experiments involved both the acute oedema induced by a single application of TPA and the subchronic inflammation brought on by repeated applications of TPA. T…
Impairment of the modulatory role of nitric oxide on the endothelin-1-elicited contraction of cerebral arteries: a pathogenetic factor in cerebral va…
1997
OBJECTIVE: Nitric oxide (NO) and endothelin-1 (ET-1) are two endothelium-derived factors probably involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Our aim was twofold, i.e., to ascertain whether endothelial and nonendothelial NO modulates the contractile response of cerebral arteries to ET-1 and to analyze whether this relationship might be impaired after experimental SAH. METHODS: Rings of middle cerebral artery from goats in the control group and from goats with SAH were set up for isometric tension recordings. SAH was induced 3 days before the experiments by infusion of 10 ml of autologous arterial blood through a catheter previously inserted into t…
Fractional exhaled nitric oxide is associated with more severe asthma
2018
Fractional exhaled nitric oxide (FeNO) levels are used as a marker of airway inflammation. The aim of the present work was to evaluate a possible relationship between FeNO and parameters of asthma control and severity in different asthma phenotypes. FeNO was evaluated in 200 asthma patients (37% male, mean age ± SD 54±15 years, 19% controlled (GINA), 30% treated with oral corticosteroids (OCS), median FEV1 (interquartile range) 2,05 L (1,49-2,70), 74% pred. (56-90%)), together with other asthma characteristics (lung function, asthma control, allergies, serum IgE, serum ECP, and blood eosinophils). Patients with poorly controlled asthma had significantly higher FeNO values (ACQ-5≥1.5 vs. 70%…
Estradiol or genistein prevent Alzheimer's disease-associated inflammation correlating with an increase PPAR gamma expression in cultured astrocytes.
2009
Inflammation has been implicated in neurodegenerative disorders such as Alzheimer's disease (AD). The main inflammatory players in AD are the glial cells which initiate the inflammatory response. One of the earliest neuropathological changes in AD is the accumulation of astrocytes at sites of A beta deposition. It is desirable to find methods of tipping the balance towards anti-inflammatory state. Estrogenic compounds have shown anti-inflammatory and also antioxidant activity. Astrocytes were pretreated with 17-beta estradiol or with genistein, and 48 h later treated with 5 microM amyloid beta (A beta) for 24 h. We found that A beta induces inflammatory mediators, such as cyclooxygenase 2 (…
Oxidative stress and endothelial dysfunction: therapeutic implications.
2011
In a previous issue of Annals of Medicine, we presented evidence in support of the concept that an abnormally increased production of reactive oxygen species plays a central role in the genesis and progression of cardiovascular disease. While a number of preclinical lines of evidence support this concept, and despite the results of many studies suggesting a beneficial impact of antioxidant drugs on endothelial function, large clinical trials have failed to demonstrate a benefit of antioxidants on cardiovascular outcomes. Studies exploring the possibility that classical antioxidants such as vitamin C, vitamin E, selenium, or folic acid may improve the prognosis of patients with cardiac disea…
Janus-faced role of endothelial NO synthase in vascular disease: uncoupling of oxygen reduction from NO synthesis and its pharmacological reversal
2006
Endothelial NO synthase (eNOS) is the predominant enzyme responsible for vascular NO synthesis. A functional eNOS transfers electrons from NADPH to its heme center, where L-arginine is oxidized to L-citrulline and NO. Common conditions predisposing to atherosclerosis, such as hypertension, hypercholesterolemia, diabetes mellitus and smoking, are associated with enhanced production of reactive oxygen species (ROS) and reduced amounts of bioactive NO in the vessel wall. NADPH oxidases represent major sources of ROS in cardiovascular pathophysiology. NADPH oxidase-derived superoxide avidly interacts with eNOS-derived NO to form peroxynitrite (ONOO(-)), which oxidizes the essential NOS cofactor…
Pentaerithrityl tetranitrate improves angiotensin II induced vascular dysfunction via induction of heme oxygenase-1
2010
The organic nitrate pentaerythritol tetranitrate is devoid of nitrate tolerance, which has been attributed to the induction of the antioxidant enzyme heme oxygenase (HO)-1. With the present study, we tested whether chronic treatment with pentaerythritol tetranitrate can improve angiotensin II–induced vascular oxidative stress and dysfunction. In contrast to isosorbide-5 mononitrate (75 mg/kg per day for 7 days), treatment with pentaerythritol tetranitrate (15 mg/kg per day for 7 days) improved the impaired endothelial and smooth muscle function and normalized vascular and cardiac reactive oxygen species production (mitochondria, NADPH oxidase activity, and uncoupled endothelial NO synthase)…
LSC Abstract – Lung-derived prostacyclin (PGI) in endothelial dysfunction in db/db mice
2016
Aim: Increased risk of pulmonary hypertension and not clear response of pulmonary endothelium to diabetes were reasons to compare nitric oxide (NO) and PGI-dependent function in pulmonary and systemic circulation in diabetes type II. Methods: In fasted db mice (male, 20 weeks) we compared the function of pulmonary (isolated perfused lung-IPL) and aortic endothelium (wire myograph). It was supported by determination of nitrite(NO 2 - )/nitrate(NO 3 - ), PGI production, immunostaining (IMS) and western blot. Results: In diabetic IPL NO-dependent modulation of hypoxic pulmonary vasoconstriction was impaired but filtration coefficient increased; response to U46619 was enhanced; cumulative gener…
Effects of polymorphisms in endothelial nitric oxide synthase and folate metabolizing genes on the concentration of serum nitrate, folate, and plasma…
2015
Abstract Objectives A number of studies have explored the effects of dietary nitrate on human health. Nitrate in the blood can be recycled to nitric oxide, which is an essential mediator involved in many important biochemical mechanisms. Nitric oxide is also formed in the body from l -arginine by nitric oxide synthase. The aim of this study was to investigate whether genetic polymorphisms in endothelial nitric oxide synthase (eNOS) and genes involved in folate metabolism affect the concentration of serum nitrate, serum folate, and plasma total homocysteine in healthy individuals after folic acid supplementation. Methods In a randomized double-blind, crossover study, participants were given …