Search results for " nitrite"

Influence of plant traits, soil microbial properties, and abiotic parameters on nitrogen turnover of grassland ecosystems

2016

International audience; Although it is known that multiple interactions among plant functional traits, microbial properties , and abiotic soil parameters influence the nutrient turnover, the relative contribution of each of these groups of variables is poorly understood. We manipulated grassland plant functional composition and soil nitrogen (N) availability in a multisite mesocosm experiment to quantify their relative effects on soil N turnover. Overall, root traits, arbuscular mycorrhizal colonization, denitrification potential, as well as N availability and water availability, best explained the variation in measured ecosystem properties, especially the trade-off between nutrient sequest…

Inorganic nitrite and nitrate in cardiovascular therapy: A better alternative to organic nitrates as nitric oxide donors?

2017

In 1867 the organic nitrite, amyl nitrite, was introduced as a therapeutic agent in the treatment of angina pectoris and was later substituted by the organic nitrate nitroglycerin (NTG). Despite having a highly potent vasodilator capacity in veins>coronary arteries>arterioles, the vasodilator effects NTG are rapidly attenuated by the development of nitrate tolerance. We and others established that NTG treatment stimulates the production of reactive oxygen species such as superoxide and peroxynitrite with subsequent marked attenuation of the NTG vasodilator potency. The nitrite anion (NO2-) has more recently been characterized to possess novel pharmacotherapeutic actions such as modulation o…

Phosphodiesterase-5 Inhibition Alleviates Pulmonary Hypertension and Basal Lamina Thickening in Rats Challenged by Chronic Hypoxia

2018

javax.xml.bind.JAXBElement@6f8948ff Hypoxia represents both an outcome of cardiopulmonary diseases and a trigger for severe pulmonary complications as pulmonary hypertension. Because nitric oxide (NO) is a critical mediator in the development of pulmonary hypertension, the modulators of its downstream function may become target of pharmacological interventions aimed at alleviating the impact of this condition. Here, we investigate the effects of an early administration of phosphodiesterase-5 inhibitor in rats where pulmonary artery hypertension was induced by chronic exposure to hypoxia. javax.xml.bind.JAXBElement@162dc677 Rats were divided into three groups: normoxic control, hypoxic with …

Influence of risk factors on nitric oxide metabolites at the initial stage of juvenile acute myocardial infarction.

2009

Few data are accessible about the nitric oxide (NO) stable end-products (nitrite/NO2 − and nitrate/NO3 − :N O x) in acute coronary syndromes. An increase in inducible NO synthase (iNOS) was found during experimental myocardial infarction [13] and this increase persisted for 2 weeks. In experimental models of acute myocardial infarction (AMI) other authors [2] observed a NOx increase, a correlation between NOx level and iNOS activity and an inhibitory action carried out by S-methylisothiourea, that is an iNOS inhibitor [5]. The NOx level was also measured in a small group of patients with myocardial infarction in whom the peak of NOx elevation occurred 2 and 3 days after the onset of symptom…

Mechanism of interaction of betanin and indicaxanthin with human myeloperoxidase and hypochlorous acid.

2005

Hypochlorous acid (HOCl) is the most powerful oxidant produced by human neutrophils and contributes to the damage caused by these inflammatory cells. It is produced from H2O2 and chloride by the heme enzyme myeloperoxidase (MPO). Based on findings that betalains provide antioxidant and anti-inflammatory effects, we performed the present kinetic study on the interaction between the betalains, betanin and indicaxanthin, with the redox intermediates, compound I and compound II of MPO, and its major cytotoxic product HOCl. It is shown that both betalains are good peroxidase substrates for MPO and function as one-electron reductants of its redox intermediates, compound I and compound II. Compoun…

Betanin inhibits the myeloperoxidase/nitrite-induced oxidation of human low-density lipoproteins

2007

Production of nitrogen dioxide by the activity of myeloperoxidase (MPO) in the presence of nitrite is now considered a key step in the pathophysiology of low-density lipoprotein (LDL) oxidation. This study shows that betanin, a phytochemical of the betalain class, inhibits the production of lipid hydroperoxides in human LDL submitted to a MPO/nitrite-induced oxidation. Kinetic measurements including time-course of particle oxidation and betanin consumption, either in the presence or in the absence of nitrite, suggest that the antioxidant effect is possibly the result of various actions. Betanin scavenges the initiator radical nitrogen dioxide and can also act as a lipoperoxyl radical-scaven…

ANALYSIS OF THE DOSE-RESPONSE CURVE TO SODIUM NITRITE IN ISOLATED RAT AORTA

1978

Industrial and culinary practice effects on biologically active polyamines level in turkey meat

2021

Polyamines, including putrescine, spermidine, and spermine, are biological compounds present in nearly all food items. Their desirable physiological effects include cell division and growth. Hence, are undesirable in the diet of patients with tumor. This study aimed to assess the impact of curing agents (sodium chloride (0–2 g), sodium nitrite (0–200 ppm), sodium polyphosphate (0–0.5 g), and ascorbic acid (0–500 ppm)), cooking (frying (180°C), and boiling (100°C)) on polyamine contents in turkey breast meat using response surface methodology based on central composite design and dispersive liquid-liquid microextraction. Postprocessing changes were investigated using a high-performance liqui…

Electrochemical exfoliation-streamline method for synthesis of nitrogen doped graphene

2021

The authors gratefully acknowledge financial support from the Latvian Council of Science, Project LZP FLPP No. LZP-2018/1 0194, and the Institute of Solid State Physics, University of Latvia that as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2026-2017-TeamingPhase2 under Grant Agreement No. 739508, Project CAMART2.

Synthesis and structure verification of two previously uncharacterized pentachlorobiphenyls: PCB 108 and PCB 127

1992

Abstract The synthesis and structure verification of two previously uncharacterized polychlorinated biphenyl (PCB) congeners mono- ortho -substituted 2,3,3′,4,5′-pentachlorobiphenyl (PCB 108) and non- ortho -substituted 3,3′,4,5,5′-pentachlorobiphenyl (PCB 127) is described. The synthesis was done by the method of aromatic arylation in the presence of isopentyl nitrite. The purification and separation of the compounds was done by flash-chromatography on Al2O3- and charcoal columns. The structures were verified by 1H NMR, 13C NMR, IR and mass spectroscopy.