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Reports on gadolinium deposits in the body and brains of adults and children who underwent contrast-enhanced MRI examinations warrant development of new, metal free, contrast agents for MRI. Nitrate is an abundant ion in mammalian biochemistry and sodium nitrate can be safely injected intravenously. We show that hyperpolarized [N]nitrate can potentially be used as an MR tracer. The N site of hyperpolarized [N]nitrate showed a T of more than 100 s in aqueous solutions, which was prolonged to more than 170 s below 20 °C. Capitalizing on this effect for polarization storage we obtained a visibility window of 9 min in blood. Conversion to [N]nitrite, the bioactive reduced form of nitrate, was not observed in human blood and human saliva in this time frame. Thus, [N]nitrate may serve as a long-lived hyperpolarized tracer for MR. Due to its ionic nature, the immediate applications appear to be perfusion and tissue retention imaging.
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http://dx.doi.org/10.1016/j.jmr.2019.01.001 | DOI Listing |
Chemphyschem
September 2023
Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, 9112011, Israel.
Deuterated C sites in sugars (D-glucose and 2-deoxy-D-glucose) showed 6.3-to-17.5-fold higher solid-state dynamic nuclear polarization (DNP) levels than their respective protonated sites at 3.
View Article and Find Full Text PDFNutrients
June 2023
Instituto de Química, Programa de Pós-Graduação em Ciência de Alimentos e Programa de Pós-Graduação em Química, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 149, sala 545, Cidade Universitária, Rio de Janeiro 21941-909, RJ, Brazil.
Pathophysiological conditions such as endothelial dysfunction and arterial stiffness, characterized by low nitric oxide bioavailability, deficient endothelium-dependent vasodilation and heart effort, predispose individuals to atherosclerotic lesions and cardiac events. Nitrate (NO), L-arginine, L-citrulline and potassium (K) can mitigate arterial dysfunction and stiffness by intensifying NO bioavailability. Dietary compounds such as L-arginine, L-citrulline, NO and K exert vasoactive effects as demonstrated in clinical interventions by noninvasive flow-mediated vasodilation (FMD) and pulse-wave velocity (PWV) prognostic techniques.
View Article and Find Full Text PDFBiology (Basel)
May 2022
Department of Radiology, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
Nitrate, the inorganic anion NO, is found in many foods and is an endogenous mammalian metabolite, which is supplied mostly through the diet. Although much is known about the safety of sodium nitrate when given , methodological safety data on intravenous bolus injection of sodium nitrate to rodents are lacking. Recently, we have proposed a new use for nitrate, as a contrast agent for magnetic resonance imaging that will be metal free and leave no traces in the body and the environment further to the imaging examination.
View Article and Find Full Text PDFEur J Pharmacol
September 2020
Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, PR China. Electronic address:
Endothelial dysfunction is associated with a reduced bioavailability of nitric oxide (NO). In this study, the effects of 17β-estradiol supplement on endothelial function were examined in ovariectomized (OVX) rats following long-term inhibition of NO synthases with L-NAME. Female Sprague Dawley rats were ovariectomized at 12 weeks old.
View Article and Find Full Text PDFBiochem Pharmacol
August 2019
Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. Electronic address:
Sulodexide (SDX) is a highly purified glycosaminoglycan with antithrombotic and profibrinolytic properties and reported benefits in thrombotic and atherosclerotic vascular disorders. However, the effects of SDX on vascular function are unclear. We tested whether SDX affects vascular relaxation and examined the potential underlying mechanisms.
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