New Studies Show Spinach Nitrates Improves Endothelial Function, and more…
Scientific Updates Sponsored by Endothelix Inc. **************************************************** Food Nutr Res. 2016 Sep 9;60:32010. doi: 10.3402/fnr.v60.32010. eCollection 2016. Effects of spinach nitrate on insulin resistance, endothelial dysfunction markers and inflammation in mice with high-fat and high-fructose consumption. Li T1,2, Lu X1, Sun Y1, Yang X3. 1Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi’an, China. 2Centre for Cancer and Inflammation Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. 3Shaanxi Engineering Laboratory for Food Green Processing and Safety Control, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi’an, China; xbyang@snnu.edu.cn. Abstract BACKGROUND: Insulin resistance, which is associated with an increased risk of cardiovascular morbidity and mortality, has become a leading nutrition problem. Inorganic nitrate enriched in spinach has been demonstrated to reverse the pathological features of insulin resistance and endothelial dysfunction. However, the effects of a direct intake of nitrate-enriched spinach on insulin resistance and endothelial dysfunction have not been studied. OBJECTIVE: To investigate the effects of spinach nitrate on insulin resistance, lipid metabolism, endothelial function, and inflammation in mice fed with a high-fat and high-fructose diet. DESIGN: A diet intervention of spinach with or without nitrate was performed in mice. A high-fat and high-fructose diet was used to cause insulin resistance, endothelial dysfunction, and inflammation in mice. The impacts of spinach nitrate on lipid profile, insulin resistance, markers of endothelial function, and inflammation were determined in mice. RESULTS: Spinach nitrate improved the vascular endothelial function of the mice with high-fat and high-fructose consumption, as evidenced by the elevated plasma nitrite level, increased serum nitric oxide (NO) level and decreased serum ET-1 level after spinach nitrate intervention. Spinach nitrate also reduced serum triglycerides, total cholesterol, and low-density lipoprotein-cholesterol levels and elevated serum high-density lipoprotein-cholesterol levels in the mice fed with a high-fat and high-fructose diet. Mice receiving spinach with 60 mg/kg of nitrate (1.02±0.34) showed a significantly low homeostasis model assessment-insulin resistance index as compared with the model mice (2.05±0.58), which is indicating that spinach nitrate could effectively improve the insulin resistance. In addition, spinach nitrate remarkably decreased the elevated serum C-reactive protein, tumor necrosis factor α, and interleukin-6 levels induced by a high-fat and high-fructose diet. CONCLUSIONS: The intake of spinach nitrate can augment NO status, improve lipid homeostasis, relieve inflammation, and enhance endothelial function, suggesting that spinach is promising dietary supplements for insulin resistance prevention. J Am Heart Assoc. 2016 Sep 9;5(9). pii: e003183. doi: 10.1161/JAHA.115.003183. Age-Dependent Predictive Value of Endothelial Dysfunction for Arrhythmia Recurrence Following Pulmonary Vein Isolation. Matsuzawa Y1, Suleiman M2, Guddeti RR1, Kwon TG1, Monahan KH1, Lerman LO3, Friedman PA1, Lerman A4. Abstract BACKGROUND: The mechanisms of atrial fibrillation (AF) are highly divergent. The prevalence of AF increases significantly with age, and underling mechanisms might vary with age. Endothelial dysfunction may be associated with AF and atrial arrhythmia recurrence after catheter ablation. We tested the hypothesis that the impact of endothelial dysfunction on arrhythmia recurrence following catheter ablation is age dependent. METHODS AND RESULTS: This study enrolled 92 participants with AF undergoing catheter ablation. Endothelial function was assessed by peripheral arterial tonometry before ablation, and the natural logarithmic transformation of reactive hyperemia index was calculated. Endothelial dysfunction was defined as a natural logarithmic transformation of reactive hyperemia index 0.618 (median). Participants were followed for atrial tachycardia, flutter, and fibrillation recurrence for a median of 14 months. The mean age was 57±10 years. There was significant interaction between age and endothelial dysfunction in association with recurrence of AF (P=0.029) and any atrial arrhythmia (P=0.015), and the risk associated with endothelial dysfunction for arrhythmia recurrence was higher in younger versus older participants. Participants were divided into 2 age groups at a threshold of 60 years. Among participants aged equal or less than 60 years, multivariate Cox proportional hazards analysis revealed the independent association between endothelial dysfunction and increased risk of arrhythmia recurrence (hazard ratio for AF 4.18 [95% CI 1.33-15.82], P=0.014, and for any atrial arrhythmia 3.62 [95% CI 1.29-11.81], P=0.014). Kaplan-Meier analysis showed that participants with endothelial dysfunction had significantly higher rates of recurrence of AF (P=0.01) and any atrial arrhythmia (P=0.002). CONCLUSIONS: The risk associated with endothelial dysfunction for arrhythmia recurrence following catheter ablation was age dependent and was higher in younger participants. © 2016 The Authors and Mayo Foundation for Medical Education and Research. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell. NMR Biomed. 2016 Sep 7. doi: 10.1002/nbm.3599. [Epub ahead of print] Noninvasive mapping of endothelial dysfunction in myocardial ischemia by magnetic resonance imaging using an albumin-based contrast agent. Vandoorne K1, Vandsburger MH2, Jacobs I3, Han Y3, Dafni H4, Nicolay K3, Strijkers GJ3,5. 1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands. k.vandoorne@tue.nl. 2Department of Physiology, University of Kentucky, Lexington, KY, USA. 3Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands. 4Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel. 5Biomedical Engineering and Physics, Academic Medical Center (AMC), Amsterdam, the Netherlands. Abstract Noninvasive preclinical methods for the characterization of myocardial vascular function are crucial to an understanding of the dynamics of ischemic cardiac disease. Ischemic heart disease is associated with myocardial endothelial dysfunction, resulting in leakage of plasma albumin into the extravascular space. These features can be harnessed in a novel noninvasive three-dimensional magnetic resonance imaging method to measure fractional blood volume (fBV) and vascular permeability (permeability-surface area product, PS) using labeled albumin as a blood pool contrast agent. C57BL/6 mice were imaged before and 3 days after myocardial infarction (MI). Following the quantification of endogenous myocardial R1 , the dynamics of intravenously injected albumin-based contrast agent, extravasating from permeable myocardial blood vessels, were tracked on short-axis magnetic resonance images of the entire heart. This study successfully discriminated between infarcted and remote regions at 3 days post-infarct, based on a reduced fBV and increased PS in the infarcted region. These findings were confirmed using ex vivo fluorescence imaging and histology. We have demonstrated a novel method to quantify blood volume and permeability in the infarcted myocardium, providing an imaging biomarker for the assessment of endothelial dysfunction. Conclusion: This method has the potential to three-dimensionally visualize subtle changes in myocardial permeability and to track endothelial function for longitudinal cardiac studies determining pathophysiological processes during infarct healing. Click Here to View Previous Scientific Updates Sponsored by Endothelix Inc. ************************************************************************************
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