48 research outputs found

    New perspectives of nitric oxide donors in cardiac arrest and cardiopulmonary resuscitation treatment

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    Nitric oxide (NO) is often used to treat heart failure accompanied with pulmonary edema. According to present knowledge, however, NO donors are contraindicated when systolic blood pressure is less than 90 mmHg. Based on recent findings and our own clinical experience, we formulated a hypothesis about the new breakthrough complex lifesaving effects of NO donors in patients with cardiac arrest and cardiopulmonary resuscitation therapy. It includes a direct hemodynamic effect of NO donors mediated through vasodilation of coronary arteries in cooperation with improvement of cardiac function and cardiac output through reversible inhibition of mitochondrial complex I and mitochondrial NO synthase, followed by reduction in reactive oxygen species and correction of myocardial stunning. Simultaneously, an increase in vascular sensitivity to sympathetic stimulation could lead to an increase in diastolic blood pressure. Confirmation of this hypothesis in clinical practice would mean a milestone in the treatment for cardiac arrest and cardiopulmonary resuscitation

    Effect of Bioactive Compound of Aronia melanocarpa

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    Aronia melanocarpa has attracted scientific interest due to its dense contents of different polyphenols. We aimed to analyse effects of Aronia melanocarpa (AME) extract on blood pressure (BP), lipid peroxidation, cytokine level, total NOS activity in the left ventricle (LV), and aorta of L-NAME-induced hypertensive rats. 12-week-old male WKY rats were assigned to the control group and groups treated with AME extract (57.90 mg/kg/day), L-NAME (40 mg/kg/day), or combination of L-NAME (40 mg/kg/day) and AME (57.90 mg/kg/day) in tap water for 3 weeks. NOS activity, eNOS protein expression, and conjugated diene (CD) concentration were determined in the LV and aorta. After 3 weeks of L-NAME treatment, BP was increased by 28% and concomitant treatment with AME reduced it by 21%. NOS activity of the LV and aorta in the L-NAME group was decreased by about 40%, while AME increased it almost on the control level. AME-induced eNOS upregulation may contribute to increase NOS activity. Moreover, AME decreased CD concentration in the LV and aorta and TNF-α and IL-6 production in the plasma were increased by L-NAME treatment. In conclusion, our results showed that active substances of Aronia melanocarpa may have a positive effect on blood pressure, NOS activity, and proinflammatory processes in L-NAME-induced hypertension

    Paradoxical Effect of Nonalcoholic Red Wine Polyphenol Extract, Provinols™, in the Regulation of Cyclooxygenases in Vessels from Zucker Fatty Rats (fa/fa)

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    The aim of this work was to study the vascular effects of dietary supplementation of a nonalcoholic red wine polyphenol extract, Provinols, in Zucker fatty (ZF) obese rats. ZF or lean rats received diet supplemented or not with Provinols for 8 weeks. Vasoconstriction in response to phenylephrine (Phe) was then assessed in small mesenteric arteries (SMA) and the aorta with emphasis on the contribution of cyclooxygenases (COX). Although no difference in vasoconstriction was observed between ZF and lean rats both in SMA and the aorta, Provinols affected the contribution of COX-derived vasoconstrictor agents. The nonselective COX inhibitor, indomethacin, reduced vasoconstriction in vessels from both groups; however, lower efficacy was observed in Provinols-treated rats. This was associated with a reduction in thromboxane-A2 and 8-isoprostane release. The selective COX-2 inhibitor, NS398, reduced to the same extent vasoconstriction in aortas from ZF and Provinols-treated ZF rats. However, NS398 reduced response to Phe only in SMA from ZF rats. This was associated with a reduction in 8-isoprostane and prostaglandin-E release. Paradoxically, Provinols decreased COX-2 expression in the aorta, while it increased its expression in SMA. We provide here evidence of a subtle and paradoxical regulation of COX pathway by Provinols vessels from obese rats to maintain vascular tone within a physiological range

    Apoplast proteome reveals that extracellular matrix contributes to multistress response in poplar

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    <p>Abstract</p> <p>Background</p> <p>Riverine ecosystems, highly sensitive to climate change and human activities, are characterized by rapid environmental change to fluctuating water levels and siltation, causing stress on their biological components. We have little understanding of mechanisms by which riverine plant species have developed adaptive strategies to cope with stress in dynamic environments while maintaining growth and development.</p> <p>Results</p> <p>We report that poplar (<it>Populus </it>spp.) has evolved a systems level "stress proteome" in the leaf-stem-root apoplast continuum to counter biotic and abiotic factors. To obtain apoplast proteins from <it>P. deltoides</it>, we developed pressure-chamber and water-displacement methods for leaves and stems, respectively. Analyses of 303 proteins and corresponding transcripts coupled with controlled experiments and bioinformatics demonstrate that poplar depends on constitutive and inducible factors to deal with water, pathogen, and oxidative stress. However, each apoplast possessed a unique set of proteins, indicating that response to stress is partly compartmentalized. Apoplast proteins that are involved in glycolysis, fermentation, and catabolism of sucrose and starch appear to enable poplar to grow normally under water stress. Pathogenesis-related proteins mediating water and pathogen stress in apoplast were particularly abundant and effective in suppressing growth of the most prevalent poplar pathogen <it>Melampsora</it>. Unexpectedly, we found diverse peroxidases that appear to be involved in stress-induced cell wall modification in apoplast, particularly during the growing season. Poplar developed a robust antioxidative system to buffer oxidation in stem apoplast.</p> <p>Conclusion</p> <p>These findings suggest that multistress response in the apoplast constitutes an important adaptive trait for poplar to inhabit dynamic environments and is also a potential mechanism in other riverine plant species.</p

    Contribution of Central Nervous System to Hypertension: role of Angiotensin II and Nitric Oxide. Act Nerv Super Rediviva

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    Abstract The contribution of the central nervous system (CNS) to the development and maintenance of high blood pressure is well established. Increased activity of the sympathetic nervous system during hypertensive conditions has been demonstrated experimentally and clinically. Different types of dysregulation in CNS, as seen by alterations in neurotransmitter production and baroreceptor reflex function, have been detected in early stages of hypertension. It was demonstrated that centrally acting drugs such as a-methyldopa, clonidine or reserpine effectively lower blood pressure. Moreover, in animal experiments renal hypertension could be prevented by central chemical sympathectomy. And psychosocial stress-induced sustained hypertension is well-known present phenomenom. The biochemical mechanisms contributing to the blood pressure increase by means of CNS are however lesser-known. Since lowering of blood pressure by the inhibition of the renin-angiotensin-aldosterone system within peripheral but also central nervous system was documented by several studies, it seems that brain angiotensin II may play a key role in the contribution of CNS to hypertension. On the other hand, sufficient production of nitric oxide within the system may effectively prevent increase in blood pressure

    Therapeutic Potential of Polyphenols-Loaded Polymeric Nanoparticles in Cardiovascular System

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    Numerous studies document an increased production of reactive oxygen species (ROS) with a subsequent decrease in nitric oxide (NO) bioavailability in different cardiovascular diseases, including hypertension, atherosclerosis, and heart failure. Many natural polyphenols have been demonstrated to decrease ROS generation and/or to induce the endogenous antioxidant enzymatic defense system. Moreover, different polyphenolic compounds have the ability to increase the activity/expression of endothelial nitric oxide synthase (eNOS) with a subsequent enhancement of NO generation. However, as a result of low absorption and bioavailability of natural polyphenols, the beneficial effects of these substances are very limited. Recent progress in delivering polyphenols to the targeted tissues revealed new possibilities for the use of polymeric nanoparticles in increasing the efficiency and reducing the degradability of natural polyphenols. This review focuses on the effects of different natural polyphenolic substances, especially resveratrol, quercetin, curcumin, and cherry extracts, and their ability to bind to polymeric nanoparticles, and summarizes the effects of polyphenol-loaded nanoparticles, mainly in the cardiovascular system

    Targeted Strategy in Lipid-Lowering Therapy

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    Dyslipidemia is characterized by a diminished lipid profile, including increased level of total cholesterol and low-density lipoprotein cholesterol (LDL-c) and reduced level of high-density lipoprotein cholesterol (HDL-c). Lipid-lowering agents represent an efficient tool for the prevention or reduction of progression of atherosclerosis, coronary heart diseases and metabolic syndrome. Statins, ezetimibe, and recently proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are the most effective and used drugs in clinical lipid-lowering therapy. These drugs are mainly aimed to lower cholesterol levels by different mechanisms of actions. Statins, the agents of the first-line therapy&mdash;known as 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors&mdash;suppress the liver cholesterol synthesis. Ezetimibe as the second-line therapy can decrease cholesterol by inhibiting cholesterol absorption. Finally, the PCSK9 inhibitors act as an inducer of LDL excretion. In spite of their beneficial lipid-lowering properties, many patients suffer from their serious side effects, route of administration, or unsatisfactory physicochemical characteristics. Clinical demand for dose reduction and the improvement of bioavailability as well as pharmacodynamic and pharmacokinetic profile has resulted in the development of a new targeted therapy that includes nanoparticle carriers, emulsions or vaccination often associated with another more subtle form of administration. Targeted therapy aims to exert a more potent drug profile with lipid-lowering properties either alone or in mutual combination to potentiate their beneficial effects. This review describes the most effective lipid-lowering drugs, their favorable and adverse effects, as well as targeted therapy and alternative treatments to help reduce or prevent atherosclerotic processes and cardiovascular events
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