Cardiovascular Activity https://greenmedinfo.com/category/keywords/Cardiovascular%20Activity en A lipid peroxidation product of DHA exerts anti-arrhythmia properties post heart attack in mice. It challenges the paradigm that all lipid peroxidation products are unconditionally toxic. https://greenmedinfo.com/article/lipid-peroxidation-product-dha-exerts-anti-arrhythmia-properties-post-heart-at PMID:  Free Radic Biol Med. 2015 Sep ;86:269-78. Epub 2015 Apr 21. PMID: 25911196 Abstract Title:  Nonenzymatic lipid mediators, neuroprostanes, exert the antiarrhythmic properties of docosahexaenoic acid. Abstract:  Neuroprostanes are lipid mediators produced by nonenzymatic free radical peroxidation of docosahexaenoic acid (DHA). DHA is associated with a lower atherosclerosis risk, suggesting a beneficial role in cardiovascular diseases. The aim of this study was to investigate the influence of DHA peroxidation on its potentially antiarrhythmic properties (AAP) in isolated ventricular cardiomyocytes and in vivo in post-myocardial infarcted mice. Calcium imaging and biochemical experiments indicate that cardiac arrhythmias induced by isoproterenol are associated with Ca(2+) leak from the sarcoplasmic reticulum after oxidation and phosphorylation of the type 2 ryanodine receptor (RyR2) leading to dissociation of the FKBP12.6/RyR2 complex. Both oxidized DHA and 4(RS)-4-F4t-NeuroP prevented cellular arrhythmias and posttranslational modifications of the RyR2 leading to a stabilized FKBP12.6/RyR2 complex. DHA per se did not have AAP. The AAP of 4(RS)-4-F4t-NeuroP was also observed in vivo. In this study, we challenged the paradigm that spontaneously formed oxygenated metabolites of lipids are undesirable as they are unconditionally toxic. This study reveals that the lipid mediator 4(RS)-4-F4t-neuroprostane derived from nonenzymatic peroxidation of docosahexaenoic acid can counteract such deleterious effects through cardiac antiarrhythmic properties. Our findings demonstrate 4(RS)-4-F4t-NeuroP as a mediator of the cardioprotective AAP of DHA. This discovery opens new perspectives for products of nonenzymatic oxidizedω3 polyunsaturated fatty acids as potent mediators in diseases that involve ryanodine complex destabilization such as ischemic events. <p><a href="https://greenmedinfo.com/article/lipid-peroxidation-product-dha-exerts-anti-arrhythmia-properties-post-heart-at" target="_blank">read more</a></p> https://greenmedinfo.com/article/lipid-peroxidation-product-dha-exerts-anti-arrhythmia-properties-post-heart-at#comments Arrhythmias: Cardiac DHA (Docosahexaenoic Acid) Myocardial Infarction Omega-3 Fatty Acids Anti-Arrhythmia Agents Cardioprotective Cardiovascular Activity cardiovascular health Heart Attacks Omega-3 Fatty Acid Metabolism Animal Study Mon, 29 Jul 2019 19:03:00 +0000 greenmedinfo 192183 at https://greenmedinfo.com A lipid peroxidation product of DHA regulates mitochondrial homeostasis and reduces apoptosis to reduce reperfusion damage in a rat model of ischemic reperfusion. https://greenmedinfo.com/article/lipid-peroxidation-product-dha-regulates-mitochondrial-homeostasis-and-reduces PMID:  Free Radic Biol Med. 2017 01 ;102:229-239. Epub 2016 Dec 5. PMID: 27932075 Abstract Title:  Non-enzymatic oxidized metabolite of DHA, 4(RS)-4-F-neuroprostane protects the heart against reperfusion injury. Abstract:  Acute myocardial infarction leads to an increase in oxidative stress and lipid peroxidation. 4(RS)-4-F-Neuroprostane (4-F-NeuroP) is a mediator produced by non-enzymatic free radical peroxidation of the cardioprotective polyunsaturated fatty acid, docosahexaenoic acid (DHA). In this study, we investigated whether intra-cardiac delivery of 4-F-NeuroP (0.03mg/kg) prior to occlusion (ischemia) prevents and protects rat myocardium from reperfusion damages. Using a rat model of ischemic-reperfusion (I/R), we showed that intra-cardiac infusion of 4-F-NeuroP significantly decreased infarct size following reperfusion (-27%) and also reduced ventricular arrhythmia score considerably during reperfusion (-41%). Most notably, 4-F-NeuroP decreased ventricular tachycardia and post-reperfusion lengthening of QT interval. The evaluation of the mitochondrial homeostasis indicates a limitation of mitochondrial swelling in response to Caby decreasing the mitochondrial permeability transition pore opening and increasing mitochondria membrane potential. On the other hand, mitochondrial respiration measured by oxygraphy, and mitochondrial ROS production measured with MitoSox red® were unchanged. We found decreased cytochrome c release and caspase 3 activity, indicating that 4-F-NeuroP prevented reperfusion damages and reduced apoptosis. In conclusion, 4-F-NeuroP derived from DHA was able to protect I/R cardiac injuries by regulating the mitochondrial homeostasis. <p><a href="https://greenmedinfo.com/article/lipid-peroxidation-product-dha-regulates-mitochondrial-homeostasis-and-reduces" target="_blank">read more</a></p> https://greenmedinfo.com/article/lipid-peroxidation-product-dha-regulates-mitochondrial-homeostasis-and-reduces#comments DHA (Docosahexaenoic Acid) Myocardial Infarction Omega-3 Fatty Acids Tachycardia Anti-Apoptotic Cardioprotective Cardiovascular Activity Lipid Peroxidation Mitochondria Omega-3 Fatty Acid Metabolism Animal Study Mon, 29 Jul 2019 18:56:58 +0000 greenmedinfo 192180 at https://greenmedinfo.com In short-term trials, vitamin C supplementation lowered blood pressure. https://greenmedinfo.com/article/short-term-trials-vitamin-c-supplementation-lowered-blood-pressure PMID:  Am J Clin Nutr. 2012 Apr 4. Epub 2012 Apr 4. PMID: 22492364 Abstract Title:  Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials. Abstract:  BACKGROUND: In observational studies, increased vitamin C intake, vitamin C supplementation, and higher blood concentrations of vitamin C are associated with lower blood pressure (BP). However, evidence for blood pressure-lowering effects of vitamin C in clinical trials is inconsistent.Objective: The objective was to conduct a systematic review and meta-analysis of clinical trials that examined the effects of vitamin C supplementation on BP. DESIGN: We searched Medline, EMBASE, and Central databases from 1966 to 2011. Prespecified inclusion criteria were as follows: 1) use of a randomized controlled trial design; 2) trial reported effects on systolic BP (SBP) or diastolic BP (DBP) or both; 3) trial used oral vitamin C and concurrent control groups; and 4) trial had a minimum duration of 2 wk. BP effects were pooled by random-effects models, with trials weighted by inverse variance. RESULTS: Twenty-nine trials met eligibility criteria for the primary analysis. The median dose was 500 mg/d, the median duration was 8 wk, and trial sizes ranged from 10 to 120 participants. The pooled changes in SBP and DBP were -3.84 mm Hg (95% CI: -5.29, -2.38 mm Hg; P&lt;0.01) and -1.48 mm Hg (95% CI: -2.86, -0.10 mm Hg; P = 0.04), respectively. In trials in hypertensive participants, corresponding reductions in SBP and DBP were -4.85 mm Hg (P&lt;0.01) and -1.67 mm Hg (P = 0.17). After the inclusion of 9 trials with imputed BP effects, BP effects were attenuated but remained significant.Conclusions: In short-term trials, vitamin C supplementation reduced SBP and DBP. Long-term trials on the effects of vitamin C supplementation on BP and clinical events are needed. https://greenmedinfo.com/article/short-term-trials-vitamin-c-supplementation-lowered-blood-pressure#comments Hypertension Vitamin C Hypotensive Blood Pressure Blood Pressure: High Cardiovascular Activity cardiovascular health Meta Analysis Vitamin C Sun, 15 Apr 2012 20:28:39 +0000 greenmedinfo 74348 at https://greenmedinfo.com