Membrane effects of the n-3 fish oil fatty acids, which prevent fatal ventricular arrhythmias.
ABSTRACT Fish oil fatty acids are known to exert beneficial effects on the heart and vascular systems. We have studied the membrane effects on ion channel conductance by the n-3 fish oil fatty acids that account for these beneficial effects. We have confirmed that these fatty acids prevent fatal cardiac arrhythmias in a reliable dog model of sudden cardiac death. This finding was followed by experiments indicating that the n-3 fatty acids electrically stabilize heart cells and do so largely through modulation of the fast voltage-dependent Na(+) currents and the L-type Ca(2+) channels in a manner, which makes the heart cells resistant to arrhythmias. Others and we have demonstrated that these membrane effects on the heart can prevent fatal cardiac arrhythmias in humans.
- SourceAvailable from: Bernhard Rauch[Show abstract] [Hide abstract]
ABSTRACT: The effects of supplementation of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on prevalence and severity of depression were evaluated in patients after a myocardial infarction. A cross-sectional evaluation (posttest-only design) within the prospective, randomized, controlled, multicenter OMEGA trial was performed in patients after myocardial infarction at 12 months' follow-up (N = 2,081; age, mean = 64 years; men, 76.7%; women, 21.8%) from April 2005 to June 2007. Patients received supplementation with ethyl esters 90 (460-mg EPA and 380-mg DHA) or placebo for 12 months. Depression was assessed with the Beck Depression Inventory-II (BDI-II); a BDI-II cutoff score of ≥ 14 was used as diagnosis of depression. When the total population was evaluated, no effects of EPA/DHA supplementation on depressive symptoms according to BDI-II score (mean [SD]) could be demonstrated: EPA/DHA (n = 1,046), 7.1 (6.9); placebo (n = 1,035), 7.1 (7.0); P = .7. The post hoc analyses of depressed patients with and without antidepressants revealed a tendency toward an antidepressant effect in patients with EPA/DHA supplementation as monotherapy: EPA/DHA (n = 125), 19.4 (5.8); placebo (n = 113), 19.9 (5.1); P = .07. However, in depressed patients with EPA/DHA supplementation as adjunctive to conventional antidepressants, a clinically relevant antidepressant effect was demonstrated: EPA/DHA (n = 33), 20.9 (7.1); placebo (n = 29), 24.9 (8.5); P < .05. EPA/DHA supplementation in the total sample of patients after myocardial infarction had no effect on depressive symptoms. The clinically relevant antidepressant effect in the subgroup of depressed patients with EPA/DHA supplementation as adjunctive to conventional antidepressants that was revealed in the post hoc analysis might provide a basis for a controlled, prospective trial of omega-3 augmentation of antidepressants in patients after myocardial infarction. ClinicalTrials.gov identifier: NCT00251134.The Journal of Clinical Psychiatry 11/2013; 74(11):e1037-e1045. DOI:10.4088/JCP.13m08453
- [Show abstract] [Hide abstract]
ABSTRACT: Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice with growing prevalence in developed countries. Several medical and interventional therapies, such as atrial specific drugs and pulmonary vein isolation, have demonstrated prevention of recurrences. However, their suboptimal long-term success and significant rate of secondary effects have led to intensive research in the last decade focused on novel alternative and supplemental therapies. One such candidate is polyunsaturated fatty acids (PUFAs). Because of their biological properties, safety, simplicity, and relatively cheap cost, there is a special clinical interest in omega-3 PUFAs as a possible antiarrhythmic agent. Obtained from diets rich in fish, they represent one of the current supplemental therapies. At the cellular level, an increasing body of evidence has shown that n-3 PUFAs exert a variety of effects on cardiac ion channels, membrane dynamic properties, inflammatory cascade, and other targets related to AF prevention. In this article, we review the current basic and clinical evidence pertinent to n-3 PUFAs in AF treatment and prevention. We also discuss controversial outcomes among clinical studies and propose specific subsets of AF patients who will benefit most from n-3 PUFAs.Frontiers in Physiology 09/2012; 3:370. DOI:10.3389/fphys.2012.00370
- [Show abstract] [Hide abstract]
ABSTRACT: The aim of this study was to assess relationships between the fatty acid contents of plasma and erythrocyte phospholipids and those in liver, heart, brain, kidney and quadriceps muscle in rats. To obtain a wide range of tissue omega-3 (n-3) long chain polyunsaturated fatty acids (LCPUFA) we subjected weanling rats to dietary treatment with the n-3 LCPUFA precursor, alpha linolenic acid (ALA, 18:3 n-3) for 3 weeks. With the exception of the brain, we found strong and consistent correlations between the total n-3 LCPUFA fatty acid content of both plasma and erythrocyte phospholipids with fatty acid levels in all tissues. The relationships between eicosapentaenoic acid (EPA, 20:5 n-3) and docosapentaenoic acid (DPA, 22:5 n-3) content in both blood fractions with levels in liver, kidney, heart and quadriceps muscle phospholipids were stronger than those for docosahexaenoic acid (DHA, 22:6 n-3). The strong correlations between the EPA+DHA (the Omega-3 Index), total n-3 LCPUFA and total n-3 PUFA contents in both plasma and erythrocyte phospholipids and tissues investigated in this study suggest that, under a wide range of n-3 LCPUFA values, plasma and erythrocyte n-3 fatty acid content reflect not only dietary PUFA intakes but also accumulation of endogenously synthesised n-3 LCPUFA, and thus can be used as a reliable surrogate for assessing n-3 status in key peripheral tissues.Prostaglandins Leukotrienes and Essential Fatty Acids 04/2012; 88(1). DOI:10.1016/j.plefa.2012.04.005