Effects Of Omega-3 Fatty Acids On Endothelium-dependent Relaxation In Hypercholesterolemic Rabbits [efeito Dos Acidos Graxos Omega-3 Sobre O Relaxamento-dependente Do Endotelio Em Coelhos Hipercolesterolemicos]

Purpose: To study the effect of omega-3 fatty acid on endothelium-dependent relaxation, total plasma cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides levels as well as, the malondialdehyde (MDA) content of the LDL particles and arterial wall. Methods: Fourteen male rabbits were randomly assigned to hypercholesterolemic and omega-3 groups. The dose of omega-3 fatty acid utilized was 300 g/kg/day during 15 days. All rabbits were fed a diet supplemented with cholesterol (0.5%) and coconut oil (2%) for four weeks. At the end of the experiment the animals were killed and the aorta removed for measurement of MDA content and the endothelium-dependent relaxation studies. Total plasma cholesterol, VLDL-cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides was measured by enzymatic kits. MDA was also measured in natives and oxidized LDL and arterial wall. Results: Cholesterol and VLDL-cholesterol were increased significantly in the omega-3 treated animals. The triglyceride level was significantly reduced (p < 0.05). The MDA content was increased in the LDL particles and in the arterial wall (p < 0.05). Endothelium-dependent relaxation was significantly reduced (p < 0.05). Conclusion: Omega-3 fatty acid impairs the endothelium-dependent relaxation when administered to cholesterol fed rabbits, increased the cholesterol and reduces the triglycerides plasma levels. 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