Abstract
Marfan syndrome (MFS) is associated with progressive aortic dilatation and endothelial dysfunction that lead to early acute dissection and rupture of the aorta and sudden death. Alteration in fatty acid (FA) metabolism can stimulate nitric oxide (NO) overproduction which increases the activity of the inducible form of NO synthase (iNOS) that is involved in endothelial dysfunction. We evaluated the participation of FA in the formation of thoracic aneurysms in MFS and its relation to the iNOS. Oleic acid (OA), iNOS, citrulline, nitrates and nitrites, TGF-β1, TNF-α, monounsaturated FA and NO synthase activity were significantly increased (p<0.05) in tissue from the aortas of MFS. Saturated FA, eNOS and HDL were significantly decreased (p<0.05). Arachidonic acid, delta-9 desaturase tended to increase and histological examination showed an increase in cystic necrosis, elastic fibers and collagen in MFS. The increase in OA contributes to the altered pathway of iNOS, which favors endothelial dysfunction and formation of the aortic aneurysms in MFS.