LA DEFICIENCIA EN VITAMINA A AFECTA LA MORFOLOGÍA DE LA ARTERIA AORTA

GATICA L; DOMINGUES S; OLIVEROS L; GIMENEZ M; FORNES M W

Mar del Plata- Buenos Aires (Argentina)

Congreso; Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2006

SAIC

LA DEFICIENCIA EN VITAMINA A AFECTA LA MORFOLOGÍA DE LA ARTERIA AORTA. Gatica Laura, Domínguez Susana, Oliveros Liliana, Giménez Ma. Sofía, Fornés Miguel. M. Previously, we informed that vitamin A deficiency promotes oxidative stress, increases the expression of markers of inflammation, and alters the lipid metabolism in aorta. Here we study the effect of dietary vitamin A deprivation on the expression levels of TNF-alpha and TGF-beta1, cytokines involved in inflammation and increased vascular permeability, and related to neointima formation, respectively, and the possible impact of such factors and additional markers previously evaluated for us on the histoarchitecture of aorta. We found increased expression levels of TNF-alpha mRNA and TGF-beta1 protein in aortas of vitamin A- deficient rats. Examination of the intimal layer by light microscopy showed the presence of an irregular surface in aortas of animals fed with a vitamin A-free diet. Transmission electron microscopy (TEM) studies showed the presence of large vacuoles and multivesicular bodies (MVB) along the endothelium of aorta of vitamin A- deficient group. These organelles were also found in the subendothelial space, which appeared enlarged and characterized by an apparent increase in the density of fibrils of collagen. In vitamin A-deficient aortas, the histological organization of internal elastic lamina (IEL) was different from control. Furthermore, vitamin A deficiency was associated to the presence of small vesicles in the medial layer. These results supports evidence about morphological alterations in the intimal and medial layer of aorta from vitamin A-deficient rats and suggests that those changes may be associated to the increased TNF-alpha and TGF-beta1 expressions and promoted by the oxidative stress and disturbances in lipid metabolism induced by dietary vitamin A deprivation.