Biologia dos elementos vestigiais na aterosclerose

The aim of this work was to study how the alterations of the minor and trace element contents can be related to clinical aspects and metabolic imbalances of atherosclerosis. The minor and trace elemental contents of various human tissues were determined to infer their role in the biochemical processes connected with the pathology. These elemental variations were studied in brain, blood (serum and packed blood cells) and artery samples originated from individuals affected and not affected by the disease. PIXE and Nuclear Microprobe analysis were applied to the determination of the elemental contents in the various tissues. These analytical techniques are based on X-ray induced by accelerated charged particles. It must be emphasized that Nuclear Microprobe has micro-analytical capabilities. Depending on the sample preparation method applied, up to 12 elements were determined quantitatively both by PIXE and Nuclear Microprobe, i.e., P, S, C1, K, Ca, Mn, Fe, Cu, Zn, Se, Rb, Sr and Pb, in the brain, blood and artery wall samples. Major alterations were verified for the trace element contents in all the tissues analyzed, with the disease progression. For the 5 brain regions studied, nucleus caudatus, putamen and substancia nigra were the most affected structures. Fe, Cu and Zn showed to be related with the atherogenesis in all tissues studied and can also be linked to the tissue specific biochemical mechanisms. Other elements can be associated to Fe, Cu and Zn, depending on the characteristic tissue biochemistry. For all the brain structures studied, the observed variations of Mn and Se levels were associated to Zn. This relationship may indicate a response of the tissue to injury or a failure in Fe and Cu homeostasis due to atherosclerosis. In serum, was noticed a decrease in the concentration levels of Fe while Cu levels were enhanced. A significant correlation was found between the observed variations of Fe and Cu, and the lipoprotein HDL (high Density Lipids) levels. So far, HDL, as well as other lipoprotein levels, constitute a risk factor to atherosclerosis. As blood constitutes an excellent tool in diagnostic, the evaluation of serum Fe and Cu concentrations..Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga