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O ferro e as anemias ferroprivas
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| PPG_11884 | 2.86 MB | Adobe PDF |
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Resumo(s)
O ferro é um composto inorgânico essencial para as diversas funções celulares, tais
como, a síntese de DNA, o metabolismo energético e o transporte de oxigénio.
Adicionalmente funciona como cofator em muitos processos enzimáticos da cadeia
respiratória mitocondrial (Medeiros, 2006).
O ferro utilizado pelo organismo tem duas fontes principais: a dieta e a reciclagem das
hemácias, sendo que o ferro da dieta é encontrado sob duas formas: orgânica e
inorgânica, já o proveniente da reciclagem das hemácias encontra-se na forma orgânica.
O ferro necessário para a eritropoiese é obtido através de um sistema eficiente de
reciclagem no qual os macrófagos fagocitam os eritrócitos, degradando a hemoglobina e
exportando o ferro para a circulação para ser novamente utilizado (Carvalho et al.,
2006).
Apesar da importância do ferro a nível do funcionamento dos organismos, este é um
pode ser tóxico através quando exerce a sua ação catalítica na produção de radicais
livres de oxigénio. Assim sendo, os seres vivos desenvolveram sistemas de regulação do
metabolismo do ferro, quer a nível de regulação do metabolismo intracelular quer ao
nível sistémico, garantindo que os níveis de ferro não sejam deficientes nem em
excesso. As consequências do desequilíbrio do metabolismo do ferro são bem
conhecidas clinicamente, se por um lado a deficiência de ferro se manifesta
clinicamente através da anemia por outro lado o excesso origina, por exemplo, a
hemocromatose hereditária, podendo levar à lesão tecidular em vários órgãos, com
manifestações como a cirrose hepática, diabetes, hipogonadismo, artrite ou cardiopatia
(Cançado e Chiattone, 2002).
The iron is an essential inorganic compound for diverse cellular functions such as DNA synthesis, energy metabolism and transport of oxygen. Additionally it acts as a cofactor in many enzymatic processes of the mitochondrial respiratory chain (Medeiros, 2006). The iron used in the body has two main sources: the diet and recycling of red blood cells, wherein the dietary iron is found in two forms: organic and inorganic, already from the recycling of erythrocytes is in organic form. The iron required for erythropoiesis is obtained by an efficient recycling system in which macrophages phagocytose erythrocytes, hemoglobin and exporting degrading the iron into the circulation to be used again (Carvalho et al., 2006). Despite the importance of iron in the operation of the bodies, this is can be toxic when carrying through their catalytic action on the production of oxygen free radicals. Thus, living beings developed iron metabolism regulation systems, both in terms of regulation of intracellular metabolism either at the systemic level, ensuring that iron levels are not disabled or in excess. The iron metabolism disequilibrium consequences are well known clinically, is for iron deficiency side clinically manifested by anemia moreover excess originates, for example, hereditary hemochromatosis, can lead to tissue damage in several organs, with manifestations such as cirrhosis, diabetes, hypogonadism, arthritis or disease (Cançado and Chiattone, 2002).
The iron is an essential inorganic compound for diverse cellular functions such as DNA synthesis, energy metabolism and transport of oxygen. Additionally it acts as a cofactor in many enzymatic processes of the mitochondrial respiratory chain (Medeiros, 2006). The iron used in the body has two main sources: the diet and recycling of red blood cells, wherein the dietary iron is found in two forms: organic and inorganic, already from the recycling of erythrocytes is in organic form. The iron required for erythropoiesis is obtained by an efficient recycling system in which macrophages phagocytose erythrocytes, hemoglobin and exporting degrading the iron into the circulation to be used again (Carvalho et al., 2006). Despite the importance of iron in the operation of the bodies, this is can be toxic when carrying through their catalytic action on the production of oxygen free radicals. Thus, living beings developed iron metabolism regulation systems, both in terms of regulation of intracellular metabolism either at the systemic level, ensuring that iron levels are not disabled or in excess. The iron metabolism disequilibrium consequences are well known clinically, is for iron deficiency side clinically manifested by anemia moreover excess originates, for example, hereditary hemochromatosis, can lead to tissue damage in several organs, with manifestations such as cirrhosis, diabetes, hypogonadism, arthritis or disease (Cançado and Chiattone, 2002).
Descrição
Palavras-chave
Ferro Homeostasia do ferro Deficiência de ferro Anemia ferropriva Iron Iron homeostasis Iron deficiency Iron deficiency anemia