%0 Journal Article
%T The Role of Oxidative Stress on the Pathogenesis of Graves' Disease
%A Milo£¿ £¿arkovi£¿
%J Journal of Thyroid Research
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/302537
%X Graves' disease is a most common cause of hyperthyroidism. It is an autoimmune disease, and autoimmune process induces an inflammatory reaction, and reactive oxygen species (ROSs) are among its products. When balance between oxidants and antioxidants is disturbed, in favour of the oxidants it is termed ¡°oxidative stress¡± (OS). Increased OS characterizes Graves' disease. It seems that the level of OS is increased in subjects with Graves' ophthalmopathy compared to the other subjects with Graves' disease. Among the other factors, OS is involved in proliferation of orbital fibroblasts. Polymorphism of the 8-oxoG DNA N-glycosylase 1 (hOGG1) involved in repair of the oxidative damaged DNA increases in the risk for developing Grave's disease. Treatment with glucocorticoids reduces levels of OS markers. A recent large clinical trial evaluated effect of selenium on mild Graves' ophthalmopathy. Selenium treatment was associated with an improved quality of life and less eye involvement and slowed the progression of Graves' orbitopathy, compared to placebo. 1. Introduction Graves' disease is a most common cause of hyperthyroidism in iodine sufficient areas [1]. It is characterized by diffuse goitre and hyperthyroidism. Graves' orbitopathy represents orbit involvement and is clinically relevant in about half of the patients with the Graves' disease. In 3 to 5% of the patients, orbitopathy is severe [2]. Graves' disease is an autoimmune disease characterized by the presence of the serum autoantibodies. TSH receptor antibody represents the major autoantibody in Graves' disease [3]. Autoimmune process induces an inflammatory reaction and reactive oxygen species (ROSs) are among its products. ROSs are formed as normal metabolic products and are important in normal cellular functioning, but their production can be increased under pathological conditions and cause damage [4, 5]. Therefore, a large number of antioxidant systems act as protective mechanism. Among them are superoxide dismutase which catalyses dismutation of superoxide to peroxide, catalase which catalyses the decomposition of hydrogen peroxide to water and oxygen, while glutathione peroxidise which reduces lipid hidroperoxides while simultaneously oxidizing glutathione [6]. Situation in which balance between oxidants and antioxidants is disturbed in favour of the oxidants is termed ¡°oxidative stress¡± (OS) [4]. 2. Oxidative Stress and the Thyroid Gland Synthesis of thyroid hormones requires formation of the hydrogen peroxide, a highly reactive oxidant. Hydrogen peroxide and oxidized iodine are immediately
%U http://www.hindawi.com/journals/jtr/2012/302537/