Avaliação do estresse oxidativo nos tecidos cardíaco, hepático, esquelético e renal na deficiência em tiamina

Abstract

Thiamine (Vitamin B1) is known to have a major role in some body functions, once synthesized, originates important metabolic enzymes, whereas its absence can cause numerous unbalances at tissue and cellular levels, example being oxidative stress and associated cellular structure damage which can compromise integrity. In the first part of this study, rats were submitted to a thiamine deficient diet for 35 days and the antioxidant systems activity and expression as well as the lipid peroxidation levels for the liver, kidney and skeletal muscles were evaluated. The results demonstrated that in the liver the activity and expression of catalase, superoxide dismutase and gluthatione peroxidase did not differ between controls and thiamine deficient rats. In the kidney, catalase activity was decreased in thiamine deficient rats when compared to controls, however no change happened in lipid peroxidation between controls and thiamine deficient rats. The skeletal muscle was the organ that presented the most changes in antioxidant system, yet no change was verify in lipid peroxidation. Catalase activity is increased and the expression was decreased in skeletal muscle of thiamine deficient when compared to controls rats. On the second part of this study, the thiamine deficient group was submitted to a 5 day thiamine reposition diet to evaluate the improvement of heart oxidative stress state. Catalase activity as well as lipid peroxidation levels, once altered in thiamine deficient rats, returned to same levels encountered in control rats. In this study is demonstrated alterations in activity and expression of enzymatic antioxidants systems as a mechanism to maintain homeostasis of different organs and to avoid lipid peroxidation in model of thiamine deficiency. Additionally, thiamine reposition reverts the oxidative stress levels in thiamine deficient aminal hearts.