Oxidative stress in heart tissue of hyperthyroid and iron supplemented rats

This study was designed to investigate the effect of hyperthyroidism and/or iron supplementation on cardiac oxidative stress parameters-the lipid pero xidation end product glutathione (GSH), glutathione peroxidase (GSH-Px), an d superoxide dismutase (CuZnSOD) - in rats, In plasma, ferritin as an indic ator of iron status and glutamate oxaloacetate transaminase (GOT) as an ind icator of damage to the heart tissue were analyzed. Our findings show that hyperthyroidism increased lipooxidative damage as reflected by higher lipid peroxidation end product levels and elevated antioxidant defense parameter s-GSH and GSH-Px. Iron supplementation per se does not affect oxidative str ess parameters studied in the euthyroid state. Although iron increased lipi d peroxidation in the hyperthyroid state, this effect was less than that se en in euthyroidism. Iron supplementation to hyperthyroid rats significantly lowered plasma ferritin levels, suggesting increased iron elimination with consequently reduced oxidative stress.