Effects of Arsenic (AsIII) on Lipid Peroxidation, Glutathione Content and Antioxidant Enzymes in Growing Pigs

This experiment was conducted to investigate the effect of arsenic ($As^{III}$) on lipid peroxidation, glutathione content and antioxidant enzymes in growing pigs. Ninety-six Duroc-Landrace-Yorkshire crossbred growing pigs (48 barrows and 48 gilts, respectively) were randomly assigned to four groups and each group was randomly assigned to three pens (four barrows and four gilts). The four groups received the same corn-soybean basal diet which was supplemented with 0, 10, 20, 30 mg/kg As respectively. Arsenic was added to the diet in the form of $As_2O_3$. The experiment lasted for seventy-eight days after a seven-day adaptation period. Malondialdehyde (MDA) levels, glutathione (GSH) contents and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) activities were analyzed in serum, livers and kidneys of pigs. The results showed that pigs treated with 30 mg As/kg diet had a decreased average daily gain (ADG) (p<0.05) and an increased feed/gain ratio (F/G) (p<0.05) compared to the controls. The levels of MDA significantly increased (p<0.05), and the contents of GSH and the activities of SOD, CAT, GPx, GR and GST significantly decreased (p<0.05) in the pigs fed 30 mg As/kg diet. The results indicated that the mechanism of arsenic-induced oxidative stress in growing pigs involved lipid peroxidation, depletion of glutathione and decreased activities of some enzymes, such as SOD, CAT, GPx, GR and GST, which are associated with free radical metabolism.