Effects of α-ketoglutarate on antioxidants and lipid peroxidation products in rats treated with ammonium acetate

The effects of a-ketoglutarate (a-KG) on hyperammonemia induced by ammonium acetate were studied biochemically in experimental rats. The levels of circulatory urea and non-protein nitrogen increased significantly in rats treated with ammonium acetate and decreased significantly in rats treated with alpha-KG and ammonium acetate. In liver and kidney tissues, similar patterns of alterations across groups were observed in the levels of thiobarbituric acid-reactive substances and lipid profile variables (free fatty acids, triacylglycerols, phospholipids, and cholesterol). Further, enzymatic (superoxide dismulase, catalase, and glutathione peroxidase) and non-enzymatic (reduced glutathione) antioxidants in both tissues decreased significantly in rats treated with ammonium acetate and increased significantly in rats treated with a-KG and ammonium acetate. The biochemical alterations during a-KG treatment might have been due to 1) the detoxification of excess ammonia, 2) participation in the non-enzymatic oxidative decarboxylation during hydrogen peroxide decomposition, and 3) enhancement of the proper metabolism of fats that could suppress oxygen radical generation and thus prevent lipid peroxidative damages in rats. (C) Elsevier Science Inc. 2002.