Effects of iron and copper supplementation on the formation of thiobarbituric acid-reactive substances and phosphatidylcholine hydroperoxide in the livers of iron- and copper-deficient rats

Free radicals and lipid peroxide formation are related to tissue damage. This damage is thought to be associated with various diseases. To accurately assess the degree of lipid hydroperoxidation in biological materials, three different thiobarbituric acid (TBA) assay methods and the measurement of phosphatidylcholine hydroperoxide (PCOOH) by the chemiluminescence-HPLC (CL-HPLC) method were compared. Iron and copper deficiencies in rats reduced the contents of these metals. The addition of iron and copper to liver homogenates produced dose-dependent increases and decreases in TBARS, respectively. TBARS measured by the Shinnhuber method slightly increased with the addition of copper. The measurement of PCOOH was less affected by the addition of these metals. TBARS did not reflect lipid peroxidation when different concentrations of metals were present in the samples. The TBARS level is thus not a suitable marker for the assess of lipid peroxidation. PCOOH, accumulated as a primary peroxidation product from membrane phospholipids in the liver, was found to be a more appropriate marker for the estimating hepatic lipid peroxidation in the iron- and/or copper-deficient condition.