Increased oxidative stress is the consequence of either enhanced reactive oxygen species (ROS) production or attenuated ROS scavenging capacity, resulting in tissue damage that in most instances is assessed by the measurement of lipid peroxides. In the current study, diabetes-induced lipid peroxidation in rat liver microsomal membranes was investigated by Fourier transform infrared (FT-IR) spectroscopy at different temperatures. The olefinic (=CH) band at 3012 cm(-1) was used to probe diabetes-induced lipid peroxidation. The intensity and area values of this band of diabetic samples were found to be increased significantly (P < 0.05) compared with nondiabetic samples. The increase in olefinic band intensity is attributed mainly to the lipid peroxidation end products. The results of the FT-IR study were found to be in agreement with biochemical studies that revealed a significant increase in malondialdehyde levels of diabetic samples compared with control samples (P < 0.05) using the thiobarbituric acid test. (c) 2005 Elsevier Inc. All rights reserved.