Potential oxidative stress due to Pb exposure

Abstract

The hazards of Pb exposure has been a topic of concern for many years. This research was developed to investigate the possibility of Pb induced oxidative stress. The research objectives were to observe Pb induced lipid peroxidation and Pb induced increases in oxidation of glutathione in K562 myelogenous leukemia cells at low Pb levels. The approach consisted of incubating K562 cells in solutions of 0, 300, and 700 ppb Pb dissolved in RPMI cell medium for a total of 96 hours. After this period of incubation, aliquots of cells were taken, placed in clean medium, and incubated for 96 hours. Samples were taken at 24 and 96 hours of Pb exposure, and at 96 hours after cessation of Pb exposure, then subsequently assayed for lipid peroxidation and glutathione levels. Lipid peroxidation was determined by the detection of malondialdehyde (MDA) spectrophotometrically at 535nm by the Thiobarbituric acid (TBA) assay, while oxidized and reduced glutathione levels were determined spectrophotometrically at 412 nm. Results showed no change in MDA levels in treated cells as compared to the control. The GSH: GSSG ratios were significantly greater for treated cells at 96 hours of exposure as compared to the controls, indicating a possible compensatory response.