Effects of dietary antioxidants on lipid peroxide formation in animal tissues after whole-body irradiation

SummaryRates of lipid peroxidation in mouse-liver homogenates increased linearly with dose 24 hours after whole-body irradiation (500–2000 rads), and reached a maximum 3 days after irradiation. Smaller increases in the rates of peroxidation occurred in heart, kidney or spleen homogenates.Vitamin E supplementation of the diet depressed the rate of lipid peroxidation in liver, heart, spleen and kidney homogenates after irradiation with 1000–2000 rads. Hydroperoxide and malonaldehyde increased significantly in spleen lipids after irradiation but much smaller changes occurred in heart or liver lipids. Dietary vitamin E inhibited increase of malonaldehyde but had little effect on hydroperoxide increases. Dietary BHT (2,6-di-tert butyl-p-cresol) was less effective than vitamin E but depressed the rate of peroxidation in liver homogenate and microsomal fraction.In the liver microsomal fraction, the maximum rate of peroxidation and minimum antioxidant concentration occurred concurrently.Tissue and subcellular antioxidant concentrations are considered to play a major role in regulating the rate of lipid peroxidation after irradiation.