Induction of radical scavenging ability and suppression of lipid peroxidation in rat liver microsomes following whole-body, low-dose X-irradiation

Purpose: To investigate changes in radical scavenging ability and lipid peroxidation in liver microsomal membranes and cooperative suppression of lipid peroxidation by microsomal and cytosolic radical scavengers, 24 h after whole-body, low-dose X-irradiation of rats.Materials and methods: Male Wistar rats were irradiated with 1 – 50 cGy of X-rays. Liver microsomal radical scavenging ability was determined using the trapping ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH), a stable free radical. Microsomal α-tocopherol (Vit.E) content was determined using an electrochemical detector. Microsomal glutathione peroxidase (GPx) activity was determined as the consuming rate of NADPH. Microsomal lipid peroxidation was determined by the thiobarbituric acid method.Results: Low molecular weight radical scavenging ability of rat liver microsomes increased 24 h after whole-body, low-dose X-irradiation when α-tocopherol was included, showing a maximum level at 5 – 10 cGy. Microsomal GPx activity also increased 24 h aft...