The Cell Membrane as a Biosensor of Oxidative Stress Induced by Radiation Exposure: A Multiparameter Investigation

Abstract

The role of biological membranes as a target in biological radiation damage remains unclear. The present study investigates how the biochemical and biophysical properties of a simple biological model, i.e. human erythrocyte membranes, are altered after exposure to relatively low doses of (60)Co gamma rays. Lipid peroxidation increased in the hours after radiation exposure, based on measurements of MDA and on the lipid peroxidation index after parinaric acid incorporation. Protein carbonyl content also increased rapidly after radiation exposure. An imbalance between the radiation-mediated oxidative damages and the antioxidant capacity of the erythrocytes was observed in the hours after radiation exposure. Antioxidant enzyme activities, mainly catalase and glutathione peroxidase, were found to decrease after irradiation. The development of a radiation-induced oxidative stress probably explains the reorganization of the fatty acid pattern 72 h after radiation exposure. The phosphatidylethanolamine (PE) fatty acids of the (n-3) and (n-6) series decreased, while the PE saturated fatty acid content increased. All these modifications may be involved in the variation of the biophysical properties of the membranes that we noted after radiation exposure. Specifically, we observed that the lipid compartment of the membrane became more fluid while the lipid-protein membrane interface became more rigid. Taken together, these findings reinforce our understanding that the cell membrane is a significant biological target of radiation. Thus the role of the biological membrane in the expression and course of cell damage after radiation exposure must be considered.

Nanostructural Changes in the Cell Membrane of Gamma-Irradiated Red Blood Cells

“…However, RBCs have the ability to resist such deformation and recover. Benderitter et al [32]. demonstrated that the level of lipid peroxidation increased in the hours after radiation exposure but was not observed after 3 days post-irradiation.…”

Low dose radiation response curves, networks and pathways in human lymphoblastoid cells exposed from 1 to 10cGy of acute gamma radiation

“…There are associated increases in mitochondrial permeability and calcium release as well as reactive oxygen species [25,29,30]. DNA, cellular membranes, and organelles are important targets of high-dose radiation [26,31,32], but their roles after exposure to low doses are poorly understood.…”

UV degradation of deoxyribonucleic acid

“…However, how such radiation damage is induced at molecular level still not well understood [2]. When ionizing radiation interacts with matter it produces, in very short times (femtoseconds), a large number of ions, radicals, excited neutrals and ballistic secondary electrons with initial kinetic energies below 100 eV [3,4], which can subsequently cause both physical and chemical modification in the biological media.…”