CONICET | Buscador de Institutos y Recursos Humanos

Reactive Oxygen Species (ROS) are by-products of the normal aerobic metabolism whose dynamics and steady-state concentration are regulated by precise mechanisms of redox balance that prevent their potentially toxic effects. Under prolonged and/or high-intensity oxidative stress conditions, large amounts of hydroperoxidized lipids (ROOH) can beaccumulated in cell membranesas the first relatively stable products of the ROS-mediated process known as Lipid peroxidation (LPO). Numerous biophysical studies have shown how LPO impact on the structure and organization of lipid membranes, but its effects on the functionality and the electrical behavior of the membrane are only partially elucidated. Taking into account the evidences about a dual concentration-dependent role of ROS as toxic and signaling molecules, the present work is focused on the study of the oxidative damage effects on the conductance process dynamics in Bilayer Lipid Membranes (BLMs), with the aim to elucidate how the electrical signaling processes can be affected under stressful conditions, how the membrane self-organizes to respond to external (electrical) perturbations depending on the oxidative damage severity, to finally discuss the evidence that support the hypothesis that the conductance process dynamics could be modulated by ROS through non-specific mechanisms, without protein ion channels involvement. Our results show that, oxidative damage favors the dynamical evolution of the membrane system towards a self-organized critical state characterized by the emergence of long term-memory and scale invariance properties of the conductance process when certain ROOH concentration and energy thresholds are overcome. This critical state appears to be strongly associated to the ion lipid conductive pores formation and a non-linear (non-ohmic) behavior of the electrical parameters