KINETICS OF ELECTROINDUCED PORES AS A PROBE OF MEMBRANE MODIFICATION PRODUCED BY IONIZING-RADIATION

In this work, we have attempted to demonstrate that the study of eryth rocyte electroporation can be used to characterize modifications induc ed at the membrane level by the exposure of living cells to ionizing r adiation. Wistar rats were contaminated by chronic ingestion of tritia ted water (HTO) in a range of absorbed doses between 0 and 49 cGy. Ery throcyte suspensions were subjected to single electrical pulses and, b y modelling the time evolution of light absorption al 610 nm, kinetic parameters describing the electroporated suspension were calculated. A significant increase in the apparent haemolysis rate was observed for the irradiated erythrocytes when subjected to long, high-intensity el ectrical pulses. In milder electropulsation conditions, when the rever sible electroporation process was favoured, the irradiated erythrocyte s showed a significant increase in both the radius pore resealing rate and the maximum area of the electroporated surface (for a dose of 49 cGy) compared with the control. The results indicate that the modifica tions of the parameters due to the effects of irradiation on the eryth rocytes reflect an increase in the membrane fluidity without disturbin g the association between the cytoskeleton and membrane proteins. (C) 1997 Elsevier Science S.A.