FREEZE-FRACTURING STUDIES ON HUMAN ERYTHROCYTE MEMBRANES EFFECTED BY EXTERNAL PULSED ELECTRICAL FIELD
Zhang Jin-zhu Kong Ke-jian (Dept. of Cell Biophysics Institute of Biophysics, Academia Sinica.) Lu Qi-wu Dong Ren-jie (Technical Center of Analyses and Measurements Institute of Biophysica, Academia Sinica.)
Electron microscopic observations made on the freeze-fracturing replica of plasma membranes of human erythrocytes exposed to external pulsed electrical field have shown that under experimental conditions, some particles and fibers appear around the cells pulsed by higher intensities than 3 KV/cm. Electrophoretical analysis for the cell suspensions has proved that some of these particles and fibers are membrane proteins and membrane skeleton proteins escaped from cells. On account of this, the stability of cell membrane decreases and the cells are easy to change their shapes and to form pseudopodium like st- ructures and protein free membrane lipids tend to form vesicular structure in cytop-lasma. The changes of protein-protein interactions and protein-lipid interactions caused by electrical field are considered as the dominating mechanism of cell membrane electroporation. An argument about intra-membrane particles (IMPS) and other possibilities of the contributions to IMPS, for instance, ice crystals formation which related to membrane hydrophilic or hy-drophobic properties were discussed in this paper.