Dielectric Breakdown Measurements of Human and Bovine Erythrocyte Membranes Using Benzyl Alcohol As a Probe Molecule

Dielectric breakdown of intact erythrocytes and subsequent haemolysis in the presence of increasing concentrations of benzyl alcohol were investigated by means of an electrolytical discharge chamber and a hydrodynamic focusing Coulter Counter. Low concentrations of the drug stabilized human and bovine erythrocytes against haemolysis induced by dielectric breakdown of the cell membrane in isotonic solutions, while high concentrations caused lysis similar to hypotonic and mechanical haemolysis. The stabilizing effect of the drug on electrically induced haemolysis depends on the pulse length of the applied electric field. The critical dielectric breakdown voltage of the membranes of intact cells decreases progressively with increasing benzyl alcohol concentrations, at which the membrane is also more stabilized against electrical and osmotic haemolysis. Occasionally, an increase in the dielectric breakdown voltage is observed at drug concentrations at which lysis occurs. A similar depedence of the breakdown voltage on drug concentration was found for human erythrocyte ghost cells prepared by dielectric breakdown. The results are consistent with the electromechanical model suggested for the dielectric breakdwon mechanism and with the assumption of Metcalfe, using NMR and ESR techniques, that the fluidity of the membrane increases with increasing benzyl alcohol concentration.