EFFECTS OF HYPERTONIC SOLUTIONS AND OF SOME ANION TRANSPORT INHIBITORS ON THE ELECTROPHORETIC MOBILITY OF HUMAN ERYTHROCYTES

Under the conditions of physiological pH and ionic strength, the human erythrocytes exhibit a negative electrophoretic mobility (EM) due to the negative surface charge. In this research we studied the effects on the EM of: 1) the hypertonicity of the suspending medium, 2) the inhibition of anion exchange by means of some powerful molecules (phenylglyoxal, PG and two PG derivatives: HNPG and 3-MOPG kindly given by L. Zaki, Frankfurt). The experiments were performed in a horizontal cylindrical capillary by the microscope method at room temperature. In all the experiments the erythrocyte migration velocity resulted linearly related to the applied electric field (0-15 V/cm). In isotonic solution a mean velocity (± SE) of 1.47±0.04 (n=14) μm/s V/cm was obtained. The red blood cells suspended in hypertonic medium (400 mOsm) reduced their EM of about 16.2%. The incubation (30 min) of erythrocytes in solution containing PG (5mM), HNPG (2 mM) or 3-MOPG reduced EM respectively about 16.5%, 11.5% and 13.5%. HNPG reduction was reversible, those caused by PG and 3-MOPG were not. For the inhibitors the major role possibly lies in their ability to reduce the negative surface charge interacting with transport systems. For the hypertonic solution we must take into account the changes of size and shape which might mask partially the electrical charges for a new make up of the membrane surface