[Potassium transport in erythrocytes from patients with gentamicin intolerance]

A study was made of rubidium (potassium analog) influxes via ouabain-sensitive Na/K pump, bumetanide-sensitive cotransport and resistant to ouabain bumetanide membrane ion pathways and of the intracellular potassium and sodium contents in red blood cells from patients with high gentamicin sensitivity (GSP) and healthy patients (HP). It is found that red blood cells from two groups of donors do not differ in both intracellular potassium and sodium contents and pump-mediated rubidium influxes, however, bumetanide-sensitive rubidium influxes were twice as low in GSP as compared to HP (0.28 against 0.46 mumole per gram of hemoglobin). In the presence of gentamicin (10(-6) M) bumetanide-sensitive rubidium influxes were shown to decrease in red blood cells of GSP, being unchanged in erythrocytes of HP. It is suggested that the increased rates of hemolysis in response to hypotonicity in red blood cells of GSP may be due to a decreased activity of bumetanide-sensitive cotransport in plasma membrane of these cells.