Effect of lead in vitro on water metabolism and osmotic fragility of human erythrocytes.

The addition of lead to normal human blood was previously found to cause a decrease in erythrocyte osmotic fragility in vitro. The mechanism of the decreased osmotic fragility caused by lead has not been completely clarified, but the following hypothesis has been proposed. Lead causes a leakage of water from erythrocytes, thus more water can enter the cell before haemolysis occurs. There has been no report, however, of the direct measurement of the intracellular water content of erythrocytes treated with lead. This study has tried to clarify the relation between intracellular water and the osmotic fragility of lead-treated erythrocytes in vitro. The results showed that 0.05 microM/ml of lead decreased the osmotic fragility, the intracellular water content, and intracellular potassium and mean corpuscular volume, increased the plasma water content and trapped water content, and contracted the erythrocyte shape. These changes corresponded well with each other, and close coincidence of the osmotic fragility and the intracellular water content was also observed.