The effect of lead on lactate formation, ATP level and membrane ATPase activities in human erythrocytes in vitro.

Lead ions inhibit aerobic glycolysis and diminish ATP level in human erythrocytes in vitro. Magnesium partly abolishes this inhibitory effect of lead on lactate formation by stimulation of Mg-dependent enzymes. Lead ions also inhibit the (Na, K) ATPase activity of the erythrocyte membranes. This effect is seen after the direct adding of lead acetate to erythrocyte ghosts, as well as in the ghosts obtained after preincubation of intact erythrocytes with lead acetate, prior to cell membrane isolation (Ca, Mg) ATPase is less sensitive to lead and (Mg) ATPase is practically insensitive. During these studies a protective effect of glucose was found. The inhibition of (Na, K) ATPase by lead ions, observed after incubation of human erythrocytes, as an experimental model, may indicate a similar sensitivity of membrane (Na, K) ATPases from other cells during their in vitro exposure to lead, especially from the nervous cells, where (Na, K) ATPase participates in the process of cell surface repolarization.