An irreversible effect of lithium administration to patients.

1 Lithium administration to patients leads to a pronounced inhibition (about 90%) of the choline transport system in erythrocytes. The transport system does not recover when ghosts are prepared from the erythrocytes, thereby removing intracellular as well as extracellular lithium. 2 When a patient is taken off lithium, the choline transport in erythrocytes recovers only very slowly over a period of three months, i.e. at about the same rate at which the erythrocytes that had been exposed to lithium are replaced by new cells. 3 It is concluded that therapeutic concentrations of lithium produce an irreversible inhibition of the choline transport system in human erythrocytes.