The distribution of lithium between erythrocytes and plasma: in vitro studies on the transport of lithium in human erythrocytes

Distribution ratiors of intracellular lithium (Lii) and extracellular Li (Lie) were determined in vitro after incubation of Li-free or Li-loaded red cells in media containing varying Li-concentrations (37 degrees C, pH 7.4). The distribution ratios Lii/Lie obtained in vitro after 24 h of incubation corresponded to those found in vivo. The results indicate that Li can be extruded from red cells against an electrochemical gradient. This Li extrusion is inhibited by replacing extracellular Na+ with K+ or choline+, but is not affected by ouabain or by glucose depletion.