Erythrocyte Lithium Transport in Bipolar Affective Disorders

Erythrocyte lithium influx and efflux were investigated in vitro in patients with bipolar affective disorders and in age- and sex-matched healthy controls. To explore the components of lithium influx and efflux five selected inhibitors (ouabain, phloretin, p-chloromercury benzene sulfonate [PCMBS], 4,4'-diisothiocyano-2,2'-disulfonic acid stilbene, and lanthanium chloride) were employed. The mean values of lithium influx were similar in both populations of erythrocytes. The addition of ouabain and phloretin reduced lithium influx, but this effect was comparable in both patients and controls. PCMBS had an accelerating effect, and this was more pronounced in patients. Total erythrocyte lithium efflux from lithium-containing erythrocytes was comparable in both patients and controls. The addition of phloretin reduced RBC lithium efflux, the magnitude of this parameter, however, was similar in patients and controls. Erythrocyte lithium efflux was accelerated in the presence of PCMBS, and this effect was greater in patients. The relevance of these findings to the postulated cell membrane defect in affective disorders is evaluated.