The Effect of Lithium on Cation Transport Measuredin vivoin Patients Suffering from Bipolar Affective Illness

We have investigated cation transportin vivoin patients being treated with lithium for bipolar affective illness by studying the disposition of rubidium after an oral load of rubidium chloride. The rate of erythrocyte cation transport was increased in the patients when compared with matched healthy volunteers. However, the rate ofin-vivoerythrocyte rubidium accumulation in the euthymic treated patients was significantly lower than in a matched group of unmedicated manic patients. The regulation of specific pathways for cation transport may be altered in individuals predisposed to affective illness.

POTASSIUM-DEPENDENT SODIUM EXTRUSION BY CELLS OF PORPHYRA PERFORATA, A RED MARINE ALGA

Potassium-free artificial sea water causes a loss of cell potassium and a gain of cell sodium in Porphyra perforata, which is not attributable to an inhibition of respiration. On adding KCl or RbCl to such low potassium, high sodium tissues, net accumulation of potassium or rubidium takes place, accompanied by net extrusion of sodium. Rates of potassium or rubidium accumulation and sodium extrusion are proportional to the amount of KCl or RbCl added only at low concentrations. Saturation of rates is evident at KCl or RbCl concentrations above 20–30 mM, suggesting the role of an ion carrier mechanism of transport. Evidence for and against mutually dependent sodium extrusion and potassium or rubidium accumulation is discussed.