DIETARY POTASSIUM EFFECTS ON LITHIUM CONCENTRATION AND TOXICITY ON HAMSTERS

Lithium can be toxic in rodents and human patients at concentrations w ithin the therapeutic range for treatment of affective disorders. Diet containing supplemental potassium reduced lithium-induced weight loss in hamsters following daily injections of 3 mmol LiCl/kg for 7-10 day s. Potassium supplementation also decreased lithium concentrations in peripheral tissues, but no in brain, after repeated lithium administra tion. Repeated lithium injection lowered the concentration of potassiu m in peripheral tissues, but tissue potassium was not restored by diet ary potassium supplementation. Toxic effects of single injections of 1 -10 mmol LiCl/kg were unaffected by dietary potassium. Lithium concent rations in plasma, brain, or peripheral tissues 6-hr after injection o f 5 mmol LiCl/kg were also not altered by potassium diet. These data s uggest that interactions between lithium and potassium diet differ in peripheral tissues compared to the central nervous system, and after a cute versus chronic lithium administration.