[Distribution and elimination behavior of lithium in young and adult rats following acute administration of various inorganic cations and anions].

In 5- and 105-day-old rats the influence of intraperitoneally administered cations (Na+, K+, NH4+) and anions (Cl-, HCO3-) on the age-dependent distribution- and elimination processes of LiCl (0.3 mmol Li+/100 g b.wt., i.p.) were determined. After an acute load of sodium ions the renal elimination of lithium is increased and the half life (t 1/2 serum) is shortened. Compared with increased dosages of NaHCO3 equal doses of NaCl are more effective. Interactions in kidney between lithium and definite anions were observed on the bicarbonate ion only. The administrations of KCl or NH4Cl have no important consequences on lithium kinetics. Although the transport of lithium in kidney does not occur by the Na+K+-pump, renal and extrarenal interactions between sodium and lithium ions seem to exist. The expulsion of lithium out of the ICR by an extensive sodium load (decrease of VdLi+) may precede the observed inhibition on renal lithium reabsorption or both processes occur simultaneously.