Lithium Interferes with the Urinary Excretion of Phenolsulfonphthalein in Rats: Involvement of a Reduced Content of α-Ketoglutarate, the Driving Force for Organic Anion Transporters OAT1 and OAT3, in the Kidney Cortex.

Aims: Lithium is effective in the treatment for bipolar disorder and is known to influence renal functions. The purpose of this study was to examine the effects of lithium on the renal organic anion transport system. Methods: Pharmacokinetic experiments using rats and Western blotting were conducted. Results: Until 60 min after the intravenous injection of phenolsulfonphthalein, a typical substrate of the renal organic anion transporters, as a bolus, 41.2% of the dose was recovered in the urine, and the infusion of lithium chloride dose-dependently interfered with its renal excretion. No significant changes were observed in the expression levels of rat organic anion transporters rOAT1 and rOAT3, and the content of α-ketoglutarate, the driving force for both transporters, was significantly decreased in the kidney cortex of rats administered lithium. Conclusion: These findings represented the dysfunction of the renal organic anion transport system in rats by lithium. As the mechanism, the reduced driving force for rOAT1 and rOAT3 was suggested to be involved at least in part. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]