Objective: Hepatic synthesis and plasma levels of glutathione are markedly decreased in chronic liver disease. Since glutathione turnover is highest in kidneys we examined whether changes of kidney glutathione occur in chronic cholestasis and whether they are related to kidney dysfunction in liver disease. Methods: Kidney and plasma reduced (GSH) and oxidized (GSSG) glutathione were measured (i) in bile duct ligated (BDL) rats, (ii) in healthy rats after bile acid loading to mimic cholestasis, and (iii) after irreversible inhibition of glutathione synthetase with buthionine-sulfoximine (BSO) where also glutathione consumption, urine volume and sodium excretion were estimated. In addition, -glutamylcysteine synthetase (-GCS) mRNA, protein and enzymatic specific activity were measured in kidney tissue after BDL. Results: Following BDL, kidney GSH and GSSG increased within hours by 67% and 66%. The increases were not related to plasma glutathione that decreased below control values. Intravenous bile acid loading caused identical increases of GSH and GSSG as after BDL when glycine- or taurine-conjugated dihydroxy bile acids were administered. Glutathione consumption as estimated after blocking of de-novo synthesis with BSO was significantly increased after bile duct ligation (127 vs. 44 nmol/g/min). -GCS mRNA and enzymatic specific activity were significantly reduced 5 days after BDL whereas protein concentrations did not change. The urinary sodium concentration was 70% lower in BDL than in controls. Depletion of renal glutathione normalized sodium excretion by increasing urinary sodium concentration and urine volume. Conclusion: The increase of kidney glutathione after BDL seems to be mediated by an increase of plasma bile acids and is critically related to sodium retention. The increase in GSH consumption despite a reduced -GCS activity indicates a decreased GSH turnover tentatively due to reduced renal GSH-efflux by competition with organic anions at membrane transport proteins.