1. Obstructive jaundice sensitizes the kidney to anoxic damage. To clarify further this phenomenon the effect of unilateral infusion of bile on kidney function was studied. The contralateral intact kidney served as control.
2. Intrarenal infusion of diluted bile (1:10) resulted in an ipsilateral fourfold increase in mean rate of urinary flow (P < 0.01), threefold increase in mean fractional excretion of sodium (P < 0.05) and more than 50% increase in mean rates of potassium excretion (P < 0.05). Urinary flow rate and electrolyte excretion returned to baseline upon cessation of bile infusion. The mean clearances of inulin and p-aminohippurate were unchanged during intrarenal bile infusion.
3. Intrarenal infusion of isotonic taurocholate solution (20 mmol/l) mimicked the diuretic, natriuretic and kaliuretic effects of diluted bile, whereas intrarenal infusion of bilirubin did not cause any change in the excretion of electrolytes.
4. It is concluded that increase in circulating bile acids rather than hyperbilirubinaemia may alter kidney function during obstructive jaundice. Acute cholaemia may cause volume depletion by increasing urinary salt loss. This in turn may aggravate the direct nephrotoxicity of circulating bile compounds.