Taurocholate increases the biliary output of bilirubin pigments in the rat, due to haemolysis

Abstract

In order to investigate the effect of bile salts on the biliary transport of bilirubin, we infused rats with taurocholate at 1–3 μmol/min/kg body weight. When administered in saline, taurocholate induced haemolysis, and a dosedependent increase in biliary excretion and serum concentration of all bilirubin pigments. The addition of human or rat serum albumin to the infusate, at an albuminataurocholate molar ratio equal to or above 200, completely prevented haemolysis and the above-mentioned alterations in bilirubin transport, without any change in the bile acid output. In order to mimic a haemolytic condition, an erythrocyte haemolysate was further added to the taurocholate-alburnin solution. This again resulted in an increased bilirubin output. We suggest that taurocholate treatment increases bilirubin output due to the increased load of the pigment on the liver, as a result of the bile acid-induced haemolysis.