Bilirubin excretion into bile after partial hepatectomy in rats

Biliary excretion of bilirubin was studied in Wistar rats at different intervals following two-thirds hepatectomy. Endogenous bilirubin excretion was not significantly modified during liver regeneration. The maximal biliary excretion rate (Tm) of bilirubin, expressed per 100 g of body weight, significantly decreased immediately after hepatectomy with a recovery to presurgery values by 16 days. Values expressed per g of liver were significantly lowered only by 12- and 24h posthepatectomy. In these early periods there was a significant increase in the liver concentration of unconjugated bilirubin and a decrease in bile flow following bile pigment infusion. Maximal excretion of bilirubin in the rat seems to change parallel to the regeneration of liver mass except during the first 24h in which the inhibitory effects exerted by the high load of exogenous bilirubin would cause a decline in its own biliary output with an added cholestatic effect.