Choleresis and bile pigment excretion in the nutria.

Mean excretory rates of endogenous biliverdin (BV) and bilirubin (BR) in nutria were determined to be 6.0 +/- 1.0 and 0.67 +/- 0.10 microgram/min/kg, respectively. Endogenous bile flow was 33 +/- 7.0 microliter/min/kg. Infusion of sodium taurocholate at rates above 0.1 mumol/min/kg resulted in cholestasis. Hepatic transport maxima for BR conjugates following the infusion of unconjugated BR were 120 and 130 micrograms/min/kg. Although nutria excrete predominantly BV like avian and reptilian species, they differ by readily excreting an exogenous load of unconjugated BR.