Inhibition of bile formation by high doses of taurocholate in the perfused rat liver.

Sodium taurocholate was administered to the in situ perfused liver of male Sprague Dawley rats at various rates below (57 and 114 nmol/min -g liver) and above (228 and 456 nmol/min -g liver) its biliary transport maximum (Tm) to study its effect on bile formation. As expected, bile flow increased with increasing dose until maximal bile salt excretion was reached. By contrast, during taurocholate infusions exceeding the taurocholate-Tm, bile flow and bile salt excretion decreased. Under those conditions, a given bile salt excretion was associated with a smaller volume of bile. A relationship between these effects and the concentration of taurocholate in the perfusate (160 to 860 nmol/ml) was suggested by the observation that bile formation returned toward normal when the taurocholate concentration was lowered by exchange of the perfusate.