Uptake of taurocholate by freshly isolated hepatocytes from fetal and newborn rabbits.

During early postnatal maturation a significant increase in the rate constant of translocation (Michaelis-Menten constant; Km) for taurocholate uptake occurs in isolated rabbit hepatocytes. This age-dependent change is related to a decrease in the efficiency of uptake for taurocholate and is probably associated with changes in the receptor or its microenvironment within the plasma membrane. Cholic acid conjugates (taurocholic and glycocholic acids) are the predominant bile acids found in the premature and neonatal human. It is therefore of interest that in the fetal and neonatal rabbit we have found a developmentally dependent alteration of taurocholic acid transport.