Effect of taurine on total parenteral nutrition-associated cholestasis

A decrease in the formation/secretion of bile has been well documented in animals on total parenteral nutrition (TPN). Either an excess or an imbalance of amino acids (AA) has been most often implicated. In view of recent work showing that taurine promotes bile flow, bile acid secretion, and protects against hepatotoxic bile acids, the effect of adding taurine (15 mg/dL) to an AA solution was examined in guinea pigs on TPN for 3 days. The TPN-taurine group had a larger bile flow than the group without taurine and had bile acid secretory rates (BASR) similar to those of controls who were on saline by central catheter and had free access to food. Bile composition showed an increase in the secondary bile acid, 7-ketolithocholate and a concomitant decrease in chenodeoxycholate (CDC) in both experimental groups. Taurine led to a reversal of the usual predominance of glycine over taurine conjugated bile acids as well as to increases in HCO3 in cholesterol secretion. In response to a challenge with a large load of CDC, the TPN-taurine animals increased their BASR beyond those observed in the two other groups. These observations suggest that the addition of taurine to TPN solutions could play a role in the prevention of altered biliary function associated with AA solutions.